0001193125-21-101402 | 10-K | XBRL Viewer | Galectin Therapeutics INC

Cover - USD ($) $ in Millions	12 Months Ended
Cover - USD ($) $ in Millions	Dec. 31, 2020	Feb. 28, 2021	Jun. 30, 2020
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Registrant Name	GALECTIN THERAPEUTICS INC
Entity Central Index Key	0001133416
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Trading Symbol	GALT
Entity Public Float			$ 126
Entity Common Stock, Shares Outstanding		57,156,030
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Interactive Data Current	Yes
Entity Address, State or Province	GA
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	NV
Entity File Number	001-31791
Entity Tax Identification Number	04-3562325
Entity Address, Address Line One	4960 Peachtree Industrial Blvd.,
Entity Address, Address Line Two	Suite 240
Entity Address, City or Town	Norcross
Entity Address, Postal Zip Code	30071
City Area Code	678
Local Phone Number	620-3186
ICFR Auditor Attestation Flag	false

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 27,142	$ 47,480
Prepaid expenses and other current assets	2,323	729
Total current assets	29,465	48,209
Property and equipment, net
Other	135	258
Total assets	29,600	48,467
Current liabilities:
Accounts payable	1,292	1,661
Accrued expenses	4,042	1,093
Accrued dividends payable	65	66
Total current liabilities	5,399	2,820
Other liabilities	8	52
Total liabilities	5,407	2,872
Commitments and contingencies (Note 10)
Stockholders' equity:
Undesignated stock, $0.01 par value; 20,000,000 shares authorized at December 31, 2020 and 2019, 20,000,000 shares designated at December 31, 2020 and 2019, respectively
Common stock, $0.001 par value; 100,000,000 shares authorized at December 31, 2020 and 2019, 57,077,055 and 56,894,642 issued and outstanding at December 31, 2020 and 2019, respectively	56	56
Additional paid-in capital	261,883	259,673
Accumulated deficit	(239,996)	(216,394)
Total stockholders' equity	22,470	43,872
Total liabilities, redeemable convertible preferred stock and stockholders' equity	29,600	48,467
Series C 6% super dividend redeemable convertible preferred stock
Current liabilities:
Convertible preferred stock, value	1,723	1,723
Series A 12% convertible preferred stock
Stockholders' equity:
Convertible preferred stock, value	$ 527	$ 537

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Undesignated stock, par value	$ 0.01	$ 0.01
Undesignated stock, shares authorized	20,000,000	20,000,000
Undesignated stock, shares designated	20,000,000	20,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, issued	57,077,055	56,894,642
Common stock, outstanding	57,077,055	56,894,642
Series C 6% super dividend redeemable convertible preferred stock
Convertible preferred stock, shares authorized	1,000	1,000
Convertible preferred stock, shares issued	176	176
Convertible preferred stock, shares outstanding	176	176
Convertible preferred stock, redemption value	$ 8,546,000
Convertible preferred stock, liquidation value	$ 1,786,000
Series A 12% convertible preferred stock
Convertible preferred stock, shares authorized	1,742,500	1,742,500
Convertible preferred stock, issued	1,302,500	1,327,500
Convertible preferred stock, outstanding	1,302,500	1,327,500
Convertible preferred stock, liquidation value	$ 1,302,500

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 17,976	$ 7,467
General and administrative	5,468	5,971
Total operating expenses	23,444	13,438
Total operating loss	(23,444)	(13,438)
Other income (expense):
Interest income	66	231
Interest expense	(87)	(87)
Total other income (expense)	(21)	144
Net loss	(23,465)	(13,294)
Preferred stock dividends	(137)	(263)
Warrant modification (Note 5)	0	(6,622)
Net loss applicable to common stockholders	$ (23,602)	$ (20,179)
Basic and diluted net loss per share	$ (0.41)	$ (0.39)
Shares used in computing basic and diluted net loss per share	57,029	52,238

Condensed Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Series A 12% convertible preferred stock	Series B-1 12% convertible preferred stock	Series B-2 12% convertible preferred stock	Series B-3 8% convertible preferred stock	Series C super dividend redeemable convertible preferred stock dividend	Series A 12% convertible preferred stock	Series B-1 12% convertible preferred stock	Series B-2 12% convertible preferred stock	Series B-3 8% convertible preferred stock	Common Stock [Member]	Common Stock [Member] Series A 12% convertible preferred stock	Common Stock [Member] Series C super dividend redeemable convertible preferred stock dividend	Common Stock [Member] Series B Convertible Preferred Stock [Member]	Additional Paid-In Capital	Additional Paid-In Capital Series A 12% convertible preferred stock	Additional Paid-In Capital Series C super dividend redeemable convertible preferred stock dividend	Additional Paid-In Capital Series B Convertible Preferred Stock [Member]	Retained Deficit	Retained Deficit Series A 12% convertible preferred stock	Retained Deficit Series B-1 12% convertible preferred stock	Retained Deficit Series B-2 12% convertible preferred stock	Retained Deficit Series B-3 8% convertible preferred stock	Retained Deficit Series C super dividend redeemable convertible preferred stock dividend
Stockholders' Equity (Deficit), Balance (in shares) at Dec. 31, 2018							1,327,500	900,000	2,100,000	2,508,000	41,190,905
Stockholders' Equity (Deficit), Balance at Dec. 31, 2018	$ 5,175						$ 537	$ 1,761	$ 3,697	$ 1,224	$ 41				$ 194,130				$ (196,215)
Temporary Equity, Balance (in shares) at Dec. 31, 2018						176
Temporary Equity, Balance at Dec. 31, 2018						$ 1,723
Convertible preferred stock dividend		$ (80)	$ (6)	$ (15)	$ (9)	$ (51)										$ 49	$ 53			$ (129)	$ (6)	$ (15)	$ (9)	$ (104)
Convertible preferred stock dividend (in shares)												13,275	14,280
Issuance of common stock	47,819										$ 10				47,809
Issuance of common stock (in shares)											11,150,620
Issuance of common stock for warrant exercises	2,500										$ 1				2,499
Issuance of common stock for warrant exercises (in shares)											585,223
Issuance of common stock for stock option exercises	$ 150														150
Issuance of common stock for stock option exercises ( in shares)	150,993										150,993
Conversion of Series B Convertible Preferred to common								$ (1,767)	$ (3,697)	$ (1,224)				$ 4				$ 6,678
Conversion of Series B Convertible Preferred to common (in shares)								(900,000)	(2,100,000)	(2,508,000)				3,789,346
Conversion of Series A Convertible Preferred to common								(900,000)	(2,100,000)	(2,508,000)				3,789,346
Conversion of Series A Convertible Preferred to common (in shares)								$ (1,767)	$ (3,697)	$ (1,224)				$ 4				$ 6,678
Warrant modification (Note 5)															6,622				(6,622)
Temporary Equity, Balance (in shares) at Dec. 31, 2019						176
Net loss	$ (13,294)																		(13,294)
Temporary Equity, Balance at Dec. 31, 2019						$ 1,723
Stock-based compensation on expense	1,683														1,683
Stockholders' Equity (Deficit), Balance (in shares) at Dec. 31, 2019							1,327,500				56,894,642
Stockholders' Equity (Deficit), Balance at Dec. 31, 2019	43,872						$ 537				$ 56				259,673				(216,394)
Convertible preferred stock dividend																$ 61	$ 76			$ (61)				$ (76)
Convertible preferred stock dividend (in shares)												26.300	33,416
Issuance of common stock	44														44
Issuance of common stock (in shares)											14,452
Issuance of common stock for warrant exercises	$ 219														219
Issuance of common stock for warrant exercises (in shares)											84,624
Issuance of common stock for stock option exercises ( in shares)	106,847
Conversion of Series B Convertible Preferred to common	$ 1						$ (10)								11
Conversion of Series B Convertible Preferred to common (in shares)							(25,000)				4,553
Conversion of Series A Convertible Preferred to common							(25,000)				4,553
Conversion of Series A Convertible Preferred to common (in shares)	1						$ (10)								11
Temporary Equity, Balance (in shares) at Dec. 31, 2020						176
Net loss	(23,465)																		(23,465)
Temporary Equity, Balance at Dec. 31, 2020						$ 1,723
Stock-based compensation on expense	1,799										$ 19,068				1,799
Stockholders' Equity (Deficit), Balance (in shares) at Dec. 31, 2020							1,302,500	0	0	0	57,077,055
Stockholders' Equity (Deficit), Balance at Dec. 31, 2020	$ 22,470						$ 527	$ 0	$ 0	$ 0	$ 56				$ 261,883				$ (239,996)

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (23,465)	$ (13,294)
Adjustments to reconcile net loss to net cash from operating activities:
Amortization of right to use asset	36	35
Stock-based compensation expense	1,799	1,683
Non-cash interest expense	87	87
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,594)	(356)
Accounts payable and accrued expenses	2,536	997
Net cash from operating activities	(20,601)	(10,848)
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash from investing activities
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock and warrants	263	50,469
Payment of preferred stock dividends	0	(394)
Net cash from financing activities	263	50,075
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(20,338)	39,227
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	47,480	8,253
CASH AND CASH EQUIVALENTS, END OF PERIOD	27,142	47,480
NONCASH FINANCING ACTIVITIES:
Payment of preferred stock dividends in common stock	$ 137	$ 102

Nature of Business, Basis of Presentation and Liquidity

12 Months Ended

Dec. 31, 2020

Disclosure Text Block [Abstract]

Nature of Business, Basis of Presentation and Liquidity

1.	Nature of Business, Basis of Presentation and Liquidity

Galectin

Therapeutics Inc. and subsidiaries (the “Company”) is a clinical stage biopharmaceutical

company

that is applying its leadership in galectin science and drug development to create new therapies for fibrotic disease and cancer. These candidates are based on the Company’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.

The Company was founded in July 2000, was incorporated in the State of Nevada in January 2001 under the name

“Pro-Pharmaceuticals,

Inc.,” and changed its name to “Galectin Therapeutics Inc.” on May 26, 2011.

The Company has operated at a loss since its inception and has had no revenues. The Company anticipates that losses will continue for the foreseeable future. At December 31, 2020, the Company had $27,142,000 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 (see Note 8), to fund currently planned operations at least through March 31, 2022. We will require more cash to fund our operations after March 31, 2022 and believe we will be able to obtain additional financing. The currently planned operations include costs related to our adaptively designed NAVIGATE Phase 2b/3 clinical trial. Currently, we expect to require an additional approximately

$45-$50 million

to cover costs of the trial to reach the planned interim analysis estimated to occur in the second half of 2023 along with drug manufacturing and other scientific support activities and general and administrative costs. However, there can be no assurance that we will be successful in obtaining such new financing or, if available, that such financing will be on terms favorable to us. If we are unsuccessful in raising additional capital to fund operations before March 31, 2022, we may be required to cease operations.

The Company is subject to a number of risks similar to those of clinical stage companies, including dependence on key individuals, uncertainty of product development and generation of revenues, dependence on outside sources of capital, risks associated with clinical trials of products, dependence on third-party collaborators for research operations, need for regulatory approval of products, risks associated with protection of intellectual property, and competition with larger, better-capitalized companies. Successful completion of the Company’s development program and, ultimately, the attainment of profitable operations is dependent upon future events, including obtaining adequate financing to fulfill its development activities and achieving a level of revenues adequate to support the Company’s cost structure. There are no assurances that the Company will be able to obtain additional financing on favorable terms, or at all, or successfully market its products.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2020

Summary of Significant Accounting Policies

2.	Summary of Significant Accounting Policies

The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“GAAP”).

Basis of Consolidation.

The consolidated financial statements include the accounts of the Company and Galectin Therapeutics Security Corp., its wholly-owned subsidiary, which was incorporated in Delaware on December 23, 2003 and Galectin Sciences LLC (see Note 11). All intercompany transactions have been eliminated.

Use of Estimates.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and judgments that may affect the reported amounts of assets, liabilities, equity, revenue, expenses and related disclosure of contingent assets and liabilities. Management’s estimates and judgments include assumptions used in stock option valuations, useful lives of property and equipment and intangible assets, accrued liabilities, deferred income taxes and various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates under different assumptions or conditions.

Fair Value Measurements

. The Company has certain financial assets and liabilities recorded at fair value. Fair values determined by Level 1 inputs utilize observable data such as quoted prices in active markets. Fair values determined by Level 2 inputs utilize data points other than quoted prices in active markets that are observable either directly or indirectly. Fair values determined by Level 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 estimated value of accounts payable and accrued expenses approximates their carrying value due to their short-term nature. There were no Level 2 or 3 assets or liabilities at December 31, 2020 or 2019.

