

<!-- DFS Xcelerate Instance Document - http://www.dfsco.com/financial-services/ -->
<!-- Version:  6.23.6 -->
<!-- Round: 2 -->
<!-- Creation date: 2018-05-10T14:16:42Z -->
<!-- Copyright (c) 2017 Donnelley Financial, LLC. All Rights Reserved. -->
<xbrl xmlns="http://www.xbrl.org/2003/instance" xmlns:xbrll="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:iso4217="http://www.xbrl.org/2003/iso4217" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:us-gaap="http://fasb.org/us-gaap/2017-01-31" xmlns:dei="http://xbrl.sec.gov/dei/2014-01-31" xmlns:galt="http://www.galectintherapeutics.com/20180331" xmlns:us-types="http://fasb.org/us-types/2017-01-31" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrldi="http://xbrl.org/2006/xbrldi" xmlns:stpr="http://xbrl.sec.gov/stpr/2011-01-31" xmlns:country="http://xbrl.sec.gov/country/2017-01-31" xmlns:currency="http://xbrl.sec.gov/currency/2017-01-31" xmlns:exch="http://xbrl.sec.gov/exch/2017-01-31" xmlns:naics="http://xbrl.sec.gov/naics/2017-01-31" xmlns:invest="http://xbrl.sec.gov/invest/2013-01-31" xmlns:sic="http://xbrl.sec.gov/sic/2011-01-31" xmlns:negated="http://www.xbrl.org/2009/role/negated" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:utr="http://www.xbrl.org/2009/utr">
  <xbrll:schemaRef xlink:type="simple" xlink:arcrole="http://www.xbrl.org/2003/linkbase" xlink:href="galt-20180331.xsd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xbrll="http://www.xbrl.org/2003/linkbase" />
  <galt:FairValueOfAssetContributedToJointVenture contextRef="eol_PE87402---1810-Q0001_STD_0_20140131_0_1547987x1675610_1552126x1734694_1555137x1558637" unitRef="iso4217_USD" decimals="0" id="id_10142697_72BBCE3C-1421-4F58-B094-D7EE6145F09B_3003_1">400000</galt:FairValueOfAssetContributedToJointVenture>
  <us-gaap:MinorityInterestOwnershipPercentageByParent contextRef="eol_PE87402---1810-Q0001_STD_0_20140131_0_1552126x1734694" unitRef="pure" decimals="INF" id="id_10142697_72BBCE3C-1421-4F58-B094-D7EE6145F09B_4003_3">0.500</us-gaap:MinorityInterestOwnershipPercentageByParent>
  <us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 contextRef="eol_PE87402---1810-Q0001_STD_0_20170228_0_1558176x1744662" unitRef="iso4217_USD_per_shares" decimals="INF" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_2001_3">5.00</us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1>
  <us-gaap:SharePrice contextRef="eol_PE87402---1810-Q0001_STD_0_20170228_0_1558176x1744662" unitRef="iso4217_USD_per_shares" decimals="INF" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_2001_5">1.86</us-gaap:SharePrice>
  <galt:CommissionsAsPercentageOfGrossOfferingProceeds contextRef="eol_PE87402---1810-Q0001_STD_0_20170519_0_1550105x1766096" unitRef="pure" decimals="3" id="id_10142697_B51FF437-EB1C-45B5-BC48-009D5815BEB3_1001_1">0.030</galt:CommissionsAsPercentageOfGrossOfferingProceeds>
  <galt:AggregateOfferingPrice contextRef="eol_PE87402---1810-Q0001_STD_0_20170519_0_1550105x1766096" unitRef="iso4217_USD" decimals="-5" id="id_10142697_B51FF437-EB1C-45B5-BC48-009D5815BEB3_1001_0">30000000</galt:AggregateOfferingPrice>
  <us-gaap:DebtInstrumentInterestRateStatedPercentage contextRef="eol_PE87402---1810-Q0001_STD_0_20171219_0_1547993x1728624_1553398x1558014" unitRef="pure" decimals="4" id="id_10142697_8977F936-D169-4524-92E8-6A9F54714BEE_1001_2">0.0151</us-gaap:DebtInstrumentInterestRateStatedPercentage>
  <us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity contextRef="eol_PE87402---1810-Q0001_STD_0_20171219_0_1547993x1728624_1553398x1558014" unitRef="iso4217_USD" decimals="-6" id="id_10142697_8977F936-D169-4524-92E8-6A9F54714BEE_1001_0">10000000</us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity>
  <dei:EntityCommonStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20180508_0" unitRef="shares" decimals="INF" id="id_10142697_E3DF0DBA-6088-4A92-BF3B-34BCC5FE8103_2_500005">37740647</dei:EntityCommonStockSharesOutstanding>
  <galt:CommissionsAsPercentageOfGrossOfferingProceeds contextRef="eol_PE87402---1810-Q0001_STD_0_20140330_0_1550105x1587045" unitRef="pure" decimals="3" id="id_10142697_C990EBC7-4C96-41D8-B152-935895895C9C_1001_1">0.030</galt:CommissionsAsPercentageOfGrossOfferingProceeds>
  <galt:AggregateOfferingPrice contextRef="eol_PE87402---1810-Q0001_STD_0_20140330_0_1550105x1587045" unitRef="iso4217_USD" decimals="-5" id="id_10142697_C990EBC7-4C96-41D8-B152-935895895C9C_1001_0">30000000</galt:AggregateOfferingPrice>
  <us-gaap:CashAndCashEquivalentsAtCarryingValue contextRef="eol_PE87402---1810-Q0001_STD_0_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1002_16">13644000</us-gaap:CashAndCashEquivalentsAtCarryingValue>
  <us-gaap:CommonStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_49">50000000</us-gaap:CommonStockSharesAuthorized>
  <us-gaap:CommonStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_51">37645971</us-gaap:CommonStockSharesOutstanding>
  <us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_25289D46-C2CD-492B-A0F0-4333D49920A3_3001_1">951181</us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares>
  <us-gaap:ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="shares" decimals="0" id="id_10142697_410AC137-1A6D-4639-8393-AC1CAB7918EC_2001_0">500000</us-gaap:ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights>
  <us-gaap:CommonStockParOrStatedValuePerShare contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD_per_shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_48">0.001</us-gaap:CommonStockParOrStatedValuePerShare>
  <us-gaap:CommonStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_50">37645971</us-gaap:CommonStockSharesIssued>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B64E757-74DE-4210-AE6A-855267D0EFD9_3001_6">5615263</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_2A1B60B4-84A9-409D-955F-1C6DD2E32E2A_3001_6">4.26</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice>
  <us-gaap:RetainedEarningsAccumulatedDeficit contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_53">-185711000</us-gaap:RetainedEarningsAccumulatedDeficit>
  <us-gaap:Liabilities contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_13">2283000</us-gaap:Liabilities>
  <us-gaap:LiabilitiesAndStockholdersEquity contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_55">4931000</us-gaap:LiabilitiesAndStockholdersEquity>
  <us-gaap:EmployeeRelatedLiabilitiesCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_E9569066-8B58-4697-944D-B0932A34E402_1001_1">314000</us-gaap:EmployeeRelatedLiabilitiesCurrent>
  <us-gaap:AccountsPayableCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_9">1151000</us-gaap:AccountsPayableCurrent>
  <us-gaap:StockholdersEquity contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_54">925000</us-gaap:StockholdersEquity>
  <us-gaap:CommonStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_47">38000</us-gaap:CommonStockValue>
  <us-gaap:AdditionalPaidInCapital contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_52">179359000</us-gaap:AdditionalPaidInCapital>
  <us-gaap:AccruedProfessionalFeesCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_E9569066-8B58-4697-944D-B0932A34E402_1001_0">51000</us-gaap:AccruedProfessionalFeesCurrent>
  <us-gaap:CommitmentsAndContingencies contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" xsi:nil="true" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_14" />
  <us-gaap:LiabilitiesCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_12">2283000</us-gaap:LiabilitiesCurrent>
  <us-gaap:AccruedLiabilitiesCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_10">1132000</us-gaap:AccruedLiabilitiesCurrent>
  <us-gaap:AssetsCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_4">4673000</us-gaap:AssetsCurrent>
  <us-gaap:CashAndCashEquivalentsAtCarryingValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_2">3988000</us-gaap:CashAndCashEquivalentsAtCarryingValue>
  <us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="0" id="id_10142697_25289D46-C2CD-492B-A0F0-4333D49920A3_3001_0">1972000</us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized>
  <us-gaap:Assets contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_6">4931000</us-gaap:Assets>
  <us-gaap:OtherAssetsNoncurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_5">258000</us-gaap:OtherAssetsNoncurrent>
  <us-gaap:PrepaidExpenseAndOtherAssetsCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_3">685000</us-gaap:PrepaidExpenseAndOtherAssetsCurrent>
  <galt:UndesignatedCapitalStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_25">20000000</galt:UndesignatedCapitalStockSharesAuthorized>
  <galt:UndesignatedCapitalStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_26">20000000</galt:UndesignatedCapitalStockSharesOutstanding>
  <galt:UndesignatedCapitalStockParValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD_per_shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_24">0.01</galt:UndesignatedCapitalStockParValue>
  <galt:UndesignatedCapitalStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1_23">0</galt:UndesignatedCapitalStockValue>
  <us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1547993x1728624_1553398x1558014" unitRef="iso4217_USD_per_shares" decimals="0" id="id_10142697_8977F936-D169-4524-92E8-6A9F54714BEE_1003_4">5</us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1>
  <us-gaap:ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1547993x1728624_1553398x1558014" unitRef="shares" decimals="-6" id="id_10142697_8977F936-D169-4524-92E8-6A9F54714BEE_1003_3">1000000</us-gaap:ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights>
  <us-gaap:LinesOfCreditCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1547993x1728624_1553398x1558014" unitRef="iso4217_USD" decimals="INF" id="id_10142697_8977F936-D169-4524-92E8-6A9F54714BEE_1003_5">0</us-gaap:LinesOfCreditCurrent>
  <us-gaap:CommonStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1549585x1749940_1550105x1727852" unitRef="shares" decimals="INF" id="id_10142697_888DA2D2-DC4A-48CC-BD50-963A56B7D31D_3001_1">1629</us-gaap:CommonStockSharesIssued>
  <us-gaap:CommonStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1549585x1749940_1550105x1727852_1559480x1552364" unitRef="iso4217_USD" decimals="0" id="id_10142697_888DA2D2-DC4A-48CC-BD50-963A56B7D31D_4001_0">100000</us-gaap:CommonStockValue>
  <us-gaap:MinorityInterestOwnershipPercentageByParent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1552126x1734694" unitRef="pure" decimals="3" id="id_10142697_72BBCE3C-1421-4F58-B094-D7EE6145F09B_4001_3">0.798</us-gaap:MinorityInterestOwnershipPercentageByParent>
  <us-gaap:TemporaryEquitySharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1553185" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1001_18">176</us-gaap:TemporaryEquitySharesOutstanding>
  <us-gaap:TemporaryEquitySharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1553185" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1001_17">176</us-gaap:TemporaryEquitySharesIssued>
  <us-gaap:TemporaryEquitySharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1553185" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1001_16">1000</us-gaap:TemporaryEquitySharesAuthorized>
