ContraFect (CFRXQ) 10-Q 15 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 10, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Entity Interactive Data Current	Yes
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Trading Symbol	CFRX
Entity Registrant Name	CONTRAFECT Corp
Entity Central Index Key	0001478069
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity Shell Company	false
Entity File Number	001-36577
Entity Tax Identification Number	39-2072586
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	28 Wells Avenue
Entity Address, Address Line Two	3rd Floor
Entity Address, City or Town	Yonkers
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10701
City Area Code	914
Local Phone Number	207-2300
Entity Common Stock, Shares Outstanding		39,332,721
Document Quarterly Report	true
Document Transition Report	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 20,225	$ 15,485
Marketable securities	43,092	27,005
Prepaid expenses and other current assets	10,556	4,165
Total current assets	73,873	46,655
Property and equipment, net	784	910
Operating lease right-of-use assets	2,614	2,811
Other assets	571	740
Total assets	77,842	51,116
Current liabilities:
Accounts payable	2,964	1,806
Accrued liabilities	6,252	3,610
Current portion of lease liabilities	654	644
Total current liabilities	9,870	6,060
Warrant liabilities	12,194	29,404
Long-term portion of lease liabilities	2,700	2,959
Other liabilities	73	73
Total liabilities	24,837	38,496
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.0001 par value, 25,000,000 shares authorized and none outstanding at September 30, 2021 and December 31, 2020
Common stock, $0.0001 par value, 125,000,000 shares authorized, 39,332,721 shares and 27,810,161 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	4	3
Additional paid-in capital	309,197	252,908
Accumulated other comprehensive loss	(43)	(21)
Accumulated deficit	(256,153)	(240,270)
Total stockholders' equity	53,005	12,620
Total liabilities and stockholders' equity	$ 77,842	$ 51,116

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	39,332,721	27,810,161
Common stock, shares outstanding	39,332,721	27,810,161

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating expenses
Research and development	$ 8,664	$ 4,706	$ 24,462	$ 15,354
General and administrative	3,022	2,607	8,722	8,186
Total operating expenses	11,686	7,313	33,184	23,540
Loss from operations	(11,686)	(7,313)	(33,184)	(23,540)
Other income (expense):
Interest income	36	58	91	154
Other income (expense)	0	10	0	(2,165)
Change in fair value of warrant liabilities	6,358	10,689	17,210	3,800
Total other income, net	6,394	10,757	17,301	1,789
Net (loss) income	$ (5,292)	$ 3,444	$ (15,883)	$ (21,751)
Basic net (loss) income per share	$ (0.13)	$ 0.12	$ (0.44)	$ (1.03)
Shares used in computing basic net (loss) income per share	39,332,721	27,809,169	35,914,327	21,069,057
Diluted net loss per share	$ (0.13)	$ (0.19)	$ (0.44)	$ (1.03)
Shares used in computing diluted net (loss) income per share	39,332,721	29,079,107	35,914,327	21,069,057

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Loss [Abstract]
Net (loss) income	$ (5,292)	$ 3,444	$ (15,883)	$ (21,751)
Other comprehensive loss:
Unrealized loss on available-for-sale securities	(1)	(1)	(22)	(8)
Comprehensive (loss) income	$ (5,293)	$ 3,443	$ (15,905)	$ (21,759)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2019	$ 15,545	$ 2	$ 227,658	$ 0	$ (212,115)
Beginning Balance, Shares at Dec. 31, 2019		15,332,042
Stock-based compensation	633		633
Unrealized gain/(loss) on marketable securities	9			9
Net income (loss)	(7,578)				(7,578)
Ending balance at Mar. 31, 2020	8,609	$ 2	228,291	9	(219,693)
Ending balance, Shares at Mar. 31, 2020		15,332,042
Beginning Balance at Dec. 31, 2019	15,545	$ 2	227,658	0	(212,115)
Beginning Balance, Shares at Dec. 31, 2019		15,332,042
Net income (loss)	(21,751)
Ending balance at Sep. 30, 2020	18,397	$ 3	252,268	(8)	(233,866)
Ending balance, Shares at Sep. 30, 2020		27,810,082
Beginning Balance at Dec. 31, 2019	$ 15,545	$ 2	227,658	0	(212,115)
Beginning Balance, Shares at Dec. 31, 2019		15,332,042
Issuance of common stock for exercise of warrants, Shares	5,850
Ending balance at Dec. 31, 2020	$ 12,620	$ 3	252,908	(21)	(240,270)
Ending balance, Shares at Dec. 31, 2020		27,810,161
Beginning Balance at Mar. 31, 2020	8,609	$ 2	228,291	9	(219,693)
Beginning Balance, Shares at Mar. 31, 2020		15,332,042
Issuance of securities in registered offering	21,108	$ 1	21,107
Issuance of securities in registered offering, Shares		11,797,752
Issuance of securities in private placement	3,000		3,000