Cash and Cash Equivalents.

The Company considers all highly-liquid investments with original maturities of 90 days or less at the time of acquisition to be cash equivalents. The Company had no cash equivalents at December 31, 2020 or 2019.

Prepaid Expenses and Other Current Assets.

Prepaid expenses and other assets consist principally of prepaid insurance, deposits related to the NAVIGATE trial and deferred financing costs (see Note 8).

Property and Equipment.

Property and equipment, including leasehold improvements, are stated at cost, net of accumulated depreciation and amortization, and are depreciated or amortized using the straight-line method over the estimated useful lives of the related assets of generally three years for computers and office equipment, five years for furniture and fixtures and the shorter of the useful life or life of the lease for leasehold improvements.

Security Deposit.

At December 31, 2020 and 2019, the Company had a security deposit of $6,000 for leased office space included in Prepaid Expenses and Other Current Assets.

Long-Lived Assets.

The Company reviews all long-lived assets for impairment whenever events or circumstances indicate the carrying amount of such assets may not be recoverable. Recoverability of assets to be held or used is measured by comparison of the carrying value of the asset to the future undiscounted net cash flows expected to be generated by the asset. If such asset is considered to be impaired, the impairment recognized is measured by the amount by which the carrying value of the asset exceeds the discounted future cash flows expected to be generated by the asset. There were no impairments of long-lived assets at December 31, 2020 or 2019.

Accrued Expenses

. As part of the process of preparing our consolidated financial statements, we are required to estimate accrued expenses. This process involves identifying services that third parties have performed on our behalf and estimating the level of service performed and the associated cost incurred on these services as of each balance sheet date in our consolidated financial statements. Examples of estimated accrued expenses include professional service fees, such as those arising from the services of attorneys and accountants and accrued payroll expenses. In connection with these service fees, our estimates are most affected by our understanding of the status and timing of services provided relative to the actual services incurred by the service providers. In the event that we do not identify certain costs that have been incurred or we under- or over-estimate the level of services or costs of such services, our reported expenses for a reporting period could be understated or overstated. The date on which certain services commence, the level of services performed on or before a given date, and the cost of services are often subject to our judgment. We make these judgments based upon the facts and circumstances known to us in accordance with accounting principles generally accepted in the U.S.

Warrants.

The Company has issued common stock warrants in connection with the execution of certain equity and debt financings. The fair value of warrants is determined using the Black-Scholes option-pricing model using assumptions regarding volatility of our common share price, remaining life of the warrant, and risk-free interest rates at each period end. There were no warrant liabilities as of December 31, 2020 or 2019.

Research and Development Expenses.

Research and development expenses, including personnel costs, allocated facility costs, lab supplies, outside services, contract laboratory costs related to manufacturing drug product, clinical trials and preclinical studies are charged to research and development expense as incurred. The Company accounts for nonrefundable advance payments for goods and services that will be used in future research and development activities as expense when the service has been performed or when the goods have been received. Our current NAVIGATE clinical trial is being supported by third-party contract research organizations, or CROs, and other vendors. We accrue expenses for clinical trial activities performed by CROs based upon the estimated amount of work completed on each trial. For clinical trial expenses and related expenses associated with the conduct of clinical trials, the significant factors used in estimating accruals include the number of patients enrolled, the number of active clinical sites, and the duration for which the patients have been enrolled in the trial. We monitor patient enrollment levels and related activities to the extent possible through internal reviews, review of contractual terms and correspondence with CROs. We base our estimates on the best information available at the time. We monitor patient enrollment levels and related activities to the extent possible through discussions with CRO personnel and based our estimates of clinical trial costs on the best information available at the time. However, additional information may become available to us which will allow us to make a more accurate estimate in future periods. In that event, we may be required to record adjustments to research and development expenses in future periods when the actual level of activity becomes more certain.

Income Taxes.

The Company accounts for income taxes in accordance with the accounting rules that requires an asset and liability approach to accounting for income taxes based upon the future expected values of the related assets and liabilities. Deferred income tax assets and liabilities are determined based on the differences between the financial reporting and tax bases of assets and liabilities and for tax loss and credit carry forwards and are measured using the expected tax rates estimated to be in effect when such basis differences reverse. Valuation allowances are established, if necessary, to reduce the deferred tax asset to the amount that will, more likely than not, be realized.

Concentration of Credit Risk.

Financial instruments that subject the Company to credit risk consist of cash and cash equivalents and certificates of deposit. The Company maintains cash and cash equivalents and certificates of deposit with well-capitalized financial institutions. At times, those amounts may exceed federally insured limits. The Company has no significant concentrations of credit risk.

Stock-Based Compensation.

Stock-based compensation cost is measured at the grant date based on the fair value of the award and is recognized as expense over the service period, which generally represents the vesting period. For awards that have performance-based vesting conditions the Company recognizes the expense over the estimated period that the awards are expected to be earned. The Company generally uses the Black-Scholes option-pricing model to calculate the grant date fair value of stock options. The expense recognized over the service period is required to include an estimate of the awards that will be forfeited.

Recently Adopted Accounting Standards

. In December 2019, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”)

No. 2019-12,

“Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU

2019-12”),

which is intended to simplify various aspects related to accounting for income taxes. ASU

2019-12

removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This standard will be effective for the Company’s interim and annual periods beginning with the first quarter of fiscal 2021 and must be applied on a modified retrospective basis. This standard will not materially impact the Company’s consolidated financial statements.

Property and Equipment

12 Months Ended

Dec. 31, 2020

Property and Equipment

3.	Property and Equipment

Property and equipment consist of the following at December 31:


	2020			2019
	(in thousands)
Leasehold improvements	$	2		$	2
Computer and office equipment		13			13
Furniture and fixtures		59			59

Total		74			74
Less accumulated depreciation and amortization		(74	)		(74	)

Property and equipment — net	$	—		$	—

Depreciation and amortization expense for the years ended December 31, 2020 and 2019 was $0 and $0, respectively.

Accrued Expenses

12 Months Ended

Dec. 31, 2020

Accrued Expenses

4.	Accrued Expenses

Accrued expenses consist of the following at December 31:


	2020		2019
	(in thousands)
Legal and accounting fees	$	122	$	81
Accrued compensation		789		973
Lease liability		44		39
Accrued research and development costs and other		3,087		—

Total	$	4,042	$	1,093

Stockholders' Equity

12 Months Ended

Dec. 31, 2020

Stockholders' Equity

5.	Stockholders’ Equity

At December 31, 2020, the Company had 100,000,000 shares of common stock and 20,000,000 undesignated shares authorized. As of December 31, 2020, 1,742,500 shares have been designated for Series A 12% Convertible Preferred Stock, 900,000 shares have been designated for Series

B-1

Convertible Preferred Stock, 2,100,000 shares have been designated for Series

B-2

Convertible Preferred Stock, 1,000 shares have been designated for Series C Super Dividend Convertible Preferred Stock, 2,508,000 shares have been designated for Series

B-3

Convertible Preferred Stock, 12,748,500 have been designated as common stock and no shares remain undesignated. All issued and outstanding shares of Series

B-1,

Series

B-2

and Series

B-3

Preferred Stock were converted into Common Stock on January 19, 2019.

2020 At Market Issuance of Common Stock

On May 11, 2020, the Company entered into an At Market Issuance Sales Agreement (the “2020 At Market Agreement”) 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 $40.0 million from time to time through the sales agent. Sales of the Company’s common stock through the sales agent, if any, will be made by any method that is deemed an “at the market” 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 2020 At Market Agreement. In June 2020, the Company issued 14,452 shares of its common stock under the 2020 At Market Agreement for net proceeds of approximately $44,000.

2017 At Market Issuance of Common Stock

On May 19, 2017, the Company entered into an At Market Issuance Sales Agreement (the “2017 At Market Agreement”) 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 million from time to time through the sales agent. Sales of the Company’s common stock through the sales agent, if any, will be made by any method that is deemed an “at the market” 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 year ended December 31, 2019, the Company issued 662,459 shares of its common stock under the 2017 At Market Agreement for net proceeds of approximately $2,930,000. There were no issuances of common stock under the 2017 At Market Agreement in 2020, and the 2017 At Market Agreement was terminated in May 2020.

Rights Offering

On May 23, 2019, the Company completed an offering of common stock and warrants to its shareholders of record as of April 29, 2019. In the offering, the Company received approximately $44.9 million for the issuance of 10,488,161 shares of common stock and warrants which may be exercised for 2,622,154 shares of common stock. The warrants may be exercised at $7.00 per share of common stock and expire on May 23, 2026. The warrants were valued at approximately $8.2 million as of the issuance, using the closing price of $4.01, a life of 7 years, a volatility of 101% and a risk-free interest rate of 2.33%. Based upon the Company’s analysis of the criteria contained in ASC Topic

815-40,

“Derivatives and Hedging — Contracts in Entity’s Own Equity” the Company has determined that warrants issued in connection with this financing transaction were not derivative liabilities and therefore, were recorded as additional

paid-in

capital.

Series A 12% Convertible Preferred Stock — February 4, 2008 Private Placement

On February 4, 2008, the Company closed a private placement begun in October 2007 of its Series A 12% Convertible Preferred Stock (“Series A”) and related warrants. In this transaction, the Company sold units of securities at $6.00 per unit, each unit comprised of (i) one share of Series A Preferred, (ii) a warrant to purchase one share of common stock for $9.00, and (iii) a warrant to purchase one share of common stock for $12.00. Each share of the Series A is entitled to dividends at the rate of 12% per annum payable at the Company’s option in cash or shares of common stock valued at the higher of $6.00 per share or 100% of the value weighted average price of the Company’s share price for the 20 consecutive trading days prior to the applicable dividend payment date. Dividends are payable semi-annually on March 30 and September 30. The dividend paid on the initial dividend payment date is calculated from the date the Company deposited each subscription advance.

The shares of Series A are entitled to vote as a class with the Company’s common stock and each share of Series A is convertible at any time to

one-sixth

of a share of common stock, subject to adjustment in the event of a stock dividend, stock split or combination, reclassification or similar event. The Company has the right to require conversion if the closing price of the common stock exceeds $18.00 for 15 consecutive trading days and a registration statement covering the resale of the shares of common stock issuable upon conversion of the Series A is then in effect. Each warrant is exercisable solely for cash beginning August 3, 2008 and expired on February 4, 2012. The exercise price of each warrant is adjustable in the event of a stock split or stock combination, capital reorganization, merger or similar event.

In 2020, 25,000 shares of Series A were converted into 4,553 shares of common stock which included 387 shares relating to the prorated dividend prior to conversion. There were no shares of Series A converted into shares of common stock in 2019. Prior to 2018, a total of 410,000 shares of Series A had been converted into 69,312 shares of common stock.

Series B Convertible Preferred Stock

On February 12, 2009, the Company entered into a securities purchase agreement (the “10X Agreement”) pursuant to which it agreed to issue and sell to 10X Fund LP, at two or more closings, up to: (i) 3,000,000 shares its Series

B-1

and

B-2

convertible preferred stock with an aggregate stated value of $6.0 million and convertible into 2,000,000 shares of common stock at December 31, 2011 and (ii) warrants to purchase 6,000,000 shares of common stock.

Through a series of closings from February 2009 through May 2010, the Company issued and sold, pursuant to the 10X Agreement, a total of (i) 900,000 shares of Series

B-1

convertible preferred stock (“Series

B-1

convertible preferred stock” or “Series

B-1”)

and related common stock warrants for 1,800,000 shares of common stock and (ii) 2,100,000

shares of Series

B-2

convertible preferred stock (“Series

B-2

convertible preferred stock” or “Series

B-2”)

and related warrants for 4,200,000 shares of common stock for total net proceeds of $5,483,000.