  <us-gaap:TemporaryEquityCarryingAmountAttributableToParent contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1553185" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1001_15">1723000</us-gaap:TemporaryEquityCarryingAmountAttributableToParent>
  <us-gaap:TemporaryEquityLiquidationPreference contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1553185" unitRef="iso4217_USD" decimals="0" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1001_20">1760000</us-gaap:TemporaryEquityLiquidationPreference>
  <us-gaap:TemporaryEquityAggregateAmountOfRedemptionRequirement contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1553185" unitRef="iso4217_USD" decimals="0" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1001_19">7957000</us-gaap:TemporaryEquityAggregateAmountOfRedemptionRequirement>
  <us-gaap:PreferredStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1668932" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2001_45">2508000</us-gaap:PreferredStockSharesOutstanding>
  <us-gaap:PreferredStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1668932" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2001_44">2508000</us-gaap:PreferredStockSharesIssued>
  <us-gaap:PreferredStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1668932" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2001_43">2508000</us-gaap:PreferredStockSharesAuthorized>
  <us-gaap:PreferredStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1668932" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2001_42">1224000</us-gaap:PreferredStockValue>
  <us-gaap:PreferredStockLiquidationPreferenceValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1668932" unitRef="iso4217_USD" decimals="0" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2001_46">2508000</us-gaap:PreferredStockLiquidationPreferenceValue>
  <us-gaap:PreferredStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1708936" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3001_30">1377500</us-gaap:PreferredStockSharesOutstanding>
  <us-gaap:PreferredStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1708936" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3001_29">1377500</us-gaap:PreferredStockSharesIssued>
  <us-gaap:PreferredStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1708936" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3001_28">1742500</us-gaap:PreferredStockSharesAuthorized>
  <us-gaap:PreferredStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1708936" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3001_27">557000</us-gaap:PreferredStockValue>
  <us-gaap:PreferredStockLiquidationPreferenceValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1708936" unitRef="iso4217_USD" decimals="0" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3001_31">1377500</us-gaap:PreferredStockLiquidationPreferenceValue>
  <us-gaap:PreferredStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1717432" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4001_35">900000</us-gaap:PreferredStockSharesOutstanding>
  <us-gaap:PreferredStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1717432" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4001_34">900000</us-gaap:PreferredStockSharesIssued>
  <us-gaap:PreferredStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1717432" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4001_33">900000</us-gaap:PreferredStockSharesAuthorized>
  <us-gaap:PreferredStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1717432" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4001_32">1761000</us-gaap:PreferredStockValue>
  <us-gaap:PreferredStockLiquidationPreferenceValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1717432" unitRef="iso4217_USD" decimals="0" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4001_36">1800000</us-gaap:PreferredStockLiquidationPreferenceValue>
  <us-gaap:PreferredStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1727389" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5001_40">2100000</us-gaap:PreferredStockSharesOutstanding>
  <us-gaap:PreferredStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1727389" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5001_39">2100000</us-gaap:PreferredStockSharesIssued>
  <us-gaap:PreferredStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1727389" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5001_38">2100000</us-gaap:PreferredStockSharesAuthorized>
  <us-gaap:PreferredStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1727389" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5001_37">3697000</us-gaap:PreferredStockValue>
  <us-gaap:PreferredStockLiquidationPreferenceValue contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1727389" unitRef="iso4217_USD" decimals="0" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5001_41">4200000</us-gaap:PreferredStockLiquidationPreferenceValue>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553300x1560694" unitRef="shares" decimals="INF" id="id_10142697_1CBC7595-42F0-465C-8D31-4DF1049D9F1B_4001_6">11449463</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber>
  <galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553300x1560694" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_1FB80F50-EB14-432D-B82B-E96AF0023514_4001_6">3.48</galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageExercisePrice>
  <us-gaap:CashAndCashEquivalentsAtCarryingValue contextRef="eol_PE87402---1810-Q0001_STD_0_20161231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2001_15">15362000</us-gaap:CashAndCashEquivalentsAtCarryingValue>
  <us-gaap:CommonStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_49">50000000</us-gaap:CommonStockSharesAuthorized>
  <us-gaap:CommonStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_51">35789388</us-gaap:CommonStockSharesOutstanding>
  <us-gaap:CommonStockParOrStatedValuePerShare contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD_per_shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_48">0.001</us-gaap:CommonStockParOrStatedValuePerShare>
  <us-gaap:CommonStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_50">35789388</us-gaap:CommonStockSharesIssued>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="shares" decimals="INF" id="id_10142697_8B64E757-74DE-4210-AE6A-855267D0EFD9_1001_2">5155263</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_2A1B60B4-84A9-409D-955F-1C6DD2E32E2A_1001_2">4.11</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice>
  <us-gaap:RetainedEarningsAccumulatedDeficit contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_53">-181168000</us-gaap:RetainedEarningsAccumulatedDeficit>
  <us-gaap:Liabilities contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_13">2968000</us-gaap:Liabilities>
  <us-gaap:LiabilitiesAndStockholdersEquity contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_55">4161000</us-gaap:LiabilitiesAndStockholdersEquity>
  <us-gaap:EmployeeRelatedLiabilitiesCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_E9569066-8B58-4697-944D-B0932A34E402_1002_1">790000</us-gaap:EmployeeRelatedLiabilitiesCurrent>
  <us-gaap:AccountsPayableCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_9">608000</us-gaap:AccountsPayableCurrent>
  <us-gaap:StockholdersEquity contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_54">-530000</us-gaap:StockholdersEquity>
  <us-gaap:DividendsPayableCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_11">68000</us-gaap:DividendsPayableCurrent>
  <us-gaap:CommonStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_47">36000</us-gaap:CommonStockValue>
  <us-gaap:AdditionalPaidInCapital contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_52">173363000</us-gaap:AdditionalPaidInCapital>
  <us-gaap:AccruedProfessionalFeesCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_E9569066-8B58-4697-944D-B0932A34E402_1002_0">74000</us-gaap:AccruedProfessionalFeesCurrent>
  <us-gaap:CommitmentsAndContingencies contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" xsi:nil="true" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_14" />
  <us-gaap:LiabilitiesCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_12">2968000</us-gaap:LiabilitiesCurrent>
  <us-gaap:AccruedLiabilitiesCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_10">2292000</us-gaap:AccruedLiabilitiesCurrent>
  <us-gaap:AssetsCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_4">3819000</us-gaap:AssetsCurrent>
  <us-gaap:CashAndCashEquivalentsAtCarryingValue contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_2">3053000</us-gaap:CashAndCashEquivalentsAtCarryingValue>
  <us-gaap:Assets contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_6">4161000</us-gaap:Assets>
  <us-gaap:OtherAssetsNoncurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_5">342000</us-gaap:OtherAssetsNoncurrent>
  <us-gaap:PrepaidExpenseAndOtherAssetsCurrent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_3">766000</us-gaap:PrepaidExpenseAndOtherAssetsCurrent>
  <galt:UndesignatedCapitalStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_25">20000000</galt:UndesignatedCapitalStockSharesAuthorized>
  <galt:UndesignatedCapitalStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_26">20000000</galt:UndesignatedCapitalStockSharesOutstanding>
  <galt:UndesignatedCapitalStockParValue contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD_per_shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_24">0.01</galt:UndesignatedCapitalStockParValue>
  <galt:UndesignatedCapitalStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2_23">0</galt:UndesignatedCapitalStockValue>
  <us-gaap:TemporaryEquitySharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1553185" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1002_18">176</us-gaap:TemporaryEquitySharesOutstanding>
  <us-gaap:TemporaryEquitySharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1553185" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1002_17">176</us-gaap:TemporaryEquitySharesIssued>
  <us-gaap:TemporaryEquitySharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1553185" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1002_16">1000</us-gaap:TemporaryEquitySharesAuthorized>
  <us-gaap:TemporaryEquityCarryingAmountAttributableToParent contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1553185" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_1002_15">1723000</us-gaap:TemporaryEquityCarryingAmountAttributableToParent>
  <us-gaap:PreferredStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1668932" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2002_45">2508000</us-gaap:PreferredStockSharesOutstanding>
  <us-gaap:PreferredStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1668932" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2002_44">2508000</us-gaap:PreferredStockSharesIssued>
  <us-gaap:PreferredStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1668932" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2002_43">2508000</us-gaap:PreferredStockSharesAuthorized>
  <us-gaap:PreferredStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1668932" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_2002_42">1224000</us-gaap:PreferredStockValue>