Issuance of securities in private placement, Shares		674,156
Financing cost of sale of securities	(1,462)		(1,462)
Issuance of common stock for exercise of options, Shares		282
Stock-based compensation	652		652
Unrealized gain/(loss) on marketable securities	(16)			(16)
Net income (loss)	(17,617)				(17,617)
Ending balance at Jun. 30, 2020	14,274	$ 3	251,588	(7)	(237,310)
Ending balance, Shares at Jun. 30, 2020		27,804,232
Issuance of common stock for exercise of warrants	28		28
Issuance of common stock for exercise of warrants, Shares		5,850
Stock-based compensation	652		652
Unrealized gain/(loss) on marketable securities	(1)			(1)
Net income (loss)	3,444				3,444
Ending balance at Sep. 30, 2020	18,397	$ 3	252,268	(8)	(233,866)
Ending balance, Shares at Sep. 30, 2020		27,810,082
Beginning Balance at Dec. 31, 2020	12,620	$ 3	252,908	(21)	(240,270)
Beginning Balance, Shares at Dec. 31, 2020		27,810,161
Issuance of securities in registered offering	57,500	$ 1	57,499
Issuance of securities in registered offering, Shares		11,500,000
Financing cost of sale of securities	(3,703)		(3,703)
Issuance of common stock for exercise of warrants	110		110
Issuance of common stock for exercise of warrants, Shares		22,560
Stock-based compensation	581		581
Unrealized gain/(loss) on marketable securities	(8)			(8)
Net income (loss)	(5,195)				(5,195)
Ending balance at Mar. 31, 2021	61,905	$ 4	307,395	(29)	(245,465)
Ending balance, Shares at Mar. 31, 2021		39,332,721
Beginning Balance at Dec. 31, 2020	$ 12,620	$ 3	252,908	(21)	(240,270)
Beginning Balance, Shares at Dec. 31, 2020		27,810,161
Issuance of common stock for exercise of warrants, Shares	22,560
Issuance of common stock for exercise of options, Shares	0
Net income (loss)	$ (15,883)
Ending balance at Sep. 30, 2021	53,005	$ 4	309,197	(43)	(256,153)
Ending balance, Shares at Sep. 30, 2021		39,332,721
Beginning Balance at Mar. 31, 2021	61,905	$ 4	307,395	(29)	(245,465)
Beginning Balance, Shares at Mar. 31, 2021		39,332,721
Stock-based compensation	938		938
Unrealized gain/(loss) on marketable securities	(13)			(13)
Net income (loss)	(5,396)				(5,396)
Ending balance at Jun. 30, 2021	57,434	$ 4	308,333	(42)	(250,861)
Ending balance, Shares at Jun. 30, 2021		39,332,721
Stock-based compensation	864		864
Unrealized gain/(loss) on marketable securities	(1)			(1)
Net income (loss)	(5,292)				(5,292)
Ending balance at Sep. 30, 2021	$ 53,005	$ 4	$ 309,197	$ (43)	$ (256,153)
Ending balance, Shares at Sep. 30, 2021		39,332,721

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net loss	$ (15,883)	$ (21,751)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	110	126
Stock-based compensation expense	2,383	1,937
Change in fair value of warrant liabilities	(17,210)	(3,800)
Issuance costs allocated to warrants		2,175
Net amortization of premium on marketable securities	503	161
Changes in operating assets and liabilities:
(Increase) decrease in prepaid expenses and other current and non-current assets	(6,260)	720
Increase (decrease) in accounts payable, accrued liabilities and other liabilities	3,800	(5,240)
Net cash used in operating activities	(32,557)	(25,672)
Cash flows from investing activities
Purchases of marketable securities	(47,644)	(47,555)
Proceeds from sales and maturities of marketable securities	31,034	15,303
Net cash used in investing activities	(16,610)	(32,252)
Cash flows from financing activities
Proceeds from issuance of securities	57,500	55,500
Payment of financing costs of securities sold	(3,703)	(3,637)
Proceeds from the exercise of warrants	110	29
Net cash provided by financing activities	53,907	51,892
Net increase (decrease) in cash and cash equivalents	4,740	(6,032)
Cash and cash equivalents at beginning of period	15,485	24,184
Cash and cash equivalents at end of period	$ 20,225	18,152
Supplemental disclosures of cash flow information:
Issuance of warrants to purchase common stock		$ 31,392

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Organization and Description of Business	1. Organization and Description of Business Organization and Business ContraFect Corporation (the “Company”) is a clinical-stage biotechnology company focused on the discovery and development of direct lytic agents (“DLAs”), including lysins and amurin peptides, as new medical modalities for the treatment of life-threatening, antibiotic-resistant infections. The Company intends to address antibiotic-resistant infections using product candidates from our lysin and amurin peptide platforms. DLAs are fundamentally different than antibiotics and offer a potential paradigm shift in the treatment of antibiotic-resistant infections. The Company’s