On September 22, 2016, the Company entered into a securities purchase agreement (the

“B-3

Agreement”) pursuant to which it agreed to issue and sell to 10X Fund LP: (i) 1,500,000 shares its Series

B-3

convertible preferred stock (“Series

B-3

preferred stock” or

“Series B-3”)

with an aggregate stated value and proceeds of $1.5 million and convertible into 892,349 shares of

common stock, and (ii) warrants to purchase up to 669,262 shares of common stock. Also, pursuant to agreements signed on September 22, 2016 with 10X Fund LP, the Company issued 875,000 warrants to purchase common stock in exchange in exchange for the 10X Fund LP agreeing not to sell any shares of common or preferred stock in the Company for 18 months, except in limited circumstances. Additionally, as previously agreed to by the 10X Fund LP, the sole holder of the Company’s Series

B-1,

Series

B-2

and Series

B-3

preferred stock (collectively, with the Series

B-1

and Series

B-2,

the “Series B”), in the Second Amended and Restated Certificate of Designation of Preferences, Rights and Limitations of Series B preferred stock we removed the ability of the holders of the Series B to cause a redemption of their shares of Series B. Accordingly, the Company accounted for the removal of this redemption feature as a modification and reclassified the Series

B-1

and Series

B-2

preferred stock into permanent equity at September 30, 2016 and forward.

On December 23, 2016, the Company and 10X Fund LP amended the

B-3

Agreement whereby the Company agreed to issue and sell to 10X Fund LP an additional (i) 1,008,000 shares of its

B-3

preferred

stock with an aggregate stated value and proceeds of $1.0 million and convertible into 896,997 shares of common stock, and (ii) warrants to purchase up to 924,780 shares of common stock.

On January 11, 2019, 10X Fund L.P., converted all of its Series B Convertible Preferred Stock into Common Stock of Galectin Therapeutics. Pursuant to the terms of the conversion, as of January 11, 2019, 10X Fund L.P. converted 5,508,000 shares of its Series

B-1,

B-2

and

B-3

Convertible Preferred Stock into 3,789,346 shares of Common Stock of Galectin Therapeutics. All special voting rights and protective provisions that previously benefited the Series B Preferred Stock were extinguished by the conversion to Common Stock.

In connection with the conversion of the Series B Preferred Stock, the Company extended by five years the exercise date of warrants for 3,579,642 shares of Common Stock issued by the Company in connection with sale of the Series

B-1

and Series

B-2

Preferred Stock. Before the extension, the warrants had various expiration dates in 2019 and 2020. The warrant amendments give 10X Fund the right to nominate one director to the Company’s board of directors. Previously, under the now extinguished voting rights of the Series B Preferred, 10X Fund had the right to name two directors and nominate an additional three directors.

The Company has accounted for the modified terms of the warrants pursuant to ASC 718, Stock Compensation, whereby the Company has recognized a charge for the change in fair value of the warrants immediately before and immediately after the modification. In January 2019, the Company recognized a

one-time

non-cash

charge of $6,622,000 related to the extension of the 3,579,642 warrants. The following assumptions were used to value the extension of the warrants immediately before and immediately after the modification: a) immediately before the modification — an expected life range of 0.09 to 1.33 years, volatility of 98%, risk free interest rate range of 2.4% to 2.59% and zero dividends and; b) immediately following the modification — an expected life range of 5.09 to 6.33 years, volatility range of 106%, risk free interest rate range of 2.56% to 2.6% and zero dividends.

Series C 6% Super Dividend Redeemable Convertible Preferred Stock

On December 29, 2010, the Company designated and authorized the sale and issuance of up to 1,000 shares of Series C Super Dividend Redeemable Convertible Preferred Stock (“Series C”) with a par value of $0.01 and a stated value equal to $10,000 (the “Stated Value”).

On December 30, 2010, the Company sold and issued 212 shares of Series C at a price of $10,000 per share for gross proceeds of $2,120,000. The Company incurred $47,000 of cash transaction costs resulting in net cash proceeds of $2,073,000. In addition, the Company issued 500 warrants exercisable at $7.20 to a placement agent which had a de minimis value. Additionally, in January 2011, the Company sold and issued 13 shares of Series C at a price of $10,000 per share for gross proceeds of $130,000.

The terms of the Series C are as follows:

Conversion Rights

. Each holder of Series C may convert all, but not less than all, of his Series C shares plus accrued and unpaid dividends into Common Stock at the price of $6.00 per share of Common Stock (“Conversion Price”), such that approximately 1,667 shares of Common Stock will be issued per each converted share of Series C (accrued and unpaid dividends will be issued as additional shares). At December 31, 2018 and 2017, the 176 outstanding shares of Series C were convertible into a total of approximately 293,340 shares of Common Stock.

Subject to the continuing obligation to pay post conversion dividends, the Company may convert all, but not less than all, of the Series C (plus all accrued and unpaid dividends) into Common Stock, at the Conversion Price, upon such time that the closing price of the Common Stock is no less than $18.00 per share for 15 consecutive trading days.

Dividends

. Holders of Series C shall be entitled to receive cumulative

non-compounding

dividends at the rate per share of Series C equal to the greater of (i) 6% per annum of the Stated Value (also defined as the “Floor”) or (ii) 2.5% of net sales until the total dividends paid is equal to the initial investment and 1.25% of net sales thereafter. The maximum amount each Series C shareholder will receive in dividend payments is equal to $100,000 (the “Maximum Payout”). For purposes of this dividend calculation, net sales shall mean gross revenues actually received by the Company, from the sale or licensing of the product DAVANAT

(GM-CT-01),

less chargebacks, returns, expenses attributable to product recalls, duties, customs, sales tax, freight, insurance, shipping expenses, allowances and other customary deductions.

The dividend shall be payable in arrears semiannually on March 31 and September 30, beginning with the first such date after the original issue date; provided, however, that all dividends and all other distributions shall cease, and no further dividends or other distributions shall be paid, in respect of each share of Series C from and after such time that the Maximum Payout has been paid in respect of such share of Series C. Such dividends shall be payable at the Company’s option either in cash or in duly authorized, fully paid and

non-assessable

shares of Common Stock valued at the higher of (i) $3.00 per share or (ii) the average of the Common Stock trading price for the ten (10) consecutive trading days ending on the trading day that is immediately prior to the dividend payment date.

Series C Post Conversion Dividend Right

. In the event that any share of Series C is converted into Common Stock before the Maximum Payout is paid in respect of such converted share of Series C, then the holder shall have the right to continue to receive dividends in respect of such converted share of Series C equal to the remaining payout (the “Series C Preferred Stock Post Conversion Dividend Right”) which shall be equal to the Maximum Payout less the cumulative dividends received through the conversion date. One share of Series C Preferred Stock Post Conversion Dividend Right shall be issued for each such converted share of Series C. The holder of each Series C Preferred Stock Post Conversion Dividend Right shall receive the remaining payout on an equal basis and in conjunction with the then outstanding shares of Series C and all the other then outstanding Series C Post Conversion Dividend Rights, in the same manner and subject to the same terms and conditions as applicable to the payment of dividends on each share of Series C, except that for purposes of calculating the dividend the Floor shall not apply. The Series C Preferred Stock Post Conversion Dividend Right shall have no stated value, liquidation preference or right to any dividends or distributions other than the remaining payout. The Series C Preferred Stock Post Conversion Right is subject to redemption in the same manner as outstanding Series C shares.

At the date of issuance, the Series C have an embedded dividend right to continue to receive dividend payments after conversion to common stock (the Series C Post Conversion Dividend Right) which requires bifurcation. The value of this post conversion dividend right on the date of issuance was determined to be de minimis due to the fact that the payment of a dividend stream other than the 6% dividend and conversion of Series C prior to the Company achieving sales of

GM-CT-01

was deemed improbable at that time. Upon a conversion of the Series C, the Company will be required to record a liability and the related expense during the period of conversion.

In July 2011, 5 shares of Series C were converted into 8,334 shares of common stock and 5 Series C Post Conversion Dividend Rights (Dividend Rights) were issued. In 2013, 24 shares of Series C were converted into 40,193 shares of common stock and 24 Dividend Rights were issued. In 2014, 20 shares of Series C were converted into 33,756 shares of common stock and 20 Dividend Rights were issued. Per the terms of the Series C, these Dividend Rights shall continue to participate in dividends, however the Floor shall not apply. At December 31, 2016 and 2015, these Dividend Rights were determined to have a de minimis value, as the payment of a dividend is considered improbable at this time. The Company will continue to evaluate and assess the Series C Post Conversion Dividend Right for each reporting period.

Liquidation Rights

. In the event of any liquidation, dissolution or winding up of the Company, either voluntarily or involuntarily, the holders of Series C will receive $10,000 per share plus accrued and unpaid dividends, payable prior and in preference to any distributions to the holders of Common Stock but after and subordinate to the Series A 12% Convertible Preferred Stock (“Series A”), Series

B-1

and Series

B-2,

subject to the Maximum Payout.

Redemption

. Upon a sale of the Company, the Company shall redeem all of the then outstanding shares of Series C and Series C Preferred Stock Post Conversion Rights within thirty (30) days after the transaction constituting the sale of the Company is closed and such closing is fully funded. The price to redeem a share of Series C and each redeemed Series C Preferred Stock Post Conversion Redemption Right shall be equal to (i) (A) the applicable return on investment (“ROI”) percentage, multiplied by (B) $10,000, minus (ii) the cumulative dividends received through the redemption date. The redemption price shall be payable at the Company’s option either in cash or in shares of common stock valued at the higher of (i) $3.00 per share or (ii) the average market price for the ten consecutive trading days ending immediately prior to the date of redemption. The ROI Percentage shall mean the percentage that applies as of the redemption date, as follows:

ROI Percentage


200%		before the second anniversary of the date of issuance;
250%		on or after the second anniversary of the date of issuance, but before the third anniversary of the date of issuance;


300%		on or after the third anniversary of the date of issuance, but before the fourth anniversary of the date of issuance;
350%		on or after the fourth anniversary of the date of issuance, but before the fifth anniversary of the date of issuance;
400%		on or after the fifth anniversary of the date of issuance, but before the sixth anniversary of the date of issuance;
450%		on or after the sixth anniversary of the date of issuance, but before the seventh anniversary of the date of issuance;
500%		on or after the seventh anniversary of the date of issuance, but before the eighth anniversary of the date of issuance; and
550%		on or after the eighth anniversary of the date of issuance, but before the ninth anniversary of the date of issuance.

Due to the redemption feature, the Company has presented the Series C outside of permanent equity, in the mezzanine of the consolidated balance sheets at December 31, 2020 and 2019. At December 31, 2020, the Series C redemption value was $8,546,000.

Voting Rights

. The Series C shares have no voting rights.

Warrants

12 Months Ended

Dec. 31, 2020

Warrants

6. Warrants

Warrant activity is summarized as follows:


Outstanding at December 31, 2018	10,647,026
Issued	2,622,154
Exercised	(730,976	)
Canceled	—

Outstanding at December 31, 2019	12,538,204

Issued	—
Exercised	—
Canceled	—

Outstanding at December 31, 2020	12,538,204

The following table summarizes information with regard to outstanding warrants issued in connection with equity and debt financings and consultants as of December 31, 2020.