  <us-gaap:PreferredStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1708936" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3002_30">1377500</us-gaap:PreferredStockSharesOutstanding>
  <us-gaap:PreferredStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1708936" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3002_29">1377500</us-gaap:PreferredStockSharesIssued>
  <us-gaap:PreferredStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1708936" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3002_28">1742500</us-gaap:PreferredStockSharesAuthorized>
  <us-gaap:PreferredStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1708936" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_3002_27">557000</us-gaap:PreferredStockValue>
  <us-gaap:PreferredStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1717432" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4002_35">900000</us-gaap:PreferredStockSharesOutstanding>
  <us-gaap:PreferredStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1717432" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4002_34">900000</us-gaap:PreferredStockSharesIssued>
  <us-gaap:PreferredStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1717432" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4002_33">900000</us-gaap:PreferredStockSharesAuthorized>
  <us-gaap:PreferredStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1717432" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_4002_32">1761000</us-gaap:PreferredStockValue>
  <us-gaap:PreferredStockSharesOutstanding contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1727389" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5002_40">2100000</us-gaap:PreferredStockSharesOutstanding>
  <us-gaap:PreferredStockSharesIssued contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1727389" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5002_39">2100000</us-gaap:PreferredStockSharesIssued>
  <us-gaap:PreferredStockSharesAuthorized contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1727389" unitRef="shares" decimals="INF" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5002_38">2100000</us-gaap:PreferredStockSharesAuthorized>
  <us-gaap:PreferredStockValue contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1727389" unitRef="iso4217_USD" decimals="-3" id="id_10142697_8B210B1A-9E8A-490A-AD5D-7BF57255FEAA_5002_37">3697000</us-gaap:PreferredStockValue>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553300x1560694" unitRef="shares" decimals="INF" id="id_10142697_1CBC7595-42F0-465C-8D31-4DF1049D9F1B_1001_2">13229778</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber>
  <galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553300x1560694" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_1FB80F50-EB14-432D-B82B-E96AF0023514_1001_2">3.35</galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageExercisePrice>
  <us-gaap:MinorityInterestOwnershipPercentageByNoncontrollingOwners contextRef="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553398x1558014" unitRef="pure" decimals="2" id="id_10142697_8977F936-D169-4524-92E8-6A9F54714BEE_2002_1">0.07</us-gaap:MinorityInterestOwnershipPercentageByNoncontrollingOwners>
  <us-gaap:FairValueAssumptionsExpectedVolatilityRate contextRef="eol_PE87402---1810-Q0001_STD_1_20170228_0_1558176x1744662" unitRef="pure" decimals="2" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_1001_7">0.97</us-gaap:FairValueAssumptionsExpectedVolatilityRate>
  <us-gaap:FairValueAssumptionsRiskFreeInterestRate contextRef="eol_PE87402---1810-Q0001_STD_1_20170228_0_1558176x1744662" unitRef="pure" decimals="4" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_1001_8">0.0192</us-gaap:FairValueAssumptionsRiskFreeInterestRate>
  <us-gaap:FairValueAssumptionsExpectedTerm contextRef="eol_PE87402---1810-Q0001_STD_1_20170228_0_1558176x1744662" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_1001_6">P7Y</us-gaap:FairValueAssumptionsExpectedTerm>
  <us-gaap:StockIssuedDuringPeriodSharesNewIssues contextRef="eol_PE87402---1810-Q0001_STD_1_20170228_0_1558176x1744662" unitRef="shares" decimals="INF" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_1001_0">102368</us-gaap:StockIssuedDuringPeriodSharesNewIssues>
  <us-gaap:StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants contextRef="eol_PE87402---1810-Q0001_STD_1_20170228_0_1558176x1744662" unitRef="iso4217_USD" decimals="INF" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_1001_4">101000</us-gaap:StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants>
  <us-gaap:ProceedsFromIssuanceOfPrivatePlacement contextRef="eol_PE87402---1810-Q0001_STD_1_20170228_0_1558176x1744662" unitRef="iso4217_USD" decimals="0" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_1001_1">200000</us-gaap:ProceedsFromIssuanceOfPrivatePlacement>
  <galt:ClassOfWarrantOrRightIssuedInPeriod contextRef="eol_PE87402---1810-Q0001_STD_1_20170228_0_1558176x1744662" unitRef="shares" decimals="INF" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_1001_2">76776</galt:ClassOfWarrantOrRightIssuedInPeriod>
  <us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates contextRef="eol_PE87402---1810-Q0001_STD_1186_20180331_0_1547987x1675610_1552126x1734694" unitRef="iso4217_USD" decimals="0" id="id_10142697_72BBCE3C-1421-4F58-B094-D7EE6145F09B_1001_4">123000</us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates>
  <us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates contextRef="eol_PE87402---1810-Q0001_STD_1186_20180331_0_1552126x1734694" unitRef="iso4217_USD" decimals="0" id="id_10142697_72BBCE3C-1421-4F58-B094-D7EE6145F09B_2001_2">1663000</us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates>
  <us-gaap:PaymentsToAcquireEquityMethodInvestments contextRef="eol_PE87402---1810-Q0001_STD_31_20140131_0_1552126x1734694" unitRef="iso4217_USD" decimals="0" id="id_10142697_72BBCE3C-1421-4F58-B094-D7EE6145F09B_2003_0">400000</us-gaap:PaymentsToAcquireEquityMethodInvestments>
  <galt:AccruedResearchAndDevelopmentCostsAndOther contextRef="eol_PE87402---1810-Q0001_STD_365_20171231_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_E9569066-8B58-4697-944D-B0932A34E402_2_2">1428000</galt:AccruedResearchAndDevelopmentCostsAndOther>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="shares" decimals="0" id="id_10142697_E3A7CC95-0BAE-47CA-987B-D945DEC4460F_2_3">21218186</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_10">-3863000</us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations>
  <us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="shares" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_13">33928000</us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted>
  <us-gaap:EarningsPerShareBasicAndDiluted contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_12">-0.15</us-gaap:EarningsPerShareBasicAndDiluted>
  <us-gaap:OperatingIncomeLoss contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_4">-4946000</us-gaap:OperatingIncomeLoss>
  <us-gaap:NetIncomeLoss contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_9">-4937000</us-gaap:NetIncomeLoss>
  <us-gaap:InvestmentIncomeInterest contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_6">9000</us-gaap:InvestmentIncomeInterest>
  <us-gaap:NonoperatingIncomeExpense contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_8">9000</us-gaap:NonoperatingIncomeExpense>
  <us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_11">-5209000</us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic>
  <us-gaap:IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_8">-79000</us-gaap:IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets>
  <us-gaap:DepreciationDepletionAndAmortization contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_3">1000</us-gaap:DepreciationDepletionAndAmortization>
  <us-gaap:IssuanceOfStockAndWarrantsForServicesOrClaims contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_5">14000</us-gaap:IssuanceOfStockAndWarrantsForServicesOrClaims>
  <us-gaap:PreferredStockDividendsIncomeStatementImpact contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_10">272000</us-gaap:PreferredStockDividendsIncomeStatementImpact>
  <us-gaap:ProceedsFromIssuanceOfCommonStock contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_12">2145000</us-gaap:ProceedsFromIssuanceOfCommonStock>
  <us-gaap:ShareBasedCompensation contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_4">330000</us-gaap:ShareBasedCompensation>
  <us-gaap:GeneralAndAdministrativeExpense contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_2">1174000</us-gaap:GeneralAndAdministrativeExpense>
  <us-gaap:NetCashProvidedByUsedInFinancingActivitiesContinuingOperations contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_13">2145000</us-gaap:NetCashProvidedByUsedInFinancingActivitiesContinuingOperations>
  <us-gaap:ResearchAndDevelopmentExpense contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_1">3772000</us-gaap:ResearchAndDevelopmentExpense>
  <us-gaap:CashAndCashEquivalentsPeriodIncreaseDecrease contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_14">-1718000</us-gaap:CashAndCashEquivalentsPeriodIncreaseDecrease>
  <us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_9">650000</us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities>
  <us-gaap:OperatingExpenses contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_2_3">4946000</us-gaap:OperatingExpenses>
  <galt:SupplementalDividendsOnConvertiblePreferredStock contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_2_18">339000</galt:SupplementalDividendsOnConvertiblePreferredStock>
  <us-gaap:StockIssuedDuringPeriodSharesNewIssues contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0_1550105x1587045" unitRef="shares" decimals="INF" id="id_10142697_C990EBC7-4C96-41D8-B152-935895895C9C_1002_2">1496797</us-gaap:StockIssuedDuringPeriodSharesNewIssues>
  <us-gaap:ProceedsFromIssuanceOfCommonStock contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0_1550105x1587045" unitRef="iso4217_USD" decimals="0" id="id_10142697_C990EBC7-4C96-41D8-B152-935895895C9C_1002_3">1945000</us-gaap:ProceedsFromIssuanceOfCommonStock>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0_1557484x1553312" unitRef="shares" decimals="0" id="id_10142697_E3A7CC95-0BAE-47CA-987B-D945DEC4460F_1002_2">4312282</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0_1557484x1554884" unitRef="shares" decimals="0" id="id_10142697_E3A7CC95-0BAE-47CA-987B-D945DEC4460F_2002_1">4656888</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0_1557484x1560694" unitRef="shares" decimals="0" id="id_10142697_E3A7CC95-0BAE-47CA-987B-D945DEC4460F_3002_0">12249016</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <us-gaap:ShareBasedCompensation contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0_1558588x1551807" unitRef="iso4217_USD" decimals="-3" id="id_10142697_C66DD0A6-D90B-4B9E-9035-5E332B2165A0_1002_1">164000</us-gaap:ShareBasedCompensation>
  <us-gaap:ShareBasedCompensation contextRef="eol_PE87402---1810-Q0001_STD_90_20170331_0_1558588x1556249" unitRef="iso4217_USD" decimals="-3" id="id_10142697_C66DD0A6-D90B-4B9E-9035-5E332B2165A0_2002_0">166000</us-gaap:ShareBasedCompensation>
