Galectin Therapeutics (GALT) 10-K 31 Mar 21 2020 FY Annual report Financial data

Cover

Cover - USD ($) $ in Millions	12 Months Ended
	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

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 Balanc_2

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 Statemen

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 Statem_2

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 CapitalSeries A 12% convertible preferred stock	Additional Paid-In CapitalSeries C super dividend redeemable convertible preferred stock dividend	Additional Paid-In CapitalSeries B Convertible Preferred Stock [Member]	Retained Deficit	Retained DeficitSeries A 12% convertible preferred stock	Retained DeficitSeries B-1 12% convertible preferred stock	Retained DeficitSeries B-2 12% convertible preferred stock	Retained DeficitSeries B-3 8% convertible preferred stock	Retained DeficitSeries 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

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 Pr

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 company The Company was founded in July 2000, was incorporated in the State of Nevada in January 2001 under the name “Pro-Pharmaceuticals, 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 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 Accounti

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. Use of Estimates. Fair Value Measurements Cash and Cash Equivalents. Prepaid Expenses and Other Current Assets. Property and Equipment. Security Deposit. Long-Lived Assets. Accrued Expenses Warrants. Research and Development Expenses. Income Taxes. Concentration of Credit Risk. Stock-Based Compensation. Recently Adopted Accounting Standards No. 2019-12, 2019-12”), 2019-12

Property and Equipment

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

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

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 B-2 B-3 B-1, B-2 B-3 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, paid-in 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 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 B-2 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 B-1 B-1”) B-2 B-2 B-2”) On September 22, 2016, the Company entered into a securities purchase agreement (the “B-3 B-3 B-3 “Series B-3”) 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, B-2 B-3 B-1 B-2, B-1 B-2 On December 23, 2016, the Company and 10X Fund LP amended the B-3 B-3 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 B-3 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 B-2 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 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 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 non-compounding ® (GM-CT-01), 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 Series C Post Conversion Dividend Right 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 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 B-1 B-2, Redemption 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

Warrants

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 1,200,000 $ 3.00 February 12, 2009 February 12, 2024 May 13, 2009 Series B-2 600,000 $ 3.00 May 13, 2009 May 13, 2024 June 30, 2009 Series B-2 333,333 $ 3.00 June 30, 2009 June 30, 2024 August 12, 2009 Series B-2 200,000 $ 3.00 August 12, 2009 August 12, 2024 September 30, 2009 Series B-2 216,666 $ 3.00 September 30, 2009 September 30, Issued in Connection With Number Issued Exercise Price Exercisable Date Expiration Date November 4, 2009 Series B-2 106,666 $ 3.00 November 4, 2009 November 4, 2024 December 8, 2009 Series B-2 133,143 $ 3.00 December 8, 2009 December 8, 2024 January 29, 2010 Series B-2 216,667 $ 3.00 January 29, 2010 January 29, 2025 March 8, 2010 Series B-2 223,334 $ 3.00 March 8, 2010 March 8, 2025 April 30, 2010 Series B-2 204,192 $ 3.00 April 30, 2010 April 30, 2025 May 10, 2010 Series B-2 143,166 $ 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-3 698,158 $ 3.00 September 22, 2016 September 22, 2023 September 29, 2016 Series B-3 846,100 $ 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-3 924,780 $ 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 Various dates in 2025 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

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 non-employees. non-plan non-plan 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 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

Line of Credit

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)

Loss Per Share

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- 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

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 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

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 galectin-3 in-process non-controlling non-cash

Income Taxes

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 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 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.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Basis of Consolidation	Basis of Consolidation.
Use of Estimates	Use of Estimates.
Fair Value Measurements	Fair Value Measurements
Cash and Cash Equivalents	Cash and Cash Equivalents.
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets.
Property and Equipment	Property and Equipment.
Security Deposit	Security Deposit.
Long-Lived Assets	Long-Lived Assets.
Accrued Expenses	Accrued Expenses
Warrants	Warrants.
Research and Development Expenses	Research and Development Expenses.
Income Taxes	Income Taxes.
Concentration of Credit Risk	Concentration of Credit Risk.
Stock-Based Compensation	Stock-Based Compensation.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards No. 2019-12, 2019-12”), 2019-12

Property and Equipment (Tables)

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)

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)

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)

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 1,200,000 $ 3.00 February 12, 2009 February 12, 2024 May 13, 2009 Series B-2 600,000 $ 3.00 May 13, 2009 May 13, 2024 June 30, 2009 Series B-2 333,333 $ 3.00 June 30, 2009 June 30, 2024 August 12, 2009 Series B-2 200,000 $ 3.00 August 12, 2009 August 12, 2024 September 30, 2009 Series B-2 216,666 $ 3.00 September 30, 2009 September 30, Issued in Connection With Number Issued Exercise Price Exercisable Date Expiration Date November 4, 2009 Series B-2 106,666 $ 3.00 November 4, 2009 November 4, 2024 December 8, 2009 Series B-2 133,143 $ 3.00 December 8, 2009 December 8, 2024 January 29, 2010 Series B-2 216,667 $ 3.00 January 29, 2010 January 29, 2025 March 8, 2010 Series B-2 223,334 $ 3.00 March 8, 2010 March 8, 2025 April 30, 2010 Series B-2 204,192 $ 3.00 April 30, 2010 April 30, 2025 May 10, 2010 Series B-2 143,166 $ 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-3 698,158 $ 3.00 September 22, 2016 September 22, 2023 September 29, 2016 Series B-3 846,100 $ 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-3 924,780 $ 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 Various dates in 2025 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 (Table