Issued in Connection With	Number Issued		Exercise Price		Exercisable Date		Expiration Date
February 12, 2009 Series B-1 Transaction $3.00 Investor Warrants — Class B		1,200,000	$	3.00		February 12, 2009		February 12, 2024
May 13, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		600,000	$	3.00		May 13, 2009		May 13, 2024
June 30, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		333,333	$	3.00		June 30, 2009		June 30, 2024
August 12, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		200,000	$	3.00		August 12, 2009		August 12, 2024
September 30, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		216,666	$	3.00		September 30, 2009		September 30, 2024


Issued in Connection With	Number Issued		Exercise Price		Exercisable Date		Expiration Date
November 4, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		106,666	$	3.00		November 4, 2009		November 4, 2024
December 8, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		133,143	$	3.00		December 8, 2009		December 8, 2024
January 29, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B		216,667	$	3.00		January 29, 2010		January 29, 2025
March 8, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B		223,334	$	3.00		March 8, 2010		March 8, 2025
April 30, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B		204,192	$	3.00		April 30, 2010		April 30, 2025
May 10, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B		143,166	$	3.00		May 10, 2010		May 10, 2025
November 25, 2015 Offering Warrants		1,180,240	$	2.50		May 25, 2016		May 25, 2021
September 22, 2016 Series B-3 Transaction $3.00 Investor Warrants		698,158	$	3.00		September 22, 2016		September 22, 2023
September 29, 2016 Series B-3 Transaction $3.00 Investor Warrants		846,100	$	3.00		September 29, 2016		September 29, 2023
December 22, 2016 Private placement warrants		1,466,204	$	5.00		December 22, 2016		December 23, 2023
December 23, 2016 Series B-3 Transaction $3.00 Investor Warrants		924,780	$	3.00		December 23, 2016		December 23, 2023
December 28, 2016 Private placement warrants		644,468	$	5.00		December 28, 2016		December 28, 2023
February 27, 2017 Private placement warrants		76,776	$	5.00		February 27, 2017		February 27, 2024
2018 and 2017 Warrants issued for services		2,157	$	5.00		Various dates in 2018 and 2017		Various dates in 2025 and 2024
December 19, 2017 Line of credit warrants		500,000	$	5.00		December 19, 2017		December 19, 2024
May 23, 2019 Rights offering warrants		2,622,154	$	7.00		May 23, 2019		May 23, 2026

Total outstanding warrants		12,538,204

Stock-Based Compensation

12 Months Ended

Dec. 31, 2020

Stock-Based Compensation

7.	Stock-Based Compensation

Summary of Stock-Based Compensation Plans

At December 31, 2020, the Company has a stock-based compensation plan where the Company’s common stock has been made available for equity-based incentive grants as part of the Company’s compensation programs. In December 2019, the Company adopted the 2019 Omnibus Equity Incentive Plan (the “2019 Plan”) which provided for the issuance of up to 4,000,000 shares of the Company’s common stock in the form of options, stock appreciation rights, restricted stock and other stock-based awards to employees, officers, directors, consultants and other eligible persons. At December 31, 2020, 2,822,000 shares were available for future grant under the 2019 Plan. Also, the Company previously had the 2009 Incentive Compensation Plan (the “2009 Plan”) which, after amendments, provided for issuance of up to 6,733,334 shares of the Company’s common stock in the form of options, stock appreciation rights, restricted stock and other stock-based awards to employees, officers, directors, consultants and other eligible persons. Provisions of the 2009 Plan stipulated that no grants could be made after February 2019; however, grants made prior to that date remain outstanding for their legal term.

In addition, the Company has awarded 1,477,379

non-plan

stock option grants to employees and

non-employees.

These

non-plan

grants have vesting periods and expiration dates similar to those options granted under the Incentive Plans. At December 31, 2020, 500,000

non-plan

grants were outstanding.

Stock-Based Compensation

Following is the stock-based compensation expense related to common stock options, restricted common stock, common stock warrants and deferred stock units:


	Year Ended December 31,
	2020		2019
Research and development	$	516	$	318
General and administrative		1,283		1,365

Total stock-based compensation expense	$	1,799	$	1,683

The fair value of the options granted is determined using the Black-Scholes option-pricing model. The following weighted average assumptions were used:


	2020			2019
Risk-free interest rate		1.26	%		2.68	%
Expected life of the options		6.0 years			6.0 years
Expected volatility of the underlying stock		97.9	%		103.7	%
Expected dividend rate		0	%		0	%

As noted above, the fair value of stock options is determined by using the Black-Scholes option pricing model. For all options granted since January 1, 2006 the Company has generally used option terms of between 5 to 10 years, generally with 5 to 6 years representing the estimated life of options granted to employees. The volatility of the common stock is estimated using historical volatility over a period equal to the expected life at the date of grant. The risk-free interest rate used in the Black-Scholes option pricing model is determined by reference to historical U.S. Treasury constant maturity rates with terms equal to the expected terms of the awards. An expected dividend yield of zero is used in the option valuation model, because the Company does not expect to pay any cash dividends on common stock in the foreseeable future. At December 31, 2020, the Company does not anticipate any option awards will be forfeited in the calculation of compensation expense due to the limited number of employees that receive stock option grants and the Company’s historical employee turnover.

The following table summarizes the stock option activity in the stock-based compensation plans:


	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2018		2,713,979		$	4.67
Granted		530,000			4.72
Forfeited/Cancelled		(92,730	)		2.91
Exercised		(150,993	)		1.83

Outstanding, December 31, 2019		3,000,256		$	4.88
Granted		1,095,000			2.51
Forfeited/Cancelled		(834	)		1.80
Exercised		(106,847	)		2.61

Outstanding, December 31, 2020		3,987,575		$	4.29		6.34	$	450

Exercisable, December 31, 2020		3,335,908		$	4.68		5.75	$	303

The aggregate intrinsic value in the table above represents the total

pre-tax

amount, net of exercise price, which would have been received by option holders if all option holders had exercised all options with an exercise price lower than the market price on December 31, 2020, based on the closing price of the Company’s common stock of $2.24 on that date.

The weighted-average grant-date fair values of options granted during 2020 and 2019 were $1.92 and $3.83, respectively. As of December 31, 2020 and 2019, there were unvested options to purchase 651,667 and 407,500 shares of common stock, respectively. Total expected unrecognized compensation cost related to such unvested options is $1,052,000 at December 31, 2020, which is expected to be recognized over a weighted-average period of 2.53 years.

The aggregate intrinsic value of stock options exercised for the year ended December 31, 2020 and 2019 was $39,792 and $594,302, respectively.

During the years ended December 31, 2020 and 2019, 850,833 and 130,490 options became vested, respectively. The total grant date fair value of options vested during the years ended December 31, 2020 and 2019 was $2,531,758 and $491,000, respectively.

The following table summarizes additional information regarding outstanding and exercisable options under our stock-based compensation plans at December 31, 2020:


	Options Outstanding						Options Exercisable
Exercise Price (Range)	Number of Shares		Weighted Average Remaining Contractual Life		Weighted Average Exercise Price		Number of Shares		Weighted Average Exercise Price
			(in years)
$0.87 – 1.00		190,500		5.95	$	0.88		190,500	$	0.88
$1.01 – 3.00		1,683,060		7.81		2.47		1,031,393		2.60
$3.01 – 5.00		1,053,040		7.17		4.35		1,053,040		4.35
$5.01 – 8.00		878,475		3.27		6.55		878,475		6.55
$8.01 – 13.38		182,500		3.06		13.38		182,500		13.38

		3,987,575		6.34	$	4.29		3,335,908	$	4.68

Restricted Stock Issuances

In January 2020, two directors elected to take restricted stock grants in lieu of cash retainers for 2020. A total of 32,693 shares of restricted stock valued at approximately $94,000 is being amortized to expense on a straight-line basis until January 9, 2021 when the stock vested in full.

In January 2019, two directors elected to take restricted stock grants in lieu of cash retainers for 2019. A total of 19,068 shares of restricted stock valued at approximately $90,000 is being amortized to expense on a straight-line basis until January 16, 2020 when the stock vested in full.

Deferred Stock Units

In September 2020, the Company entered into an employment agreement with its new Chief Executive Officer whereby 20% of his base salary and performance bonuses will be paid in cash, and 80% will be paid in the form of deferred stock units (“

DSUs

”) in accordance with the terms and subject to the provisions set forth in the DSU Agreement. DSUs credited to Mr. Lewis as of any date shall be fully vested and nonforfeitable at all times. The Company shall issue the shares underlying the outstanding whole number of DSUs credited to Mr. Lewis as follows: twenty five percent shall be issued on March 1, 2023, twenty five percent shall be issued on September 1, 2023 and fifty percent shall be issued on March 1, 2024. For the year ended December 31, 2020, approximately $132,000 of his compensation was recorded as stock compensation expense representing 50,307 shares of common stock to be issued under the DSU agreement with a weighted average grant date fair value of $2.62 per share. There is no unrecognized compensation expense related to the DSUs.

Line of Credit

12 Months Ended

Dec. 31, 2020

Line of Credit

8.	Line of Credit

The Company has a $10 million Line of Credit arrangement with Richard E. Uihlein, a director and shareholder pursuant to an agreement established in December, 2017 and amended in December, 2018 and January, 2019. Under the arrangement the Company may borrow up to $10 million from Mr. Uihlein on an unsecured basis and with any borrowings bearing interest at the Applicable Federal Rate for short terms loans published by the Internal Revenue Service (0.14% in January 2021). Borrowings may be made through December 31, 2021 with repayment due on December 31, 2022. In connection with the Line of Credit agreement, the Company issued to Mr. Uihlein warrants to purchase 1 million shares of the Company’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. As of the date of this Annual Report, there have been no borrowings under the Line of Credit.

The fair value of the 500,000 warrants vested at closing in December 2017 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

(non-current)

as a deferred financing cost and were to be amortized on a straight-line basis from December 19, 2017 through December 31, 2019. The remaining unamortized balance of the deferred financing cost on January 11, 2019 was adjusted to be recorded as expense on a straight-line basis through December 31, 2022. Amortization for the year ended December 31, 2020 and 2019 of $87,000 and $87,000, respectively, 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 31, 2022 reflecting the second extension.

Loss Per Share

12 Months Ended

Dec. 31, 2020

Loss Per Share

9.	Loss Per Share

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

in-the-

money 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.


	Year Ended December 31,
	(in thousands, except per share amounts)
	2020		2019
Net loss		$ (23,465)		$ (13,294)
Preferred stock dividends		(137)		(263)
Warrant modification		—		(6,622)

Net loss applicable to common stockholders		$ (23,602)		$ (20,179)

Basic and diluted net loss per share		$ (0.41)		$ (0.39)
Shares used in computing basic and diluted net loss per share		57,029		52,238

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:


	Year Ended December 31,
	2020 (Shares)		2019 (Shares)
Warrants to purchase shares of common stock		12,538,204		12,538,204
Options to purchase shares of common stock		3,987,575		3,000,256
Shares of common stock issuable upon conversion preferred stock		510,424		514,590

		17,036,203		16,053,050

Commitments and Contingencies

12 Months Ended

Dec. 31, 2020

Commitments and Contingencies

10.	Commitments and Contingencies

Lease Commitments

The Company has one operating lease for its office space which was amended effective January 1, 2019 for a term of 38 months with no residual value guarantees or material restrictive covenants. The amended lease provided for free rent for the first two months of the lease and continues the security deposit of $6,000. In addition to base rental payments included in the contractual obligations table below, the Company is responsible for our

pro-rata

share of the operating expenses for the building. Our lease cost for the years ended December 31, 2020 and 2019 was $44,000 and $44,000 and is included in general and administrative expenses. As of December 31, 2020, the right to use lease asset consisted of $48,000 and is included in other assets. Also, at December 31, 2020, current lease liability of $44,000 is included in accrued expenses and other and noncurrent lease liability of $8,000 is in other noncurrent liabilities.

Maturity of operating lease as of December 31, 2020 in thousands:


2021	$	48
2022		8

Total		56

Less imputed interest		4

Present value of lease liability	$	52

The discount rate used in calculating the present value of the lease payments was 11.04%.

Legal Proceedings

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 pending legal proceedings.

Clinical Trial and Research Contingencies

The Company has entered into agreements with contractors for research and development activities to further its product candidates. The contracts generally may be canceled at any time by providing thirty days’ notice.

Galectin Sciences LLC

12 Months Ended

Dec. 31, 2020

Galectin Sciences LLC

11.	Galectin Sciences LLC

In January 2014, we created Galectin Sciences, LLC (the “LLC” or “Investee”), a collaborative joint venture

co-owned

by SBH Sciences, Inc. (“SBH”), to research and develop small organic molecule inhibitors of

galectin-3

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

in-process

research and development (“IPR&D”) contributed by SBH. The estimated fair value of the IPR&D contributed by SBH, on the date of contribution, was $400,000. Initially, the Company and SBH have a 50% equity ownership interest in the LLC, with neither party having control over the LLC. Accordingly, from inception through the fourth quarter of 2014, the Company accounted for its investment in the LLC using the equity method of accounting. Under the equity method of accounting, the Company’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’s share of the Investee’s earnings, losses and/or changes in capital. The estimated fair value of the IPR&D contributed to the LLC was immediately expensed upon contribution as there was no alternative future use available at the point of contribution. 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. As a result, the Company contributed the $73,000 needed for the fourth quarter of 2014 expenses of the LLC and an additional $1,711,000 in total from 2015 through 2018. The Company contributed $448,000 and $147,000 for the LLC expenses (recorded in research and development expenses) in 2020 and 2019, and SBH contributed $35,000 in 2019 and a total of $123,000 in 2017 and 2016, respectively. As of December 31, 2020, the Company’s ownership percentage in the LLC was 83.4%. The Company accounts for the interest in the LLC as a consolidated, less than wholly owned subsidiary. Because the LLC’s equity is immaterial, the value of the

non-controlling

interest is also deemed to be immaterial. The Company’s portion of the LLC’s net loss for 2014, prior to the change in accounting discussed previously, was $400,000, which includes the Company’s proportionate share of the

non-cash

charge associated with the contributed IPR&D of $200,000.