  <us-gaap:AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_383E2E03-57E9-404B-901D-7B397649344A_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;2. Accrued Expenses&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Accrued expenses consist of the following:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="76%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="7%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="7%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;March&amp;#xA0;31,&lt;br /&gt;
 2018&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;December&amp;#xA0;31,&lt;br /&gt;
 2017&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" colspan="6" align="center"&gt;(in thousands)&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Legal and accounting fees&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;51&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;74&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Accrued compensation&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;314&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;790&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Accrued research and development costs and other&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;767&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;1,428&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Total&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;1,132&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2,292&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="shares" decimals="0" id="id_10142697_E3A7CC95-0BAE-47CA-987B-D945DEC4460F_1_3">21377008</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <us-gaap:CommitmentsAndContingenciesDisclosureTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_4D83F6AE-FEF7-411A-B5F8-A2AFB6B30CC1_1_0">&lt;div&gt;
 &lt;p style="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"&gt;
 &lt;b&gt;9. Commitments and Contingencies&lt;/b&gt;&lt;/p&gt;
 &lt;p style="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"&gt;
 &lt;b&gt;&lt;i&gt;Shareholder Class&amp;#xA0;Actions and Derivative
 Lawsuits&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"&gt;
 As previously reported, during August 2014, persons claiming to be
 Galectin shareholders filed putative shareholder derivative
 complaints seeking recovery on behalf of the Company against
 certain of the Company&amp;#x2019;s directors and officers in the United
 States District Court for the District of Nevada (the
 &amp;#x201C;Federal Action&amp;#x201D;) and in in state court in Las Vegas,
 Nevada (the &amp;#x201C;State Action&amp;#x201D; and, together with the
 Federal Action, the &amp;#x201C;Derivative Actions&amp;#x201D;). The
 complaints in the Derivative Actions alleged that certain current
 and former Galectin directors and/or officers breached fiduciary
 duties to the Company, committed waste of corporate assets, and/or
 were unjustly enriched. The complaint in the Federal Action also
 alleged claims under the federal securities laws. The Federal
 Action was dismissed with prejudice by order and judgment dated
 December&amp;#xA0;30, 2015. Although the plaintiffs in the Federal
 Action filed a notice of appeal, that appeal was subsequently
 dismissed. The State Action was dismissed with prejudice by order
 docketed on June&amp;#xA0;21, 2016. The dismissal of the State Action
 with prejudice was affirmed on appeal by the Nevada Supreme Court
 by opinion entered on April&amp;#xA0;5, 2018.&lt;/p&gt;
 &lt;p style="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"&gt;
 As also previously reported, in September 2016, the Board received
 a demand letter from one of the plaintiffs in the Federal Action
 requesting, among other things, that the Board investigate the
 conduct alleged in the complaint in the Federal Action and
 implement certain remedial measures purportedly designed to address
 the alleged conduct. Now that all of the shareholder litigation to
 which the subject matter of the demand letter relates has been
 resolved, the Board expects to complete its evaluation of the
 demand letter.&lt;/p&gt;
 &lt;p style="font-size:1px;margin-top:18px;margin-bottom:0px"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;p style="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"&gt;
 &lt;b&gt;&lt;i&gt;Other Legal Proceedings&lt;/i&gt;&lt;/b&gt;&lt;/p&gt;
 &lt;p style="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"&gt;
 The Company records accruals for such contingencies to the extent
 that the Company concludes that their occurrence is probable and
 the related damages are estimable. There are no other significant
 pending legal proceedings except as noted above.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:CommitmentsAndContingenciesDisclosureTextBlock>
  <us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_8D5154F4-050B-4288-8CDA-23C405C52D18_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;4. Stock-Based Compensation&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Following is the stock-based compensation expense related to common
 stock options, common stock, restricted common stock and common
 stock warrants:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="84%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="4%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="4%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="6" align="center"&gt;&lt;b&gt;Three&amp;#xA0;Months&amp;#xA0;Ended&lt;br /&gt;
 March&amp;#xA0;31,&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2018&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2017&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Research and development&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;534&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;166&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 General and administrative&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;653&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;164&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Total stock-based compensation expense&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;1,187&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;330&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The following table summarizes the stock option activity in the
 Company&amp;#x2019;s equity incentive plans, including &lt;font style="WHITE-SPACE: nowrap"&gt;non-plan&lt;/font&gt; grants to Company executives,
 from December&amp;#xA0;31, 2017 through&amp;#xA0;March 31, 2018:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="72%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Shares&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Weighted&amp;#xA0;Average&lt;br /&gt;
 Exercise Price&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Outstanding, December&amp;#xA0;31, 2017&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5,155,263&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4.11&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Granted&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;460,000&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5.87&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Exercised&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Options forfeited/cancelled&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Outstanding, March&amp;#xA0;31, 2018&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5,615,263&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4.26&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 As of March&amp;#xA0;31, 2018, there was $1,972,000 of unrecognized
 compensation related to 951,181 unvested options, which is expected
 to be recognized over a weighted&amp;#x2013;average period of
 approximately 0.75 years. The weighted-average grant date fair
 value for options granted during the three months ended
 March&amp;#xA0;31, 2018 was $4.57. The Company granted 460,000 stock
 options during the three months ended March&amp;#xA0;31, 2018, of which
 115,000 options vested upon grant with the remaining 345,000
 options vesting over the remainder of 2018. Approximately $526,000
 of &lt;font style="WHITE-SPACE: nowrap"&gt;non-cash,&lt;/font&gt; stock-based
 compensation expense was recorded during the three months ended
 March&amp;#xA0;31, 2018 related to the options granted during the
 quarter that vested upon the grant date.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The fair value of all other options granted is determined using the
 Black-Scholes option-pricing model. The following weighted average
 assumptions were used:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="72%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="10%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="10%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Three&lt;br /&gt;
 Months&amp;#xA0;Ended&lt;br /&gt;
 March&amp;#xA0;31,&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Three&lt;br /&gt;
 Months&amp;#xA0;Ended&lt;br /&gt;
 March&amp;#xA0;31,&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;2018&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;2017&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Risk-free interest rate&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2.18&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;%&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Expected life of the options&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5&amp;#xA0;years&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Expected volatility of the underlying stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;103&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;%&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Expected dividend rate&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;0&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;%&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock>
  <dei:DocumentFiscalPeriodFocus contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_649A4C55-C94D-4B77-8341-17BC8CBD426A_1_4">Q1</dei:DocumentFiscalPeriodFocus>
  <dei:DocumentFiscalYearFocus contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_649A4C55-C94D-4B77-8341-17BC8CBD426A_1_3">2018</dei:DocumentFiscalYearFocus>
  <dei:DocumentType contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_649A4C55-C94D-4B77-8341-17BC8CBD426A_1_0">10-Q</dei:DocumentType>
  <dei:EntityCentralIndexKey contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_E3DF0DBA-6088-4A92-BF3B-34BCC5FE8103_1_400002">0001133416</dei:EntityCentralIndexKey>
  <us-gaap:InvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_0AF7B1E9-91B5-41A0-814A-0B62F9189656_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;10. Galectin Sciences LLC&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 In January 2014, we created Galectin Sciences, LLC (the
 &amp;#x201C;LLC&amp;#x201D; or &amp;#x201C;Investee&amp;#x201D;), a collaborative joint
 venture &lt;font style="WHITE-SPACE: nowrap"&gt;co-owned&lt;/font&gt; by SBH
 Sciences, Inc. (&amp;#x201C;SBH&amp;#x201D;), to research and develop small
 organic molecule inhibitors of &lt;font style="WHITE-SPACE: nowrap"&gt;galectin-3&lt;/font&gt; for oral administration.