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)

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	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 (

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)

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 _2

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 Accoun_3

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)

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 - Additi

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)

Accrued Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	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]	Operating Lease, Liability

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)

May 23, 2019USD ($)yr$ / shares

Apr. 29, 2019USD ($)$ / sharesshares

Jan. 11, 2019shares

Dec. 23, 2016USD ($)shares

Sep. 22, 2016USD ($)shares

Dec. 30, 2010USD ($)$ / sharesshares

Feb. 12, 2009USD ($)shares

Feb. 04, 2008$ / shares

Jun. 30, 2020USD ($)shares

May 31, 2020

Jan. 31, 2019USD ($)yrshares

Jul. 31, 2011shares

Jan. 31, 2011USD ($)$ / sharesshares

Dec. 31, 2020USD ($)$ / sharesshares

Dec. 31, 2019USD ($)shares

Dec. 31, 2018shares

Dec. 31, 2017shares

Dec. 31, 2014shares

Dec. 31, 2013shares

Dec. 31, 2011USD ($)$ / sharesshares

May 31, 2010shares

May 11, 2020USD ($)

Jan. 01, 2019shares

May 19, 2017USD ($)

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

Stock issuance costs | $

$ 47,000

Preferred stock issuable

3,000,000

Preferred stock value | $

$ 6,000,000

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

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

Issuance of warrants, value | $

$ 8,200,000

Termination notice period

30 days

Price per warrants class | $ / shares

$ 7

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

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

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

Series A 12% convertible preferred stock | Minimum

Class of Stock [Line Items]

Minimum closing price of the common stock to require conversion | $ / shares

$ 18

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

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

Number of common stock issued upon conversion

896,997

2020 At Market Agreement

Class of Stock [Line Items]

Aggregate offering price | $

$ 40,000,000

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)

Return on Investment (Detail)	12 Months Ended
	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 (De

Summary of Warrant Activity (Detail) - Warrant - shares	12 Months Ended
	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 Reg

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
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
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
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
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
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
Expiration Date	Nov. 4, 2024
December 8, 2009 Series B-2 Transaction
Equity [Line Items]
Exercisable Date	December 8, 2009
Number Issued	133,143
Exercise Price	$ 3
Expiration Date	Dec. 8, 2024
January 29, 2010 Series B-2 Transaction
Equity [Line Items]
Number Issued	216,667
Exercise Price	$ 3
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
Exercisable Date	Mar. 8, 2010
Expiration Date	Mar. 8, 2025
April 30, 2010 Series B-2 Transaction
Equity [Line Items]
Number Issued	204,192
Exercise Price	$ 3
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
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
Exercisable Date	Sep. 22, 2016
September 29, 2016 Series B-3 Transaction
Equity [Line Items]
Number Issued	846,100
Exercise Price	$ 3
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
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
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
Exercisable Date	Dec. 28, 2016
February 27, 2017 Private Placement Warrants
Equity [Line Items]
Number Issued	76,776
Exercise Price	$ 5
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
December 19, 2017 Line of Credit Warrants
Equity [Line Items]
Number Issued	500,000
Exercise Price	$ 5
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
Exercisable Date	May 23, 2019
Expiration Date	May 23, 2026

Summary of Information with R_2

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
May 13, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	May 13, 2009
Warrant issued price per share	$ 3
June 30, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Jun. 30, 2009
Warrant issued price per share	$ 3
August 12, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Aug. 12, 2009
Warrant issued price per share	$ 3
September 30, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Sep. 30, 2009
Warrant issued price per share	$ 3
November 4, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Nov. 4, 2009
Warrant issued price per share	$ 3
December 8, 2009 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Dec. 8, 2009
Warrant issued price per share	$ 3
January 29, 2010 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Jan. 29, 2010
Warrant issued price per share	$ 3
March 8, 2010 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Mar. 8, 2010
Warrant issued price per share	$ 3
April 30, 2010 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	Apr. 30, 2010
Warrant issued price per share	$ 3
May 10, 2010 Series B-2 Transaction
Equity [Line Items]
Warrant issuance date	May 10, 2010
Warrant issued price per share	$ 3
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
September 29, 2016 Series B-3 Transaction
Equity [Line Items]
Warrant issuance date	Sep. 29, 2016
Warrant issued price per share	$ 3
December 22, 2016 Private Placement Warrants
Equity [Line Items]
Warrant issuance date	Dec. 22, 2016
Warrant issued price per share	$ 3
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 - Addi

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 Expens

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 Us

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 Activit

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 Informati

Summary of Additional Information Regarding Outstanding and Exercisable Options under Stock Based Compensation Plans (Detail)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
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
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
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
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
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 Inf

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
Expected life	7 years
Expected Volatility	98.00%
Expected dividend	0.00%
Risk free interest rate	2.05%

Computation of Diluted Net Loss

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

Dilutive Shares Which Could Exi

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 -

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_2

Commitments and Contingencies - Maturity of operating lease (Details) $ in Thousands	Dec. 31, 2020USD ($)
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]	Present value of lease liability

Galectin Science LLC - Addition

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 Infor

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

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 Incom

Primary Factors Affecting Income Tax Rates (Detail)	12 Months Ended
	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%