Income Taxes

12 Months Ended

Dec. 31, 2020

Income Taxes

12.	Income Taxes

On December 22, 2017, the Tax Cuts and Jobs Act (2017 Tax Act) was enacted. The 2017 Tax Act includes a number of changes to existing U.S. tax laws that impact the Company, most notably a reduction of the U.S. corporate tax rate from 34% to 21%, for tax years beginning after December 31, 2017. The 2017 Tax Act also provides for the implementation of a territorial tax system, a

one-time

transition tax on certain foreign earnings, the acceleration of depreciation for certain assets placed into service after September 27, 2017 and other prospective changes beginning in 2018, including repeal of the domestic manufacturing deduction, acceleration of tax revenue recognition, capitalization of research and development expenditures, additional limitations on executive compensation and limitations on the deductibility of interest.

The components of the net deferred tax assets are as follows at December 31:


	2020			2019
	(in thousands)
Operating loss carryforwards	$	46,203		$	39,982
Tax credit carryforwards		910			910
Other temporary differences		5,438			5,278

	52,551			46,170
Less valuation allowance		(52,551	)		(46,170	)

Net deferred tax asset	$	—		$	—

The primary factors affecting the Company’s income tax rates were as follows:


	2020			2019
Tax benefit at U.S. statutory rates		(21	%)		(21	%)
State tax benefit		(4.7	%)		(4.7	%)
Permanent differences		0.8	%		0.8	%
Impact of the 2017 Tax Act		—			—
Other		(2.2	%)		(4.2	%)
Expiring state NOL’s		—			—
Changes in valuation allowance		27.1	%		29.1	%

	0		%	0		%

As of December 31, 2020, the Company has federal and state net operating loss carryforwards totaling $44,838,000 which will never expire as a result of the 2017 Tax Act. As of December 31, 2020, the Company has federal and state net operating loss carryforwards totaling $136,202,000 and $138,676,000 respectively, which expire through 2037. The net operating losses include Federal and State excess benefits related to stock options of $2,120,000 that will be charged to additional

paid-in

capital when utilized. In addition, the Company has federal and state research and development credits of $733,000 and $176,000, respectively, which expire through 2034. Ownership changes, as defined by Section 382 of the Internal Revenue Code, may have limited the amount of net operating loss carryforwards that can be utilized annually to offset future taxable income. Past and subsequent ownership changes could further affect the limitation in future years. Because of the Company’s limited operating history and its recorded losses, management has provided, in each of the last two years, a 100% valuation allowance against the Company’s net deferred tax assets.

The Company is subject to taxation in the U.S. and various states. Based on the history of net operating losses all jurisdictions and tax years are open for examination until the operating losses are utilized or the statute of limitations expires. As of December 31, 2020 and 2019, the Company does not have any significant uncertain tax positions.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2020
Basis of Consolidation	Basis of Consolidation. The consolidated financial statements include the accounts of the Company and Galectin Therapeutics Security Corp., its wholly-owned subsidiary, which was incorporated in Delaware on December 23, 2003 and Galectin Sciences LLC (see Note 11). All intercompany transactions have been eliminated.
Use of Estimates	Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and judgments that may affect the reported amounts of assets, liabilities, equity, revenue, expenses and related disclosure of contingent assets and liabilities. Management’s estimates and judgments include assumptions used in stock option valuations, useful lives of property and equipment and intangible assets, accrued liabilities, deferred income taxes and various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates under different assumptions or conditions.
Fair Value Measurements	Fair Value Measurements . The Company has certain financial assets and liabilities recorded at fair value. Fair values determined by Level 1 inputs utilize observable data such as quoted prices in active markets. Fair values determined by Level 2 inputs utilize data points other than quoted prices in active markets that are observable either directly or indirectly. Fair values determined by Level 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 estimated value of accounts payable and accrued expenses approximates their carrying value due to their short-term nature. There were no Level 2 or 3 assets or liabilities at December 31, 2020 or 2019.
Cash and Cash Equivalents	Cash and Cash Equivalents. The Company considers all highly-liquid investments with original maturities of 90 days or less at the time of acquisition to be cash equivalents. The Company had no cash equivalents at December 31, 2020 or 2019.
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets. Prepaid expenses and other assets consist principally of prepaid insurance, deposits related to the NAVIGATE trial and deferred financing costs (see Note 8).
Property and Equipment	Property and Equipment. Property and equipment, including leasehold improvements, are stated at cost, net of accumulated depreciation and amortization, and are depreciated or amortized using the straight-line method over the estimated useful lives of the related assets of generally three years for computers and office equipment, five years for furniture and fixtures and the shorter of the useful life or life of the lease for leasehold improvements.
Security Deposit	Security Deposit. At December 31, 2020 and 2019, the Company had a security deposit of $6,000 for leased office space included in Prepaid Expenses and Other Current Assets.
Long-Lived Assets	Long-Lived Assets. The Company reviews all long-lived assets for impairment whenever events or circumstances indicate the carrying amount of such assets may not be recoverable. Recoverability of assets to be held or used is measured by comparison of the carrying value of the asset to the future undiscounted net cash flows expected to be generated by the asset. If such asset is considered to be impaired, the impairment recognized is measured by the amount by which the carrying value of the asset exceeds the discounted future cash flows expected to be generated by the asset. There were no impairments of long-lived assets at December 31, 2020 or 2019.
Accrued Expenses	Accrued Expenses . As part of the process of preparing our consolidated financial statements, we are required to estimate accrued expenses. This process involves identifying services that third parties have performed on our behalf and estimating the level of service performed and the associated cost incurred on these services as of each balance sheet date in our consolidated financial statements. Examples of estimated accrued expenses include professional service fees, such as those arising from the services of attorneys and accountants and accrued payroll expenses. In connection with these service fees, our estimates are most affected by our understanding of the status and timing of services provided relative to the actual services incurred by the service providers. In the event that we do not identify certain costs that have been incurred or we under- or over-estimate the level of services or costs of such services, our reported expenses for a reporting period could be understated or overstated. The date on which certain services commence, the level of services performed on or before a given date, and the cost of services are often subject to our judgment. We make these judgments based upon the facts and circumstances known to us in accordance with accounting principles generally accepted in the U.S.
Warrants	Warrants. The Company has issued common stock warrants in connection with the execution of certain equity and debt financings. The fair value of warrants is determined using the Black-Scholes option-pricing model using assumptions regarding volatility of our common share price, remaining life of the warrant, and risk-free interest rates at each period end. There were no warrant liabilities as of December 31, 2020 or 2019.
Research and Development Expenses	Research and Development Expenses. Research and development expenses, including personnel costs, allocated facility costs, lab supplies, outside services, contract laboratory costs related to manufacturing drug product, clinical trials and preclinical studies are charged to research and development expense as incurred. The Company accounts for nonrefundable advance payments for goods and services that will be used in future research and development activities as expense when the service has been performed or when the goods have been received. Our current NAVIGATE clinical trial is being supported by third-party contract research organizations, or CROs, and other vendors. We accrue expenses for clinical trial activities performed by CROs based upon the estimated amount of work completed on each trial. For clinical trial expenses and related expenses associated with the conduct of clinical trials, the significant factors used in estimating accruals include the number of patients enrolled, the number of active clinical sites, and the duration for which the patients have been enrolled in the trial. We monitor patient enrollment levels and related activities to the extent possible through internal reviews, review of contractual terms and correspondence with CROs. We base our estimates on the best information available at the time. We monitor patient enrollment levels and related activities to the extent possible through discussions with CRO personnel and based our estimates of clinical trial costs on the best information available at the time. However, additional information may become available to us which will allow us to make a more accurate estimate in future periods. In that event, we may be required to record adjustments to research and development expenses in future periods when the actual level of activity becomes more certain.
Income Taxes	Income Taxes. The Company accounts for income taxes in accordance with the accounting rules that requires an asset and liability approach to accounting for income taxes based upon the future expected values of the related assets and liabilities. Deferred income tax assets and liabilities are determined based on the differences between the financial reporting and tax bases of assets and liabilities and for tax loss and credit carry forwards and are measured using the expected tax rates estimated to be in effect when such basis differences reverse. Valuation allowances are established, if necessary, to reduce the deferred tax asset to the amount that will, more likely than not, be realized.
Concentration of Credit Risk	Concentration of Credit Risk. Financial instruments that subject the Company to credit risk consist of cash and cash equivalents and certificates of deposit. The Company maintains cash and cash equivalents and certificates of deposit with well-capitalized financial institutions. At times, those amounts may exceed federally insured limits. The Company has no significant concentrations of credit risk.
Stock-Based Compensation	Stock-Based Compensation. Stock-based compensation cost is measured at the grant date based on the fair value of the award and is recognized as expense over the service period, which generally represents the vesting period. For awards that have performance-based vesting conditions the Company recognizes the expense over the estimated period that the awards are expected to be earned. The Company generally uses the Black-Scholes option-pricing model to calculate the grant date fair value of stock options. The expense recognized over the service period is required to include an estimate of the awards that will be forfeited.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards . In December 2019, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This standard will be effective for the Company’s interim and annual periods beginning with the first quarter of fiscal 2021 and must be applied on a modified retrospective basis. This standard will not materially impact the Company’s consolidated financial statements.

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property and Equipment

Property and equipment consist of the following at December 31:


	2020			2019
	(in thousands)
Leasehold improvements	$	2		$	2
Computer and office equipment		13			13
Furniture and fixtures		59			59

Total		74			74
Less accumulated depreciation and amortization		(74	)		(74	)

Property and equipment — net	$	—		$	—

Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2020

Accrued Expenses

Accrued expenses consist of the following at December 31:


	2020		2019
	(in thousands)
Legal and accounting fees	$	122	$	81
Accrued compensation		789		973
Lease liability		44		39
Accrued research and development costs and other		3,087		—

Total	$	4,042	$	1,093

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2020

Return on Investment

ROI Percentage shall mean the percentage that applies as of the redemption date, as follows:

ROI Percentage


200%		before the second anniversary of the date of issuance;
250%		on or after the second anniversary of the date of issuance, but before the third anniversary of the date of issuance;


300%		on or after the third anniversary of the date of issuance, but before the fourth anniversary of the date of issuance;
350%		on or after the fourth anniversary of the date of issuance, but before the fifth anniversary of the date of issuance;
400%		on or after the fifth anniversary of the date of issuance, but before the sixth anniversary of the date of issuance;
450%		on or after the sixth anniversary of the date of issuance, but before the seventh anniversary of the date of issuance;
500%		on or after the seventh anniversary of the date of issuance, but before the eighth anniversary of the date of issuance; and
550%		on or after the eighth anniversary of the date of issuance, but before the ninth anniversary of the date of issuance.

Warrants (Tables)

12 Months Ended

Dec. 31, 2020

Summary of Information with Regard to Outstanding Warrants Issued in Connection with Equity and Debt Financings and Consultants

Warrant activity is summarized as follows:


Outstanding at December 31, 2018	10,647,026
Issued	2,622,154
Exercised	(730,976	)
Canceled	—

Outstanding at December 31, 2019	12,538,204

Issued	—
Exercised	—
Canceled	—

Outstanding at December 31, 2020	12,538,204

The following table summarizes information with regard to outstanding warrants issued in connection with equity and debt financings and consultants as of December 31, 2020.