 The LLC was initially capitalized with a $400,000 cash investment
 to fund future research and development activities, which was
 provided by the Company, and specific &lt;font style="WHITE-SPACE: nowrap"&gt;in-process&lt;/font&gt; research and development
 (&amp;#x201C;IPR&amp;amp;D&amp;#x201D;) contributed by SBH.&amp;#xA0;The estimated
 fair value of the IPR&amp;amp;D contributed by SBH, on the date of
 contribution, was $400,000.&amp;#xA0;Initially, the Company and SBH
 each had a 50% equity ownership interest in the LLC, with neither
 party having control over the LLC.&amp;#xA0;Accordingly, from inception
 through the fourth quarter of 2014, the Company accounted for its
 investment in the LLC using the equity method of
 accounting.&amp;#xA0;Under the equity method of accounting, the
 Company&amp;#x2019;s investment was initially recorded at cost with
 subsequent adjustments to the carrying value to recognize
 additional investments in or distributions from the Investee, as
 well as the Company&amp;#x2019;s share of the Investee&amp;#x2019;s earnings,
 losses and/or changes in capital. The estimated fair value of the
 IPR&amp;amp;D contributed to the LLC was immediately expensed upon
 contribution as there was no alternative future use available at
 the point of contribution.&amp;#xA0;The operating agreement provides
 that if either party does not desire to contribute its equal share
 of funding required after the initial capitalization, then the
 other party, providing all of the funding, will have its ownership
 share increased in proportion to the total amount contributed from
 inception. In the fourth quarter of 2014, after the LLC had
 expended the $400,000 in cash, SBH decided not to contribute its
 share of the funding required. Since then, the Company has
 contributed a total of $1,663,000, including $23,000 for the three
 months ended March&amp;#xA0;31, 2018, for expenses of the LLC. Since
 the end of 2014, SBH has contributed $123,000 for expenses in the
 LLC. As of March&amp;#xA0;31, 2018, the Company&amp;#x2019;s ownership
 percentage in the LLC was 79.8%. The Company accounts for the
 interest in the LLC as a consolidated, less than wholly owned
 subsidiary. Because the LLC&amp;#x2019;s equity is immaterial, the value
 of the &lt;font style="WHITE-SPACE: nowrap"&gt;non-controlling&lt;/font&gt;
 interest is also deemed to be immaterial.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:InvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTextBlock>
  <us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_10">-3516000</us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations>
  <us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_8E51ABA2-26C1-4F4C-AFEC-BEAFACEDBAF9_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 Dilutive shares which could exist pursuant to the exercise of
 outstanding stock instruments and which were not included in the
 calculation because their affect would have been anti-dilutive are
 as follows:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="70%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="5%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="5%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;March&amp;#xA0;31,&amp;#xA0;2018&lt;br /&gt;
 (shares)&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;March&amp;#xA0;31,&amp;#xA0;2017&lt;br /&gt;
 (shares)&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Warrants to purchase shares of common stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;11,449,463&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;12,249,016&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Options to purchase shares of common stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5,615,263&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,656,888&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Shares of common stock issuable upon conversion of preferred
 stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,312,282&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,312,282&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;21,377,008&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;21,218,186&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock>
  <us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD_per_shares" decimals="0" id="id_10142697_2A1B60B4-84A9-409D-955F-1C6DD2E32E2A_5001_4">0</us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice>
  <us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1 contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_49459F1E-A1A3-4CE7-AAE4-25B0EC00F96A_1_1">P5Y</us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1>
  <dei:TradingSymbol contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_E3DF0DBA-6088-4A92-BF3B-34BCC5FE8103_1_400000">GALT</dei:TradingSymbol>
  <dei:AmendmentFlag contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_649A4C55-C94D-4B77-8341-17BC8CBD426A_1_1">false</dei:AmendmentFlag>
  <us-gaap:ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_7DE213CE-E5AA-4EEA-8698-9B7256E517C2_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Following is the stock-based compensation expense related to common
 stock options, common stock, restricted common stock and common
 stock warrants:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="84%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="4%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="4%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="6" align="center"&gt;&lt;b&gt;Three&amp;#xA0;Months&amp;#xA0;Ended&lt;br /&gt;
 March&amp;#xA0;31,&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2018&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;&lt;b&gt;2017&lt;/b&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Research and development&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;534&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;166&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 General and administrative&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;653&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;164&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Total stock-based compensation expense&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;1,187&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;330&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock>
  <us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD_per_shares" decimals="0" id="id_10142697_2A1B60B4-84A9-409D-955F-1C6DD2E32E2A_5001_5">0</us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice>
  <us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_2A1B60B4-84A9-409D-955F-1C6DD2E32E2A_5001_3">5.87</us-gaap:ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="pure" decimals="2" id="id_10142697_49459F1E-A1A3-4CE7-AAE4-25B0EC00F96A_1_3">0.00</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="pure" decimals="4" id="id_10142697_49459F1E-A1A3-4CE7-AAE4-25B0EC00F96A_1_0">0.0218</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B64E757-74DE-4210-AE6A-855267D0EFD9_5001_5">0</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_25289D46-C2CD-492B-A0F0-4333D49920A3_1_3">4.57</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue>
  <us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="shares" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_13">37284000</us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted>
  <us-gaap:BasisOfAccounting contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_8FEE393C-1463-43C1-87D1-608D836B922A_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt"&gt;
 &lt;b&gt;1. Basis of Presentation&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Galectin Therapeutics Inc. (the &amp;#x201C;Company&amp;#x201D;) is a
 clinical stage biopharmaceutical company that is applying its
 leadership in galectin science and drug development to create new
 therapies for fibrotic disease, skin diseases and cancer. These
 candidates are based on the Company&amp;#x2019;s targeting of galectin
 proteins which are key mediators of biologic and pathologic
 function. These compounds also may have application for drugs to
 treat other diseases and chronic health conditions.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The unaudited condensed consolidated financial statements as
 reported in this Quarterly Report on Form &lt;font style="WHITE-SPACE: nowrap"&gt;10-Q&lt;/font&gt; reflect all adjustments which
 are, in the opinion of management, necessary to present fairly the
 financial position of the Company as of March&amp;#xA0;31, 2018 and the
 results of its operations for the three months ended March&amp;#xA0;31,
 2018 and 2017 and its cash flows for the three months ended
 March&amp;#xA0;31, 2018 and 2017. All adjustments made to the interim
 financial statements include all those of a normal and recurring
 nature. Amounts presented in the condensed consolidated balance
 sheet as of December&amp;#xA0;31, 2017 are derived from the
 Company&amp;#x2019;s audited consolidated financial statements as of
 that date, but do not include all of the information and footnotes
 required by accounting principles generally accepted in the United
 States of America for complete financial statements. The Company
 considers events or transactions that occur after the balance sheet
 date but before the financial statements are issued to provide
 additional evidence relative to certain estimates or to identify
 matters that require additional disclosure. Subsequent events have
 been evaluated through the date these financial statements are
 available to be issued. The results for interim periods are not
 necessarily indicative of results that may be expected for any
 other interim period or for the full year. The unaudited condensed
 consolidated financial statements of the Company should be read in
 conjunction with its Annual Report on Form &lt;font style="WHITE-SPACE: nowrap"&gt;10-K&lt;/font&gt; for the year ended
 December&amp;#xA0;31, 2017.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company has operated at a loss since its inception and has had
 no significant revenues. The Company anticipates that losses will
 continue for the foreseeable future. At March&amp;#xA0;31, 2018, the
 Company had $4.0&amp;#xA0;million of unrestricted cash and cash
 equivalents available to fund future operations. The Company
 believes there is sufficient cash, including availability of the
 line of credit (discussed in Note 3 below), to fund currently
 planned operations at least through March&amp;#xA0;31, 2019. The
 Company&amp;#x2019;s ability to fund operations after its current cash
 resources are exhausted depends on its ability to obtain additional
 financing or achieve profitable operations, as to which no
 assurances can be given. Accordingly, based on the forecasts and
 estimates underlying the Company&amp;#x2019;s current operating plan,
 the financial statements do not currently include any adjustments
 that might be necessary if the Company is unable to continue as a
 going concern.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The Company was founded in July 2000, was incorporated in the State
 of Nevada in January 2001 under the name &lt;font style="WHITE-SPACE: nowrap"&gt;&amp;#x201C;Pro-Pharmaceuticals,&lt;/font&gt;
 Inc.,&amp;#x201D; and changed its name to &amp;#x201C;Galectin Therapeutics
 Inc.&amp;#x201D; on May&amp;#xA0;26, 2011.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:BasisOfAccounting>
  <dei:CurrentFiscalYearEndDate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_E3DF0DBA-6088-4A92-BF3B-34BCC5FE8103_1_400003">--12-31</dei:CurrentFiscalYearEndDate>
  <us-gaap:DebtDisclosureTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_85D648F7-60AC-4205-826C-09A2B1673109_1_0">&lt;div&gt;
 &lt;p style="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"&gt;
 &lt;b&gt;3. Line of Credit&lt;/b&gt;&lt;/p&gt;
 &lt;p style="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"&gt;
 On December&amp;#xA0;19, 2017, the Company entered into a
 $10&amp;#xA0;million Line of Credit arrangement with Richard E.
 Uihlein, a director and shareholder who has an approximate 7%
 ownership interest in the Company on a fully-diluted basis at
 December&amp;#xA0;31, 2017. Borrowings may be made by the Company
 through December&amp;#xA0;31, 2018. Borrowings bear interest at the
 Applicable Federal Rate for short term loans published by the
 Internal Revenue Service (1.51% on December&amp;#xA0;19, 2017). All
 borrowings and interest are due on December&amp;#xA0;31, 2019 but may
 be prepaid without penalty. In connection with the Line of Credit
 agreement, the Company issued to Mr.&amp;#xA0;Uihlein warrants to
 purchase 1&amp;#xA0;million shares of the Company&amp;#x2019;s common stock
 for $5 per share. Half of the warrants vested at closing of the
 Line of Credit and the other half vest ratably with borrowings
 under the agreement. There have been no borrowings under the Line
 of Credit through March&amp;#xA0;31, 2018.&lt;/p&gt;
 &lt;p style="font-size:1px;margin-top:6px;margin-bottom:0px"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;p style="margin-top:0pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"&gt;
 The fair value of the 500,000 warrants vested at closing was
 $696,000 at the date of issuance based on the following
 assumptions: an expected life of 7 years, volatility of 98%, risk
 free interest rate of 2.05% and zero dividends. The fair value of
 the vested warrants was recorded in other current assets and other
 assets &lt;font style="white-space:nowrap"&gt;(non-current)&lt;/font&gt; as a
 deferred financing cost and will be amortized on a straight-line
 basis from December&amp;#xA0;19, 2017 through December&amp;#xA0;31, 2019.