Issued in Connection With	Number Issued		Exercise Price		Exercisable Date		Expiration Date
February 12, 2009 Series B-1 Transaction $3.00 Investor Warrants — Class B		1,200,000	$	3.00		February 12, 2009		February 12, 2024
May 13, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		600,000	$	3.00		May 13, 2009		May 13, 2024
June 30, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		333,333	$	3.00		June 30, 2009		June 30, 2024
August 12, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		200,000	$	3.00		August 12, 2009		August 12, 2024
September 30, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		216,666	$	3.00		September 30, 2009		September 30, 2024


Issued in Connection With	Number Issued		Exercise Price		Exercisable Date		Expiration Date
November 4, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		106,666	$	3.00		November 4, 2009		November 4, 2024
December 8, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B		133,143	$	3.00		December 8, 2009		December 8, 2024
January 29, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B		216,667	$	3.00		January 29, 2010		January 29, 2025
March 8, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B		223,334	$	3.00		March 8, 2010		March 8, 2025
April 30, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B		204,192	$	3.00		April 30, 2010		April 30, 2025
May 10, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B		143,166	$	3.00		May 10, 2010		May 10, 2025
November 25, 2015 Offering Warrants		1,180,240	$	2.50		May 25, 2016		May 25, 2021
September 22, 2016 Series B-3 Transaction $3.00 Investor Warrants		698,158	$	3.00		September 22, 2016		September 22, 2023
September 29, 2016 Series B-3 Transaction $3.00 Investor Warrants		846,100	$	3.00		September 29, 2016		September 29, 2023
December 22, 2016 Private placement warrants		1,466,204	$	5.00		December 22, 2016		December 23, 2023
December 23, 2016 Series B-3 Transaction $3.00 Investor Warrants		924,780	$	3.00		December 23, 2016		December 23, 2023
December 28, 2016 Private placement warrants		644,468	$	5.00		December 28, 2016		December 28, 2023
February 27, 2017 Private placement warrants		76,776	$	5.00		February 27, 2017		February 27, 2024
2018 and 2017 Warrants issued for services		2,157	$	5.00		Various dates in 2018 and 2017		Various dates in 2025 and 2024
December 19, 2017 Line of credit warrants		500,000	$	5.00		December 19, 2017		December 19, 2024
May 23, 2019 Rights offering warrants		2,622,154	$	7.00		May 23, 2019		May 23, 2026

Total outstanding warrants		12,538,204

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Stock-Based Compensation Expense Related to Common Stock Options, Restricted Common Stock and Common Stock Warrants

Following is the stock-based compensation expense related to common stock options, restricted common stock, common stock warrants and deferred stock units:


	Year Ended December 31,
	2020		2019
Research and development	$	516	$	318
General and administrative		1,283		1,365

Total stock-based compensation expense	$	1,799	$	1,683

Weighted Average Assumptions Used to Determine Fair Value of Options Granted

The fair value of the options granted is determined using the Black-Scholes option-pricing model. The following weighted average assumptions were used:


	2020			2019
Risk-free interest rate		1.26	%		2.68	%
Expected life of the options		6.0 years			6.0 years
Expected volatility of the underlying stock		97.9	%		103.7	%
Expected dividend rate		0	%		0	%

Summary of Stock Option Activity

The following table summarizes the stock option activity in the stock-based compensation plans:


	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2018		2,713,979		$	4.67
Granted		530,000			4.72
Forfeited/Cancelled		(92,730	)		2.91
Exercised		(150,993	)		1.83

Outstanding, December 31, 2019		3,000,256		$	4.88
Granted		1,095,000			2.51
Forfeited/Cancelled		(834	)		1.80
Exercised		(106,847	)		2.61

Outstanding, December 31, 2020		3,987,575		$	4.29		6.34	$	450

Exercisable, December 31, 2020		3,335,908		$	4.68		5.75	$	303

Summary of Additional Information Regarding Outstanding and Exercisable Options under Stock Based Compensation Plans

The following table summarizes additional information regarding outstanding and exercisable options under our stock-based compensation plans at December 31, 2020:


	Options Outstanding						Options Exercisable
Exercise Price (Range)	Number of Shares		Weighted Average Remaining Contractual Life		Weighted Average Exercise Price		Number of Shares		Weighted Average Exercise Price
			(in years)
$0.87 – 1.00		190,500		5.95	$	0.88		190,500	$	0.88
$1.01 – 3.00		1,683,060		7.81		2.47		1,031,393		2.60
$3.01 – 5.00		1,053,040		7.17		4.35		1,053,040		4.35
$5.01 – 8.00		878,475		3.27		6.55		878,475		6.55
$8.01 – 13.38		182,500		3.06		13.38		182,500		13.38

		3,987,575		6.34	$	4.29		3,335,908	$	4.68

Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2020

Computation of Diluted Net Loss Per Share does not Assume Issuance of Common Shares that have an Anti-dilutive Effect on Net Loss Per Share

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.


	Year Ended December 31,
	(in thousands, except per share amounts)
	2020		2019
Net loss		$ (23,465)		$ (13,294)
Preferred stock dividends		(137)		(263)
Warrant modification		—		(6,622)

Net loss applicable to common stockholders		$ (23,602)		$ (20,179)

Basic and diluted net loss per share		$ (0.41)		$ (0.39)
Shares used in computing basic and diluted net loss per share		57,029		52,238

Dilutive Shares Which Could Exist Pursuant to Exercise of Outstanding Stock Instruments and Which were not Included in Calculation


	Year Ended December 31,
	2020 (Shares)		2019 (Shares)
Warrants to purchase shares of common stock		12,538,204		12,538,204
Options to purchase shares of common stock		3,987,575		3,000,256
Shares of common stock issuable upon conversion preferred stock		510,424		514,590

		17,036,203		16,053,050

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2020

Maturity of operating lease

Maturity of operating lease as of December 31, 2020 in thousands:


2021	$	48
2022		8

Total		56

Less imputed interest		4

Present value of lease liability	$	52

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Components of Net Deferred Tax Assets

The components of the net deferred tax assets are as follows at December 31:


	2020			2019
	(in thousands)
Operating loss carryforwards	$	46,203		$	39,982
Tax credit carryforwards		910			910
Other temporary differences		5,438			5,278

	52,551			46,170
Less valuation allowance		(52,551	)		(46,170	)

Net deferred tax asset	$	—		$	—

Primary Factors Affecting Income Tax Rates

The primary factors affecting the Company’s income tax rates were as follows:


	2020			2019
Tax benefit at U.S. statutory rates		(21	%)		(21	%)
State tax benefit		(4.7	%)		(4.7	%)
Permanent differences		0.8	%		0.8	%
Impact of the 2017 Tax Act		—			—
Other		(2.2	%)		(4.2	%)
Expiring state NOL’s		—			—
Changes in valuation allowance		27.1	%		29.1	%

	0		%	0		%

Nature of Business, Basis of Presentation and Liquidity - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basis of Presentation [Line Items]
Unrestricted cash and cash equivalents	$ 27,142	$ 47,480	$ 8,253
Maximum
Basis of Presentation [Line Items]
Currently estimated costs of trail and general overhead	50,000
Minimum
Basis of Presentation [Line Items]
Currently estimated costs of trail and general overhead	$ 45,000

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Significant Accounting Policies [Line Items]
Cash equivalents	$ 0	$ 0
Security deposit for leased office space	6,000	6,000
Impairment of long-lived assets	0	0
Level 2
Significant Accounting Policies [Line Items]
Fair value of assets	0	0
Fair value of liabilities	0	0
Level 3
Significant Accounting Policies [Line Items]
Fair value of assets	0	0
Fair value of liabilities	$ 0	$ 0
Computer and office equipment
Significant Accounting Policies [Line Items]
Estimated useful lives of property and equipment	3 years
Furniture and fixtures
Significant Accounting Policies [Line Items]
Estimated useful lives of property and equipment	5 years

Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 74	$ 74
Less accumulated depreciation and amortization	(74)	(74)
Property and equipment-net
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2	2
Computer and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	13	13
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 59	$ 59

Property and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 0	$ 0

Accrued Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule of Accrued Liabilities [Line Items]
Legal and accounting fees	$ 122	$ 81
Accrued compensation	789	973
Lease liability	44	39
Accrued research and development costs and other	3,087
Total	$ 4,042	$ 1,093
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OperatingLeaseLiability

Stockholders' Equity - Additional Information (Detail)									1 Months Ended					12 Months Ended							16 Months Ended
Stockholders' Equity - Additional Information (Detail)	May 23, 2019 USD ($) yr $ / shares	Apr. 29, 2019 USD ($) $ / shares shares	Jan. 11, 2019 shares	Dec. 23, 2016 USD ($) shares	Sep. 22, 2016 USD ($) shares	Dec. 30, 2010 USD ($) $ / shares shares	Feb. 12, 2009 USD ($) shares	Feb. 04, 2008 $ / shares	Jun. 30, 2020 USD ($) shares	May 31, 2020	Jan. 31, 2019 USD ($) yr shares	Jul. 31, 2011 shares	Jan. 31, 2011 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 shares	Dec. 31, 2017 shares	Dec. 31, 2014 shares	Dec. 31, 2013 shares	Dec. 31, 2011 USD ($) $ / shares shares	May 31, 2010 shares	May 11, 2020 USD ($)	Jan. 01, 2019 shares	May 19, 2017 USD ($)	Dec. 29, 2010 $ / shares
Class of Stock [Line Items]
Common stock, shares authorized														100,000,000	100,000,000
Undesignated stock, shares authorized														20,000,000	20,000,000
Net proceeds from issuance of common stock \| $														$ 263,000	$ 50,469,000
Warrants issued						500	6,000,000				3,579,642
Exercise price of warrant \| $ / shares						$ 7.20
Fair market value of common stock per share \| $ / shares	$ 4.01													$ 2.24
Minimum closing price of the common stock to require conversion \| $ / shares																				$ 18.00
Stock issuance costs \| $						$ 47,000
Preferred stock issuable							3,000,000
Preferred stock value \| $							$ 6,000,000.0
Common shares issuable upon conversion of preferred stock							2,000,000													1,667
Number of shares agreed to issue and sell				1,008,000
Liquidation preference per share after series A preferred stock \| $ / shares						$ 10,000
Preferred stock, par value \| $ / shares																									$ 0.01
Recognition of non cash charge related to extension of warrants \| $											$ 6,622,000,000			$ 0	$ 6,622,000
Warrants Exercised														500,000									3,579,642
Price per warrants class \| $ / shares						$ 7.20
Measurement Input, Price Volatility [Member] \| Before Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability											98
Measurement Input, Price Volatility [Member] \| After Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability											106
Measurement Input, Expected Dividend Rate \| Before Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability															0
Measurement Input, Expected Dividend Rate \| After Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability															0
Series A Preferred Stock
Class of Stock [Line Items]
Stock price per share \| $ / shares								$ 9.00
Number of consecutive trading days prior to dividend payment date								20 days
Series A One Warrant
Class of Stock [Line Items]
Number of consecutive trading days prior to dividend payment date								15 days
Maximum \| Minimum expected life range [member] \| Before Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability \| yr											1.33
Maximum \| Minimum expected life range [member] \| After Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability \| yr											6.33
Maximum \| Measurement Input, Risk Free Interest Rate [Member] \| Before Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability											2.59
Maximum \| Measurement Input, Risk Free Interest Rate [Member] \| After Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability											2.6
Minimum \| Minimum expected life range [member] \| Before Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability \| yr											5.09
Minimum \| Minimum expected life range [member] \| After Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability \| yr											0.09
Minimum \| Measurement Input, Risk Free Interest Rate [Member] \| Before Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability											2.4
Minimum \| Measurement Input, Risk Free Interest Rate [Member] \| After Modification of Terms of Warrants [Member]
Class of Stock [Line Items]
Derivative liability											2.56
Warrant [Member]
Class of Stock [Line Items]
Exercise price of warrant \| $ / shares		$ 7.00
Issuance of warrants, value \| $	$ 8,200,000
Termination notice period																				30 days
Price per warrants class \| $ / shares		$ 7.00
Warrant [Member] \| Measurement Input, Price Volatility [Member]
Class of Stock [Line Items]
Fair value assumptions, Measurement Input	101
Warrant [Member] \| Measurement Input, Risk Free Interest Rate [Member]
Class of Stock [Line Items]
Fair value assumptions, Measurement Input	2.33
Warrant [Member] \| Measurement Input, Expected Term [Member]
Class of Stock [Line Items]
Fair value assumptions, Measurement Input \| yr	7
Series B-1 12% convertible preferred stock
Class of Stock [Line Items]
Convertible stock conversion ratio								12
Series B-2 12% convertible preferred stock
Class of Stock [Line Items]
Series A 12% convertible preferred stock, shares authorized														2,100,000
Series B-2 12% convertible preferred stock \| Maximum
Class of Stock [Line Items]
Convertible preferred stock dividend \| $																				$ 100,000
Series C 6% super dividend redeemable convertible preferred stock
Class of Stock [Line Items]
Convertible preferred stock, shares authorized														1,000	1,000
Shares of common stock issued						212							13
Preferred stock, dividend rate																				6.00%
Stock price per share \| $ / shares						$ 10,000							$ 10,000
Number of consecutive trading days for conversion of preferred stock																				15 days
Aggregate stated value and proceeds \| $						$ 2,120,000
Liquidation preference per share after series A preferred stock \| $ / shares																				$ 10,000
Proceeds from issuance of preferred stock, net \| $						$ 2,073,000							$ 130,000
Common stocks issued upon conversion of Preferred Stock																293,340	293,340	33,756	40,193	8,334
Post conversion dividend rights issued												5						20	24
Post conversion redemption right, return on investment multiplier amount \| $																				$ 10,000
Preferred stock redemption price \| $ / shares																				$ 3.00
Convertible preferred stock, redemption value \| $														$ 8,546,000
Issuance of common stock (in shares)						212							13
Series C 6% super dividend redeemable convertible preferred stock \| Series A Preferred Stock
Class of Stock [Line Items]
Dividend as percentage of net sales																				2.50%
Series C 6% super dividend redeemable convertible preferred stock \| Series B One Preferred Stock
Class of Stock [Line Items]
Dividend as percentage of net sales																				1.25%
Series B-3 8% convertible preferred stock
Class of Stock [Line Items]
Series A 12% convertible preferred stock, shares authorized														2,508,000
Series A 12% convertible preferred stock
Class of Stock [Line Items]
Series A 12% convertible preferred stock, shares authorized														1,742,500
Preferred stock, dividend rate								12.00%						12.00%
Stock price per share \| $ / shares								$ 6.00
Dividend, percentage of value weighted average share price								100.00%
Conversion of Series A Convertible Preferred to common																	410,000
Series A 12% convertible preferred stock \| Scenario 2
Class of Stock [Line Items]
Stock price per share \| $ / shares								$ 12.00
Series A 12% convertible preferred stock \| Minimum
Class of Stock [Line Items]
Minimum closing price of the common stock to require conversion \| $ / shares								$ 18.00
Series B-1 12% convertible preferred stock
Class of Stock [Line Items]
Series A 12% convertible preferred stock, shares authorized														900,000
Shares of common stock issued																					900,000
Warrants issued																					1,800,000
Issuance of common stock (in shares)																					900,000
Series B-2 12% convertible preferred stock
Class of Stock [Line Items]
Shares of common stock issued																					2,100,000
Preferred stock issuable							3,000,000
Common shares issuable upon conversion of preferred stock							2,000,000
Convertible preferred shares														25,000
Common stocks issued upon conversion of Preferred Stock														4,553
shares relating to prorated dividend prior conversion														387
Issuance of common stock (in shares)																					2,100,000
Common Stock [Member]
Class of Stock [Line Items]
Convertible preferred stock, shares authorized														12,748,500
Shares of common stock issued		10,488,161
Net proceeds from issuance of common stock \| $		$ 44,900,000
Conversion of Series A Convertible Preferred to common																	69,312
Warrants Exercised		2,622,154
Issuance of common stock (in shares)		10,488,161
B Three Securities Purchase Agreement
Class of Stock [Line Items]
Warrants to purchase common stock issued in agreeing not to sell any share for 18 months					875,000
B Three Securities Purchase Agreement \| Maximum
Class of Stock [Line Items]
Warrants to purchase common stock					669,262
B Three Securities Purchase Agreement \| Series B-3 8% convertible preferred stock
Class of Stock [Line Items]
Number of shares agreed to issue and sell					1,500,000
Aggregate stated value and proceeds \| $					$ 1,500,000
Number of common stock issued upon conversion					892,349
2017 At Market Agreement
Class of Stock [Line Items]
Aggregate offering price \| $																								$ 30,000,000.0
Commission to sales agent as a percentage of gross proceeds																								3.00%
Shares of common stock issued														0	662,459
Net proceeds from issuance of common stock \| $														$ 2,930,000
Issuance of common stock (in shares)														0	662,459
Description of Termination of Market Agreement										the 2017 At Market Agreement was terminated in May 2020.
Amended B Three Securities Purchase Agreement \| Maximum
Class of Stock [Line Items]
Warrants to purchase common stock				924,780
Amended B Three Securities Purchase Agreement \| Series B-3 8% convertible preferred stock
Class of Stock [Line Items]
Number of shares agreed to issue and sell				1,008,000
Aggregate stated value and proceeds \| $				$ 1,000,000.0
Number of common stock issued upon conversion				896,997
2020 At Market Agreement
Class of Stock [Line Items]
Aggregate offering price \| $																						$ 40,000,000.0
Commission to sales agent as a percentage of gross proceeds																						3.00%
Shares of common stock issued									14,452
Net proceeds from issuance of common stock \| $									$ 44,000
Issuance of common stock (in shares)									14,452
Ten X Fund LP [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Common stocks issued upon conversion of Preferred Stock			3,789,346
Ten X Fund LP [Member] \| Series B1 B2 and B3 Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Convertible preferred shares			5,508,000

Return on Investment (Detail)	12 Months Ended
Return on Investment (Detail)	Dec. 31, 2020
Class of Stock [Line Items]
ROI Percentage	300.00%
Period 1
Class of Stock [Line Items]
ROI Percentage	200.00%
Redemption date	before the second anniversary of the date of issuance;
Period 2
Class of Stock [Line Items]
ROI Percentage	250.00%
Redemption date	on or after the second anniversary of the date of issuance, but before the third anniversary of the date of issuance;
Period 3
Class of Stock [Line Items]
Redemption date	on or after the third anniversary of the date of issuance, but before the fourth anniversary of the date of issuance;
Period 4
Class of Stock [Line Items]
ROI Percentage	350.00%
Redemption date	on or after the fourth anniversary of the date of issuance, but before the fifth anniversary of the date of issuance;
Period 5
Class of Stock [Line Items]
ROI Percentage	400.00%
Redemption date	on or after the fifth anniversary of the date of issuance, but before the sixth anniversary of the date of issuance;
Period 6
Class of Stock [Line Items]
ROI Percentage	450.00%
Redemption date	on or after the sixth anniversary of the date of issuance, but before the seventh anniversary of the date of issuance;
Period 7
Class of Stock [Line Items]
ROI Percentage	500.00%
Redemption date	on or after the seventh anniversary of the date of issuance, but before the eighth anniversary of the date of issuance; and
Period 8
Class of Stock [Line Items]
ROI Percentage	550.00%
Redemption date	on or after the eighth anniversary of the date of issuance, but before the ninth anniversary of the date of issuance.

Summary of Warrant Activity (Detail) - Warrant - shares	12 Months Ended
Summary of Warrant Activity (Detail) - Warrant - shares	Dec. 31, 2020	Dec. 31, 2019
Shares
Beginning Balance	12,538,204	10,647,026
Issued		2,622,154
Exercised		(730,976)
Cancelled	0
Ending Balance	12,538,204	12,538,204

Summary of Information with Regard to Outstanding Warrants Issued in Connection with Equity and Debt Financing and Consultants (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 30, 2010
Equity [Line Items]
Number Issued	12,538,204
Exercise Price		$ 7.20
February 12, 2009 Series B-1 Transaction
Equity [Line Items]
Exercisable Date	February 12, 2009
Number Issued	1,200,000
Exercise Price	$ 3.00
Expiration Date	Feb. 12, 2024
May 13, 2009 Series B-2 Transaction
Equity [Line Items]
Exercisable Date	May 13, 2009
Number Issued	600,000
Exercise Price	$ 3.00
Expiration Date	May 13, 2024
June 30, 2009 Series B-2 Transaction
Equity [Line Items]
Exercisable Date	June 30, 2009
Number Issued	333,333
Exercise Price	$ 3.00
Expiration Date	Jun. 30, 2024
August 12, 2009 Series B-2 Transaction
Equity [Line Items]
Exercisable Date	August 12, 2009
Number Issued	200,000
Exercise Price	$ 3.00
Expiration Date	Aug. 12, 2024
September 30, 2009 Series B-2 Transaction
Equity [Line Items]
Exercisable Date	September 30, 2009
Number Issued	216,666
Exercise Price	$ 3.00
Expiration Date	Sep. 30, 2024
November 4, 2009 Series B-2 Transaction
Equity [Line Items]
Exercisable Date	November 4, 2009
Number Issued	106,666
Exercise Price	$ 3.00
Expiration Date	Nov. 04, 2024
December 8, 2009 Series B-2 Transaction
Equity [Line Items]
Exercisable Date	December 8, 2009
Number Issued	133,143
Exercise Price	$ 3.00
Expiration Date	Dec. 08, 2024
January 29, 2010 Series B-2 Transaction
Equity [Line Items]
Number Issued	216,667
Exercise Price	$ 3.00
Exercisable Date	Jan. 29, 2010
Expiration Date	Jan. 29, 2025
March 8, 2010 Series B-2 Transaction
Equity [Line Items]
Number Issued	223,334
Exercise Price	$ 3.00
Exercisable Date	Mar. 08, 2010
Expiration Date	Mar. 08, 2025
April 30, 2010 Series B-2 Transaction
Equity [Line Items]
Number Issued	204,192
Exercise Price	$ 3.00
Exercisable Date	Apr. 30, 2010
Expiration Date	Apr. 30, 2025
May 10, 2010 Series B-2 Transaction
Equity [Line Items]
Number Issued	143,166
Exercise Price	$ 3.00
Exercisable Date	May 10, 2010
Expiration Date	May 10, 2025
November 25, 2015 Offering Warrants
Equity [Line Items]
Number Issued	1,180,240
Exercise Price	$ 2.50
Exercisable Date	May 25, 2016
Expiration Date	May 25, 2021
September 22, 2016 Series B-3 Transaction
Equity [Line Items]
Expiration Date	September 22, 2023
Number Issued	698,158
Exercise Price	$ 3.00
Exercisable Date	Sep. 22, 2016
September 29, 2016 Series B-3 Transaction
Equity [Line Items]
Number Issued	846,100
Exercise Price	$ 3.00
Exercisable Date	Sep. 29, 2016
Expiration Date	Sep. 29, 2023
December 22, 2016 Private Placement Warrants
Equity [Line Items]
Number Issued	1,466,204
Exercise Price	$ 5.00
Exercisable Date	Dec. 22, 2016
Expiration Date	Dec. 23, 2023
December 23, 2016 Series B-3 Transaction
Equity [Line Items]
Number Issued	924,780
Exercise Price	$ 3.00
Exercisable Date	Dec. 23, 2016
Expiration Date	Dec. 23, 2023
December 28, 2016 Private Placement Warrants
Equity [Line Items]
Expiration Date	December 28, 2023
Number Issued	644,468
Exercise Price	$ 5.00
Exercisable Date	Dec. 28, 2016
February 27, 2017 Private Placement Warrants
Equity [Line Items]
Number Issued	76,776
Exercise Price	$ 5.00
Exercisable Date	Feb. 27, 2017
Expiration Date	Feb. 27, 2024
2018 and 2017 Warrants issued for services
Equity [Line Items]
Exercisable Date	Various dates in 2018 and 2017
Expiration Date	Various dates in 2025 and 2024
Number Issued	2,157
Exercise Price	$ 5.00
December 19, 2017 Line of Credit Warrants
Equity [Line Items]
Number Issued	500,000
Exercise Price	$ 5.00
Exercisable Date	Dec. 19, 2017
Expiration Date	Dec. 19, 2024
May 23, 2019 Rights offering warrants
Equity [Line Items]
Number Issued	2,622,154
Exercise Price	$ 7.00
Exercisable Date	May 23, 2019
Expiration Date	May 23, 2026

Summary of Information with Regard to Outstanding Warrants Issued in Connection with Equity and Debt Financing and Consultants (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2020 $ / shares
February 12, 2009 Series B-1 Transaction
Equity [Line Items]
Warrant issuance date	Feb. 12, 2009
Warrant issued price per share	$ 3.00
May 13, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	May 13, 2009
Warrant issued price per share	$ 3.00
June 30, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Jun. 30, 2009
Warrant issued price per share	$ 3.00
August 12, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Aug. 12, 2009
Warrant issued price per share	$ 3.00
September 30, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Sep. 30, 2009
Warrant issued price per share	$ 3.00
November 4, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Nov. 04, 2009
Warrant issued price per share	$ 3.00
December 8, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Dec. 08, 2009
Warrant issued price per share	$ 3.00
January 29, 2010 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Jan. 29, 2010
Warrant issued price per share	$ 3.00
March 8, 2010 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Mar. 08, 2010
Warrant issued price per share	$ 3.00
April 30, 2010 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Apr. 30, 2010
Warrant issued price per share	$ 3.00
May 10, 2010 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	May 10, 2010
Warrant issued price per share	$ 3.00
November 25, 2015 Offering Warrants
Equity [Line Items]
Warrant issuance date	Nov. 25, 2015
September 22, 2016 Series B-3 Transaction
Equity [Line Items]
Warrant issuance date	Sep. 22, 2016
Warrant issued price per share	$ 3.00
September 29, 2016 Series B-3 Transaction
Equity [Line Items]
Warrant issuance date	Sep. 29, 2016
Warrant issued price per share	$ 3.00
December 22, 2016 Private Placement Warrants
Equity [Line Items]
Warrant issuance date	Dec. 22, 2016
Warrant issued price per share	$ 3.00
December 23, 2016 Series B-3 Transaction
Equity [Line Items]
Warrant issuance date	Dec. 23, 2016
December 28, 2016 Private Placement Warrants
Equity [Line Items]
Warrant issuance date	Dec. 28, 2016
February 27, 2017 Private Placement Warrants
Equity [Line Items]
Warrant issuance date	Feb. 27, 2017
December 19, 2017 Line of Credit Warrants
Equity [Line Items]
Warrant issuance date	Dec. 19, 2017
May 23, 2019 Rights offering warrants
Equity [Line Items]
Warrant issuance date	May 23, 2019