 Amortization for the three months ended March&amp;#xA0;31, 2018 of
 $84,000 was recorded as interest expense. The fair value of
 warrants that vest in the future based on borrowings will be
 computed when those borrowings occur and amortized over the
 remaining period through December&amp;#xA0;31, 2019.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:DebtDisclosureTextBlock>
  <dei:DocumentPeriodEndDate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_649A4C55-C94D-4B77-8341-17BC8CBD426A_1_2">2018-03-31</dei:DocumentPeriodEndDate>
  <dei:EntityFilerCategory contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_E3DF0DBA-6088-4A92-BF3B-34BCC5FE8103_1_400004">Smaller Reporting Company</dei:EntityFilerCategory>
  <us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_62414029-D639-4A46-9BCE-2F1AE3C69447_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The following table summarizes the stock option activity in the
 Company&amp;#x2019;s equity incentive plans, including &lt;font style="WHITE-SPACE: nowrap"&gt;non-plan&lt;/font&gt; grants to Company executives,
 from December&amp;#xA0;31, 2017 through&amp;#xA0;March 31, 2018:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="72%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="8%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Shares&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Weighted&amp;#xA0;Average&lt;br /&gt;
 Exercise Price&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Outstanding, December&amp;#xA0;31, 2017&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5,155,263&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4.11&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Granted&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;460,000&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5.87&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Exercised&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Options forfeited/cancelled&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Outstanding, March&amp;#xA0;31, 2018&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5,615,263&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4.26&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock>
  <us-gaap:ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_F5E2BFB5-9199-42DA-93EA-2EFE119938EC_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 The fair value of all other options granted is determined using the
 Black-Scholes option-pricing model. The following weighted average
 assumptions were used:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="72%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="10%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="10%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Three&lt;br /&gt;
 Months&amp;#xA0;Ended&lt;br /&gt;
 March&amp;#xA0;31,&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Three&lt;br /&gt;
 Months&amp;#xA0;Ended&lt;br /&gt;
 March&amp;#xA0;31,&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;2018&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;2017&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Risk-free interest rate&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2.18&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;%&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Expected life of the options&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5&amp;#xA0;years&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Expected volatility of the underlying stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;103&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;%&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Expected dividend rate&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;0&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;%&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock>
  <us-gaap:ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_8AE9A22A-71CF-4F90-9BCE-39AB42E3E50E_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The following table summarizes the common stock warrant activity
 from December&amp;#xA0;31, 2017 through March&amp;#xA0;31, 2018:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="69%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="9%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="9%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Shares&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Weighted&amp;#xA0;Average&lt;br /&gt;
 Exercise Price&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Outstanding, December&amp;#xA0;31, 2017&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;13,229,778&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;3.35&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Granted&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;163&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5.23&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Exercised&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;(1,780,478&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;)&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2.50&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Forfeited/cancelled&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Outstanding, March&amp;#xA0;31, 2018&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;11,449,463&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;3.48&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B64E757-74DE-4210-AE6A-855267D0EFD9_5001_3">460000</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross>
  <us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_25289D46-C2CD-492B-A0F0-4333D49920A3_1_5">115000</us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares>
  <us-gaap:StockholdersEquityNoteDisclosureTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_07C2179C-6184-4DC5-B5CE-5AB330B0DF22_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;8. Common Stock&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt"&gt;
 &lt;i&gt;2014 At Market Issuance of Common Stock&lt;/i&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 On March&amp;#xA0;30, 2014, the Company entered into an At Market
 Issuance Sales Agreement (the &amp;#x201C;2014 At Market
 Agreement&amp;#x201D;) with a sales agent under which the Company may
 issue and sell shares of its common stock having an aggregate
 offering price of up to $30.0&amp;#xA0;million from time to time
 through the sales agent. Sales of the Company&amp;#x2019;s common stock
 through the sales agent, if any, will be made by any method that is
 deemed an &amp;#x201C;at the market&amp;#x201D; offering as defined by the
 U.S. Securities and Exchange Commission. The Company will pay to
 the sales agent a commission rate equal to 3.0% of the gross
 proceeds from the sale of any shares of common stock sold through
 the sales agent under the 2014 At Market Agreement. In three months
 ended March&amp;#xA0;31, 2017, the Company issued 1,496,797 shares of
 common stock for net proceeds of approximately $1,945,000 under the
 2014 At Market Agreement. The 2014 At Market Agreement expired in
 March 2017.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0px; FONT-SIZE: 1px; MARGIN-TOP: 18px"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 0pt"&gt;
 &lt;i&gt;2017 At Market Issuance of Common Stock&lt;/i&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 On May&amp;#xA0;19, 2017, the Company entered into an At Market
 Issuance Sales Agreement (the &amp;#x201C;2017 At Market
 Agreement&amp;#x201D;) with a sales agent under which the Company may
 issue and sell shares of its common stock having an aggregate
 offering price of up to $30.0&amp;#xA0;million from time to time
 through the sales agent. Sales of the Company&amp;#x2019;s common stock
 through the sales agent, if any, will be made by any method that is
 deemed an &amp;#x201C;at the market&amp;#x201D; offering as defined by the
 U.S. Securities and Exchange Commission. The Company will pay to
 the sales agent a commission rate equal to 3.0% of the gross
 proceeds from the sale of any shares of common stock sold through
 the sales agent under the 2017 At Market Agreement. During the
 three months ended March&amp;#xA0;31, 2018, there were no issuances of
 common stock under the 2017 At Market Agreement.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;i&gt;2017 Private Placement&lt;/i&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 On February&amp;#xA0;28, 2017, the Company closed a transaction with
 five individual investors through a private placement of common
 stock and warrants. In total, the Company issued 102,368 shares of
 common stock for proceeds of $200,000. The Company also issued, to
 the five investors, warrants to purchase 76,776 shares of common
 stock at $5.00 per share. The warrants have an expiration date of
 February&amp;#xA0;28, 2024. The exercise price of each warrant is
 adjustable in the event of a stock split or stock combination,
 capital reorganization, merger or similar event. The warrants were
 valued at approximately $101,000 as of the date of issuance, using
 the closing price of $1.86, a life of 7 years, a volatility of 97%
 and a risk free interest rate of 1.92%. Based upon the
 Company&amp;#x2019;s analysis of the criteria contained in ASC Topic
 &lt;font style="WHITE-SPACE: nowrap"&gt;815-40,&lt;/font&gt; &amp;#x201C;Derivatives
 and Hedging &amp;#x2014; Contracts in Entity&amp;#x2019;s Own Equity&amp;#x201D;
 the Company has determined that warrants issued in connection with
 this financing transaction were not derivative liabilities and
 therefore, were recorded as additional &lt;font style="WHITE-SPACE: nowrap"&gt;paid-in&lt;/font&gt; capital.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;i&gt;Other&lt;/i&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 In 2018, the Company entered an agreement with a vendor whereby the
 Company will issue common stock to vendor in lieu of paying in cash
 in amount up to $100,000 for the year. For the three months ended
 March&amp;#xA0;31, 2018, the Company has issued 1,629 shares of common
 stock and 163 warrants to purchase shares of common stock pursuant
 to this agreement and the value of such shares has been recorded as
 research and development expense.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 For the three months ended March&amp;#xA0;31, 2018, the Company has
 issued a total of 74,476 shares of common stock for dividends on
 Series&amp;#xA0;A, Series&amp;#xA0;B and Series&amp;#xA0;C Preferred Stock.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:StockholdersEquityNoteDisclosureTextBlock>
  <us-gaap:StockIssuedDuringPeriodSharesStockOptionsExercised contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="shares" decimals="INF" id="id_10142697_8B64E757-74DE-4210-AE6A-855267D0EFD9_5001_4">0</us-gaap:StockIssuedDuringPeriodSharesStockOptionsExercised>
  <us-gaap:EarningsPerShareBasicAndDiluted contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_12">-0.12</us-gaap:EarningsPerShareBasicAndDiluted>
  <us-gaap:EarningsPerShareTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_A2177356-2DE7-4094-8CD7-C4C01E7835CD_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;7. Loss Per Share&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Basic net loss per common share is computed by dividing the net
 loss available to common stockholders by the weighted average
 number of common shares outstanding during the period. Diluted net
 loss per common share is computed by dividing the net loss
 available to common stockholders by the weighted average number of
 common shares and other potential common shares then outstanding.
 Potential common shares consist of common shares issuable upon the
 assumed exercise of &lt;font style="WHITE-SPACE: nowrap"&gt;&lt;font style="WHITE-SPACE: nowrap"&gt;in-the-money&lt;/font&gt;&lt;/font&gt; stock options and
 warrants and potential common shares related to the conversion of
 the preferred stock. The computation of diluted net loss per share
 does not assume the issuance of common shares that have an
 anti-dilutive effect on net loss per share.&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 12pt; TEXT-INDENT: 4%"&gt;
 Dilutive shares which could exist pursuant to the exercise of
 outstanding stock instruments and which were not included in the
 calculation because their affect would have been anti-dilutive are
 as follows:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="70%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="5%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="5%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;March&amp;#xA0;31,&amp;#xA0;2018&lt;br /&gt;
 (shares)&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;March&amp;#xA0;31,&amp;#xA0;2017&lt;br /&gt;
 (shares)&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Warrants to purchase shares of common stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;11,449,463&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;12,249,016&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Options to purchase shares of common stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5,615,263&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,656,888&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Shares of common stock issuable upon conversion of preferred
 stock&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,312,282&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;4,312,282&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;21,377,008&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;21,218,186&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:EarningsPerShareTextBlock>
  <us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_25289D46-C2CD-492B-A0F0-4333D49920A3_1_2">P9M</us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1>
  <dei:EntityRegistrantName contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_E3DF0DBA-6088-4A92-BF3B-34BCC5FE8103_1_400001">GALECTIN THERAPEUTICS INC</dei:EntityRegistrantName>
  <us-gaap:FairValueDisclosuresTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_9AEDFD29-F503-4E26-9BA7-03136898A35B_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 18pt"&gt;
 &lt;b&gt;6. Fair Value of Financial Instruments&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The Company has certain financial assets and liabilities recorded
 at fair value. Fair values determined by Level&amp;#xA0;1 inputs
 utilize observable data such as quoted prices in active markets.