Stock-Based Compensation - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	May 23, 2019	Jan. 31, 2019	Dec. 31, 2018	May 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-plan grants outstanding	3,987,575	3,000,256			2,713,979
Expected life	6 years	6 years
Expected dividend yield used in the option valuation model	0.00%	0.00%
Common stock price	$ 2.24		$ 4.01
Weighted-average grant-date fair values of options granted	$ 1.92	$ 3.83
Unvested option	651,667			407,500
Unrecognized compensation cost	$ 1,052,000
Unrecognized compensation cost, recognition period	2 years 6 months 10 days
Options vested	850,833	130,490
Total fair value of options vested	$ 2,531,758	$ 491,000
Number of options granted	1,095,000	530,000
Intrinsic value of stock options	$ 39,792	$ 594,302
Non Qualified Options Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-plan stock option grants to employees and non-employees	1,477,379
Non-plan grants outstanding	500,000
Incentive Compensation Plan 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common stock for issuance upon exercise of grants	4,000,000					6,733,334
Stock awards, available for future grant	2,822,000
Number of options granted	0
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	5 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	10 years
Chief Executive Officer [Member] \| Deferred Bonus [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 0
Description of Outstanding Shares of Deferred Stock Units Issued to Chief Executive Officer Terms	The Company shall issue the shares underlying the outstanding whole number of DSUs credited to Mr. Lewis as follows: twenty five percent shall be issued on March 1, 2023, twenty five percent shall be issued on September 1, 2023 and fifty percent shall be issued on March 1, 2024.
Stock Based Compensation Expense	$ 132,000
Common stock reserved for future issuance	50,307
Common Stock Weighted average Grant Date fair Value	$ 2.62
Chief Executive Officer [Member] \| Deferred Profit Sharing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of base salary paid in cash	20.00%
Percentage of base salary paid in deferred stock units	80.00%
Restricted Stock \| Non Employees Seven Board Of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards granted		19,068
Amortized expense		$ 90,000
Restricted Stock \| Non Employees Two Board Of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards granted	32,693
Amortized expense	$ 94,000

Stock-Based Compensation Expense Related to Common Stock Options, Restricted Common Stock and Common Stock Warrants (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,799	$ 1,683
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	516	318
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,283	$ 1,365

Weighted Average Assumptions Used to Determine Fair Value of Options Granted (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.26%	2.68%
Expected life of the options	6 years	6 years
Expected volatility of the underlying stock	97.90%	103.70%
Expected dividend rate	0.00%	0.00%

Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Shares
Beginning Balance	3,000,256	2,713,979
Granted	1,095,000	530,000
Forfeited/Cancelled	(834)	(92,730)
Exercised	(106,847)	(150,993)
Ending Balance	3,987,575	3,000,256
Exercisable, December 31, 2020	3,335,908
Weighted Average Exercise Price
Beginning Balance	$ 4.88	$ 4.67
Granted	2.51	4.72
Forfeited/Cancelled	1.80	2.91
Exercised	2.61	1.83
Ending Balance	4.29	$ 4.88
Exercisable, December 31, 2020	$ 4.68
Weighted Average Remaining Contractual Life (Years)
Outstanding, December 31, 2020	6 years 4 months 2 days
Exercisable, December 31, 2020	5 years 9 months
Stock Options Aggregate Intrinsic Value
Outstanding, December 31, 2020	$ 450
Exercisable, December 31, 2020	$ 303

Summary of Additional Information Regarding Outstanding and Exercisable Options under Stock Based Compensation Plans (Detail)	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Number of Shares \| shares	3,987,575
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 4 months 2 days
Options Outstanding, Weighted Average Exercise Price	$ 4.29
Options Exercisable, Number of Shares \| shares	3,335,908
Options Exercisable, Weighted Average Exercise Price	$ 4.68
$0.87-$1.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Exercise Price	0.87
Maximum Exercise Price	$ 1.00
Options Outstanding, Number of Shares \| shares	190,500
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 11 months 12 days
Options Outstanding, Weighted Average Exercise Price	$ 0.88
Options Exercisable, Number of Shares \| shares	190,500
Options Exercisable, Weighted Average Exercise Price	$ 0.88
$1.01-$3.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Exercise Price	1.01
Maximum Exercise Price	$ 3.00
Options Outstanding, Number of Shares \| shares	1,683,060
Options Outstanding, Weighted Average Remaining Contractual Life	7 years 9 months 21 days
Options Outstanding, Weighted Average Exercise Price	$ 2.47
Options Exercisable, Number of Shares \| shares	1,031,393
Options Exercisable, Weighted Average Exercise Price	$ 2.60
$3.01-$5.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Exercise Price	3.01
Maximum Exercise Price	$ 5.00
Options Outstanding, Number of Shares \| shares	1,053,040
Options Outstanding, Weighted Average Remaining Contractual Life	7 years 2 months 1 day
Options Outstanding, Weighted Average Exercise Price	$ 4.35
Options Exercisable, Number of Shares \| shares	1,053,040
Options Exercisable, Weighted Average Exercise Price	$ 4.35
$5.01 - $8.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Exercise Price	5.01
Maximum Exercise Price	$ 8.00
Options Outstanding, Number of Shares \| shares	878,475
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 3 months 7 days
Options Outstanding, Weighted Average Exercise Price	$ 6.55
Options Exercisable, Number of Shares \| shares	878,475
Options Exercisable, Weighted Average Exercise Price	$ 6.55
$8.01-$13.38
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Exercise Price	8.01
Maximum Exercise Price	$ 13.38
Options Outstanding, Number of Shares \| shares	182,500
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 21 days
Options Outstanding, Weighted Average Exercise Price	$ 13.38
Options Exercisable, Number of Shares \| shares	182,500
Options Exercisable, Weighted Average Exercise Price	$ 13.38

Line of Credit - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Apr. 29, 2019	Jan. 31, 2019	Jan. 01, 2019	Dec. 30, 2010
Line of Credit Facility [Line Items]
Number of securities called by warrant	500,000				3,579,642
Exercise price of warrant						$ 7.20
Warrant value	$ 696,000
Expected life	6 years	6 years
Expected Volatility	97.90%	103.70%
Expected dividend	0.00%	0.00%
Risk free interest rate	1.26%	2.68%
Amortization of interest expense	$ 87,000	$ 87,000
Unsecured Line Of Credit \| Director
Line of Credit Facility [Line Items]
Line of credit facility				$ 10,000,000
Short term borrowing interest rate	0.14%
Number of securities called by warrant	1,000,000
Exercise price of warrant	$ 5
Line of credit current	$ 0
Line of Credit Facility Current Borrowing Capacity	$ 10,000,000
Warrant
Line of Credit Facility [Line Items]
Exercise price of warrant			$ 7.00
Expected life	7 years
Expected Volatility	98.00%
Expected dividend	0.00%
Risk free interest rate	2.05%

Computation of Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Computation Of Basic And Diluted Earnings Per Common Share [Line Items]
Net loss	$ (23,465)	$ (13,294)
Preferred stock dividends	(137)	(263)
Warrant modification		(6,622)
Net loss applicable to common stockholders	$ (23,602)	$ (20,179)
Basic and diluted net loss per share	$ (0.41)	$ (0.39)
Shares used in computing basic and diluted net loss per share	57,029	52,238

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669625-108580

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794

+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1448-109256

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1377-109256

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

+ Details

Dilutive Shares Which Could Exist Pursuant to Exercise of Outstanding Stock Instruments and Which were not Included in Calculation (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive shares not included in calculation	17,036,203	16,053,050
Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive shares not included in calculation	12,538,204	12,538,204
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive shares not included in calculation	3,987,575	3,000,256
Contingently Issuable Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive shares not included in calculation	510,424	514,590

Commitments and Contingencies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Commitment And Contingencies [Line Items]
Lessee, Operating Lease, Term of Contract			38 months
Lease Deposits			$ 6,000
Lease liability	$ 44,000	$ 39,000
Discount rate	11.04%
Other assets
Commitment And Contingencies [Line Items]
Right-of-Use Asset	$ 48,000
Accrued And Other Liabilities Current
Commitment And Contingencies [Line Items]
Lease liability	44,000
Other liabilities
Commitment And Contingencies [Line Items]
Non current lease liability	8,000
General and administrative
Commitment And Contingencies [Line Items]
Lease cost	$ 44,000	$ 44,000

Commitments and Contingencies - Maturity of operating lease (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2021	$ 48
2022	8
Total	56
Less imputed interest	4
Present value of lease liability	$ 52
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OperatingLeaseLiability

Galectin Science LLC - Additional Information (Detail) - Galectin Sciences, LLC - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended			24 Months Ended	36 Months Ended
	Jan. 31, 2014	Dec. 31, 2014	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2014	Dec. 31, 2017	Dec. 31, 2017
Investments in and Advances to Affiliates [Line Items]
Equity method investment in Galectin Sciences LLC	$ 400,000
Subsequent capital contribution		$ 73,000	$ 448,000	$ 147,000			$ 1,711,000
Equity Method Investment, Ownership Percentage	50.00%
Loss from equity method investment in Galectin Sciences, LLC					$ 400,000
Non-cash charge for in-process research and development					200,000
Proceeds from Sale of Equity Method Investments					$ 400,000
SBH Sciences, Inc
Investments in and Advances to Affiliates [Line Items]
Subsequent capital contribution			$ 35,000			$ 123,000
SBH Sciences, Inc \| In Process Research and Development
Investments in and Advances to Affiliates [Line Items]
Estimated fair value of the IPR&D Contributed by SBH	$ 400,000
Ownership Percentage			83.40%

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Statutory federal income tax rate	21.00%	21.00%	21.00%	34.00%
Benefits related to stock options	$ 2,120,000
Deferred tax asset valuation allowance percentage in each of the last two years	100.00%
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Net operating loss carryforwards	$ 136,202,000
Operating loss carryforwards, expiration year	2037
Research and development credits	$ 733,000
Research and development credits, expiration year	2034
State and Local Jurisdiction
Income Taxes [Line Items]
Net operating loss carryforwards	$ 138,676,000
Operating loss carryforwards, expiration year	2037
Research and development credits	$ 176,000
Research and development credits, expiration year	2034
State and Local Jurisdiction \| Internal Revenue Service (IRS)
Income Taxes [Line Items]
Net operating loss carryforwards	$ 44,838,000

Components of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Components Of Deferred Tax Assets And Liabilities [Line Items]
Operating loss carryforwards	$ 46,203	$ 39,982
Tax credit carryforwards	910	910
Other temporary differences	5,438	5,278
Deferred Tax Assets, Gross, Total	52,551	46,170
Less valuation allowance	(52,551)	(46,170)
Net deferred tax asset

Primary Factors Affecting Income Tax Rates (Detail)	12 Months Ended
Primary Factors Affecting Income Tax Rates (Detail)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Statutory Tax Rate [Line Items]
Tax benefit at U.S. statutory rates	(21.00%)	(21.00%)	(21.00%)	(34.00%)
State tax benefit	(4.70%)	(4.70%)
Permanent differences	0.80%	0.80%
Impact of the 2017 Tax Act
Other	(2.20%)	(4.20%)
Expiring state NOL's
Changes in valuation allowance	27.10%	29.10%
Effective Income Tax Rate Reconciliation, Percent	0.00%	0.00%