 Fair values determined by Level&amp;#xA0;2 inputs utilize data points
 other than quoted prices in active markets that are observable
 either directly or indirectly. Fair values determined by
 Level&amp;#xA0;3 inputs utilize unobservable data points in which there
 is little or no market data, which require the reporting entity to
 develop its own assumptions. The carrying amounts reflected in the
 consolidated balance sheets for cash equivalents, accounts payable
 and accrued expenses approximate their carrying value due to their
 short-term nature. There were no level 2 or level 3 assets or
 liabilities at March&amp;#xA0;31, 2018 or December&amp;#xA0;31, 2017.&lt;/p&gt;
 &lt;/div&gt;</us-gaap:FairValueDisclosuresTextBlock>
  <us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_EA497792-3BF3-4B92-984F-7D0924BC37D2_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 Accrued expenses consist of the following:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="76%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="7%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="7%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;March&amp;#xA0;31,&lt;br /&gt;
 2018&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;December&amp;#xA0;31,&lt;br /&gt;
 2017&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" colspan="6" align="center"&gt;(in thousands)&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Legal and accounting fees&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;51&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;74&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Accrued compensation&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;314&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;790&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Accrued research and development costs and other&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;767&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;1,428&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Total&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;1,132&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2,292&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="pure" decimals="2" id="id_10142697_49459F1E-A1A3-4CE7-AAE4-25B0EC00F96A_1_2">1.03</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate>
  <us-gaap:OperatingIncomeLoss contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_4">-4178000</us-gaap:OperatingIncomeLoss>
  <us-gaap:NetIncomeLoss contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_9">-4258000</us-gaap:NetIncomeLoss>
  <us-gaap:InvestmentIncomeInterest contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_6">4000</us-gaap:InvestmentIncomeInterest>
  <us-gaap:NonoperatingIncomeExpense contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_8">-80000</us-gaap:NonoperatingIncomeExpense>
  <us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_11">-4543000</us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic>
  <us-gaap:IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_8">-81000</us-gaap:IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets>
  <us-gaap:InterestExpense contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_7">84000</us-gaap:InterestExpense>
  <us-gaap:IssuanceOfStockAndWarrantsForServicesOrClaims contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_5">7000</us-gaap:IssuanceOfStockAndWarrantsForServicesOrClaims>
  <us-gaap:PreferredStockDividendsIncomeStatementImpact contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_10">285000</us-gaap:PreferredStockDividendsIncomeStatementImpact>
  <us-gaap:ProceedsFromIssuanceOfCommonStock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_12">4451000</us-gaap:ProceedsFromIssuanceOfCommonStock>
  <us-gaap:ShareBasedCompensation contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_4">1187000</us-gaap:ShareBasedCompensation>
  <us-gaap:PaidInKindInterest contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_6">84000</us-gaap:PaidInKindInterest>
  <us-gaap:GeneralAndAdministrativeExpense contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_2">1880000</us-gaap:GeneralAndAdministrativeExpense>
  <us-gaap:InterestExpenseDebt contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="0" id="id_10142697_410AC137-1A6D-4639-8393-AC1CAB7918EC_1_6">84000</us-gaap:InterestExpenseDebt>
  <us-gaap:NetCashProvidedByUsedInFinancingActivitiesContinuingOperations contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_13">4451000</us-gaap:NetCashProvidedByUsedInFinancingActivitiesContinuingOperations>
  <us-gaap:ResearchAndDevelopmentExpense contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_1">2298000</us-gaap:ResearchAndDevelopmentExpense>
  <us-gaap:CashAndCashEquivalentsPeriodIncreaseDecrease contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_14">935000</us-gaap:CashAndCashEquivalentsPeriodIncreaseDecrease>
  <us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_9">-617000</us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities>
  <us-gaap:OperatingExpenses contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_9E4382BB-4921-4DA8-8799-F9063F4321AF_1_3">4178000</us-gaap:OperatingExpenses>
  <galt:StockWarrantsTextBlock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" id="id_10142697_5D358132-57A0-4893-80FD-F70E436D2469_1_0">&lt;div&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 0pt"&gt;
 &lt;b&gt;5. Common Stock Warrants&lt;/b&gt;&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-TOP: 6pt; TEXT-INDENT: 4%"&gt;
 The following table summarizes the common stock warrant activity
 from December&amp;#xA0;31, 2017 through March&amp;#xA0;31, 2018:&lt;/p&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 12pt; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;table style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; BORDER-COLLAPSE: collapse" cellspacing="0" cellpadding="0" width="76%" align="center" border="0"&gt;
 &lt;tr&gt;
 &lt;td width="69%"&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="9%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td valign="bottom" width="9%"&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;td&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Shares&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td style="BORDER-BOTTOM: #000000 1pt solid" valign="bottom" colspan="2" align="center"&gt;Weighted&amp;#xA0;Average&lt;br /&gt;
 Exercise Price&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Outstanding, December&amp;#xA0;31, 2017&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;13,229,778&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;3.35&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Granted&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;163&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;5.23&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Exercised&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;(1,780,478&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;)&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;2.50&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 3em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Forfeited/cancelled&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap" align="right"&gt;
 &amp;#x2014;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 1px solid; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; PAGE-BREAK-INSIDE: avoid" bgcolor="#CCEEFF"&gt;
 &lt;td valign="top"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; MARGIN-LEFT: 1em; MARGIN-TOP: 0pt; TEXT-INDENT: -1em"&gt;
 Outstanding, March&amp;#xA0;31, 2018&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;11,449,463&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;$&lt;/td&gt;
 &lt;td valign="bottom" align="right"&gt;3.48&lt;/td&gt;
 &lt;td valign="bottom" nowrap="nowrap"&gt;&amp;#xA0;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;tr style="FONT-SIZE: 1px"&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td valign="bottom"&gt;
 &lt;p style="MARGIN-BOTTOM: 0pt; BORDER-TOP: #000000 3px double; MARGIN-TOP: 0pt"&gt;
 &amp;#xA0;&lt;/p&gt;
 &lt;/td&gt;
 &lt;td&gt;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&amp;#xA0;&amp;#xA0;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;td valign="bottom"&gt;&lt;/td&gt;
 &lt;/tr&gt;
 &lt;/table&gt;
 &lt;/div&gt;</galt:StockWarrantsTextBlock>
  <galt:AccruedResearchAndDevelopmentCostsAndOther contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_E9569066-8B58-4697-944D-B0932A34E402_1_2">767000</galt:AccruedResearchAndDevelopmentCostsAndOther>
  <galt:IssuanceOfWarrantsValue contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="0" id="id_10142697_410AC137-1A6D-4639-8393-AC1CAB7918EC_1_1">696000</galt:IssuanceOfWarrantsValue>
  <galt:SupplementalDividendsOnConvertiblePreferredStock contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0" unitRef="iso4217_USD" decimals="-3" id="id_10142697_B4144186-F6F4-4F9C-85DC-D284002C586E_1_18">353000</galt:SupplementalDividendsOnConvertiblePreferredStock>
  <us-gaap:ShareBasedCompensation contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1547686x1554884" unitRef="iso4217_USD" decimals="0" id="id_10142697_25289D46-C2CD-492B-A0F0-4333D49920A3_1001_7">526000</us-gaap:ShareBasedCompensation>
  <us-gaap:SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1547987x1675610_1552126x1734694" unitRef="pure" decimals="3" id="id_10142697_72BBCE3C-1421-4F58-B094-D7EE6145F09B_1002_5">0.798</us-gaap:SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions>
  <galt:ClassOfWarrantOrRightIssuedInPeriod contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1550105x1727852" unitRef="shares" decimals="INF" id="id_10142697_888DA2D2-DC4A-48CC-BD50-963A56B7D31D_1001_3">163</galt:ClassOfWarrantOrRightIssuedInPeriod>
  <us-gaap:CommonStockDividendsShares contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1550105x1727852_1553300x1774499" unitRef="shares" decimals="INF" id="id_10142697_888DA2D2-DC4A-48CC-BD50-963A56B7D31D_2001_2">74476</us-gaap:CommonStockDividendsShares>
  <us-gaap:StockIssuedDuringPeriodSharesNewIssues contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1550105x1766096" unitRef="shares" decimals="INF" id="id_10142697_B51FF437-EB1C-45B5-BC48-009D5815BEB3_1002_2">0</us-gaap:StockIssuedDuringPeriodSharesNewIssues>
  <us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1552126x1734694" unitRef="iso4217_USD" decimals="0" id="id_10142697_72BBCE3C-1421-4F58-B094-D7EE6145F09B_2002_2">23000</us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates>
  <us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1 contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" id="id_10142697_410AC137-1A6D-4639-8393-AC1CAB7918EC_1001_2">P7Y</us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="shares" decimals="INF" id="id_10142697_1CBC7595-42F0-465C-8D31-4DF1049D9F1B_5001_5">0</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="pure" decimals="2" id="id_10142697_410AC137-1A6D-4639-8393-AC1CAB7918EC_1001_4">0.00</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="pure" decimals="4" id="id_10142697_410AC137-1A6D-4639-8393-AC1CAB7918EC_1001_5">0.0205</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="pure" decimals="2" id="id_10142697_410AC137-1A6D-4639-8393-AC1CAB7918EC_1001_3">0.98</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="shares" decimals="INF" id="id_10142697_1CBC7595-42F0-465C-8D31-4DF1049D9F1B_5001_4">1780478</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised>
  <us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="shares" decimals="INF" id="id_10142697_1CBC7595-42F0-465C-8D31-4DF1049D9F1B_5001_3">163</us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod>
  <galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresInPeriodWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="iso4217_USD_per_shares" decimals="0" id="id_10142697_1FB80F50-EB14-432D-B82B-E96AF0023514_5001_5">0</galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresInPeriodWeightedAverageExercisePrice>
  <galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisesInPeriodWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_1FB80F50-EB14-432D-B82B-E96AF0023514_5001_4">2.50</galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisesInPeriodWeightedAverageExercisePrice>
  <galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageExercisePrice contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694" unitRef="iso4217_USD_per_shares" decimals="2" id="id_10142697_1FB80F50-EB14-432D-B82B-E96AF0023514_5001_3">5.23</galt:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageExercisePrice>
  <us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1556602x1595860" unitRef="shares" decimals="INF" id="id_10142697_25289D46-C2CD-492B-A0F0-4333D49920A3_2001_6">345000</us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1557484x1553312" unitRef="shares" decimals="0" id="id_10142697_E3A7CC95-0BAE-47CA-987B-D945DEC4460F_1001_2">4312282</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1557484x1554884" unitRef="shares" decimals="0" id="id_10142697_E3A7CC95-0BAE-47CA-987B-D945DEC4460F_2001_1">5615263</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1557484x1560694" unitRef="shares" decimals="0" id="id_10142697_E3A7CC95-0BAE-47CA-987B-D945DEC4460F_3001_0">11449463</us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount>
  <galt:WarrantExpirationDate contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1558176x1744662" id="id_10142697_52296834-E1F2-4A89-8699-D229E898ACDA_1002_9">2024-02-28</galt:WarrantExpirationDate>
  <us-gaap:ShareBasedCompensation contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1558588x1551807" unitRef="iso4217_USD" decimals="-3" id="id_10142697_C66DD0A6-D90B-4B9E-9035-5E332B2165A0_1001_1">653000</us-gaap:ShareBasedCompensation>
  <us-gaap:ShareBasedCompensation contextRef="eol_PE87402---1810-Q0001_STD_90_20180331_0_1558588x1556249" unitRef="iso4217_USD" decimals="-3" id="id_10142697_C66DD0A6-D90B-4B9E-9035-5E332B2165A0_2001_0">534000</us-gaap:ShareBasedCompensation>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1558588x1556249">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:IncomeStatementLocationAxis">us-gaap:ResearchAndDevelopmentExpenseMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1558588x1551807">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:IncomeStatementLocationAxis">us-gaap:GeneralAndAdministrativeExpenseMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1558176x1744662">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:EquityInterestIssuedOrIssuableByTypeAxis">galt:PrivatePlacementTwentySeventeenMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1557484x1560694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis">us-gaap:WarrantMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1557484x1554884">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis">us-gaap:EmployeeStockOptionMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1557484x1553312">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis">us-gaap:StockCompensationPlanMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1556602x1595860">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementScenarioAxis">galt:RemainderOfCurrentYearMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1553300x1560694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementEquityComponentsAxis">us-gaap:WarrantMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1552126x1734694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="dei:LegalEntityAxis">galt:GalectinSciencesLlcMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1550105x1766096">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:TypeOfArrangementAxis">galt:TwoThousandSeventeenAtMarketSalesAgreementMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1550105x1727852_1553300x1774499">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementEquityComponentsAxis">galt:SeriesAndPreferredStockMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:TypeOfArrangementAxis">galt:OtherAgreementsMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1550105x1727852">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:TypeOfArrangementAxis">galt:OtherAgreementsMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1547987x1675610_1552126x1734694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="dei:LegalEntityAxis">galt:GalectinSciencesLlcMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:CounterpartyNameAxis">galt:SbhSciencesIncMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0_1547686x1554884">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:AwardTypeAxis">us-gaap:EmployeeStockOptionMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20180331_0">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
    </entity>
    <period>
      <startDate>2018-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20170331_0_1558588x1556249">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:IncomeStatementLocationAxis">us-gaap:ResearchAndDevelopmentExpenseMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2017-01-01</startDate>
      <endDate>2017-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20170331_0_1558588x1551807">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:IncomeStatementLocationAxis">us-gaap:GeneralAndAdministrativeExpenseMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2017-01-01</startDate>
      <endDate>2017-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20170331_0_1557484x1560694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis">us-gaap:WarrantMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2017-01-01</startDate>
      <endDate>2017-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20170331_0_1557484x1554884">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis">us-gaap:EmployeeStockOptionMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2017-01-01</startDate>
      <endDate>2017-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20170331_0_1557484x1553312">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis">us-gaap:StockCompensationPlanMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2017-01-01</startDate>
      <endDate>2017-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20170331_0_1550105x1587045">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:TypeOfArrangementAxis">galt:TwoThousandFourteenAtMarketSalesAgreementMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2017-01-01</startDate>
      <endDate>2017-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_90_20170331_0">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
    </entity>
    <period>
      <startDate>2017-01-01</startDate>
      <endDate>2017-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_365_20171231_0">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
    </entity>
    <period>
      <startDate>2017-01-01</startDate>
      <endDate>2017-12-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_31_20140131_0_1552126x1734694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="dei:LegalEntityAxis">galt:GalectinSciencesLlcMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2014-01-01</startDate>
      <endDate>2014-01-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_1186_20180331_0_1552126x1734694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="dei:LegalEntityAxis">galt:GalectinSciencesLlcMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2015-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_1186_20180331_0_1547987x1675610_1552126x1734694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="dei:LegalEntityAxis">galt:GalectinSciencesLlcMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:CounterpartyNameAxis">galt:SbhSciencesIncMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2015-01-01</startDate>
      <endDate>2018-03-31</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_1_20170228_0_1558176x1744662">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:EquityInterestIssuedOrIssuableByTypeAxis">galt:PrivatePlacementTwentySeventeenMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <startDate>2017-02-28</startDate>
      <endDate>2017-02-28</endDate>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553398x1558014">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:TitleOfIndividualAxis">us-gaap:DirectorMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553300x1560694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementEquityComponentsAxis">us-gaap:WarrantMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1727389">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">galt:SeriesBTwoConvertiblePreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1717432">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">galt:SeriesBOneConvertiblePreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1708936">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">galt:SeriesAConvertiblePreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1668932">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">galt:SeriesBThreeConvertiblePreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171231_0_1553299x1553185">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">us-gaap:SeriesCPreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171231_0">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
    </entity>
    <period>
      <instant>2017-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20161231_0">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
    </entity>
    <period>
      <instant>2016-12-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553300x1560694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementEquityComponentsAxis">us-gaap:WarrantMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1727389">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">galt:SeriesBTwoConvertiblePreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1717432">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">galt:SeriesBOneConvertiblePreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1708936">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">galt:SeriesAConvertiblePreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1668932">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">galt:SeriesBThreeConvertiblePreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1553299x1553185">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:StatementClassOfStockAxis">us-gaap:SeriesCPreferredStockMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1552126x1734694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="dei:LegalEntityAxis">galt:GalectinSciencesLlcMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1549585x1749940_1550105x1727852_1559480x1552364">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:RangeAxis">us-gaap:MaximumMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:RelatedPartyTransactionsByRelatedPartyAxis">galt:VendorMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:TypeOfArrangementAxis">galt:OtherAgreementsMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1549585x1749940_1550105x1727852">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:RelatedPartyTransactionsByRelatedPartyAxis">galt:VendorMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:TypeOfArrangementAxis">galt:OtherAgreementsMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0_1547993x1728624_1553398x1558014">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:CreditFacilityAxis">galt:UnsecuredLineOfCreditMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:TitleOfIndividualAxis">us-gaap:DirectorMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180331_0">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
    </entity>
    <period>
      <instant>2018-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20170331_0">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
    </entity>
    <period>
      <instant>2017-03-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20140330_0_1550105x1587045">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:TypeOfArrangementAxis">galt:TwoThousandFourteenAtMarketSalesAgreementMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2014-03-30</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20180508_0">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
    </entity>
    <period>
      <instant>2018-05-08</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20171219_0_1547993x1728624_1553398x1558014">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:CreditFacilityAxis">galt:UnsecuredLineOfCreditMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:TitleOfIndividualAxis">us-gaap:DirectorMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-12-19</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20170519_0_1550105x1766096">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:TypeOfArrangementAxis">galt:TwoThousandSeventeenAtMarketSalesAgreementMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-05-19</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20170228_0_1558176x1744662">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="us-gaap:EquityInterestIssuedOrIssuableByTypeAxis">galt:PrivatePlacementTwentySeventeenMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2017-02-28</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20140131_0_1552126x1734694">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="dei:LegalEntityAxis">galt:GalectinSciencesLlcMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2014-01-31</instant>
    </period>
  </context>
  <context id="eol_PE87402---1810-Q0001_STD_0_20140131_0_1547987x1675610_1552126x1734694_1555137x1558637">
    <entity>
      <identifier scheme="http://www.sec.gov/CIK">0001133416</identifier>
      <segment><xbrldi:explicitMember dimension="dei:LegalEntityAxis">galt:GalectinSciencesLlcMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:CounterpartyNameAxis">galt:SbhSciencesIncMember</xbrldi:explicitMember><xbrldi:explicitMember dimension="us-gaap:FiniteLivedIntangibleAssetsByMajorClassAxis">us-gaap:InProcessResearchAndDevelopmentMember</xbrldi:explicitMember></segment>
    </entity>
    <period>
      <instant>2014-01-31</instant>
    </period>
  </context>
  <unit id="iso4217_USD">
    <measure>iso4217:USD</measure>
  </unit>
  <unit id="pure">
    <measure>pure</measure>
  </unit>
  <unit id="iso4217_USD_per_shares">
    <divide>
      <unitNumerator>
        <measure>iso4217:USD</measure>
      </unitNumerator>
      <unitDenominator>
        <measure>shares</measure>
      </unitDenominator>
    </divide>
  </unit>
  <unit id="shares">
    <measure>shares</measure>
  </unit>
</xbrl>