most advanced product candidate is exebacase, a lysin which targets Staph aureus Staph aureus Staph aureus Staph aureus 30-day all-cause The Company has incurred losses from operations since inception as a research and development organization and has an accumulated deficit of $256.2 million as of September 30, 2021. For the nine months ended September 30, 2021, the Company used $32.6 million of cash in operations. The Company has relied on its ability to fund its operations through public and private debt and equity financings, and, to a lesser extent, grant funding. Management believes that its existing cash, cash equivalents and marketable securities, will be sufficient to fund operations for at least 12 months from the issuance date of these financial statements. The Company expects operating losses and negative cash flows to continue at significant levels in the future as it continues its clinical trials. Transition to profitability is dependent upon the successful development, approval, and commercialization of its product candidates and achieving a level of revenues adequate to support the Company’s cost structure. The Company may never achieve profitability, and unless and until it does, the Company will continue to need to raise additional capital. Management intends to fund future operations through additional public or private debt and equity financings, and may seek additional capital through arrangements with strategic partners or from other sources. There can be no assurances that such financing will be available to the Company on satisfactory terms, or at all. On August 14, 2020, the Company filed a new shelf registration statement on Form S-3 S-3”) S-3 S-3 time-to-time On March 22, 2021, the Company completed an underwritten public offering under the Form S-3

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial information as of September 30, 2021 and for the three and nine months ended September 30, 2021 and 2020 has been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) have been condensed or omitted pursuant to such rules and regulations. The consolidated balance sheet as of December 31, 2020 was derived from the Company’s audited consolidated financial statements. The Company’s audited consolidated financial statements as of and for the year ended December 31, 2020, including all related disclosures and the complete listing of significant accounting policies as described in Note 2 thereof, are included in the Company’s Annual Report on Form 10-K In the opinion of management, the unaudited financial information as of September 30, 2021 and for the three and nine months ended September 30, 2021 and 2020 reflects all adjustments, which are normal recurring adjustments, necessary to present a fair statement of financial position, results of operations and cash flows. The results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the operating results for the full fiscal year or any future periods. Principles of Consolidation The Company has a wholly-owned subsidiary, ContraFect International Limited, in Scotland that established legal status for previous interactions with the European Economic Area. This subsidiary is dormant or is otherwise non-operative. Significant Risks and Uncertainties The Company’s operations are subject to a number of factors that can affect its operating results and financial condition. Such factors include, but are not limited to, the results of clinical testing and trial activities of the Company’s products, the Company’s ability to obtain regulatory approval to market its products, competition from products manufactured and sold or being developed by other companies, the price of, and demand for, the Company’s products, the Company’s ability to negotiate favorable licensing or other manufacturing and marketing agreements for its products, the Company’s ability to raise capital and the effects of the novel coronavirus, or COVID-19, The ongoing COVID-19 COVID-19 COVID-19 The pandemic has had an impact, both directly and indirectly, on the Company. The full extent of the impact on the Company’s business, results of operations, financial condition and liquidity, including expenses, research and development, manufacturing costs and timelines, and clinical trial progress, will depend on future developments that remain highly uncertain. Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. The Company bases estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. On an ongoing basis, the Company evaluates its estimates and assumptions, including those related to accruals, stock-based compensation, valuation of warrant liabilities and income taxes. The Company’s actual results may differ from these estimates under different assumptions or conditions, including the effects of significant risks and uncertainties. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company holds these investments in highly rated financial institutions, and, by policy, limits the amounts of credit exposure to any one financial institution. These amounts at times may exceed federally insured limits. The Company has not experienced any credit losses in such accounts and does not believe it is exposed to any significant credit risk on these funds. The Company has no off-balance Cash and Cash Equivalents The Company considers all highly liquid investments with maturities at the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents include bank demand deposits, marketable securities with maturities of three months or less at purchase, and money market funds that invest primarily in certificates of deposit, commercial paper and U.S. government and U.S. government agency obligations. Cash equivalents are reported at fair value. Marketable Securities Marketable securities consist of investments in corporate debt securities. Management determines the appropriate classification of the securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company classifies its marketable securities as available-for-sale Marketable securities are recorded at fair value, with unrealized gains and losses included as a component of accumulated other comprehensive (loss) income in stockholders’ equity and a component of total comprehensive (loss) (loss) , The Company reviews marketable securities for other-than-temporary impairment whenever the fair value of a marketable security is less than the amortized cost and evidence indicates that a marketable security’s carrying amount is not recoverable within a reasonable period of time. Other-than- temporary impairments of investments are recognized in the consolidated statements of operations if the Company has experienced a credit loss, has the intent to sell the marketable security, or if it is more likely than not that the Company will be required to sell the marketable security before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period . Fair Value of Financial Instruments The Company’s financial instruments consist of cash and cash equivalents, marketable securities, accounts payable, accrued liabilities and warrant liabilities. Fair value estimates of these instruments are made at a specific point in time, based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. The fair value of the Company’s warrant liabilities are based upon unobservable inputs, as described further below. The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. Financial Accounting Standards Board (“FASB”) Accounting Standard Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures The three levels of the fair value hierarchy are described below: Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reported in the accompanying financial statements for accounts payable and accrued liabilities approximate their respective fair values due to their short-term maturities. The fair value of the warrant liabilities is discussed in Note 4, “Fair Value Measurements.” Stock-based Compensation The Company accounts for stock-based compensation in accordance with ASC 718, Compensation—Stock Compensation, which requires the measurement and recognition of compensation expense for all stock-based payment awards made to employees, non-employees non-employee The fair value of options is calculated using the Black-Scholes option pricing model to determine the fair value of stock options on the date of grant based on key assumptions such as stock price, expected volatility and expected term. The Company’s estimates of these assumptions are primarily based on historical data and judgment regarding future trends and factors. Government Contracts and Grant Agreements On March 10, 2021, the Company entered into a cost-share contract (the “BARDA Contract”) with BARDA, a division of the U.S. Department of Health and Human Services’ Office of the Assistant Secretary for Preparedness and Response. The Company evaluated the BARDA Contract under Topic 606 and determined that it does not fall within the scope of Topic 606. Accordingly, the Company considered other relevant guidance and concluded that the BARDA Contract will be accounted for consistent with its accounting practices related to its existing grant agreements. The Company recognizes a receivable and the related reduction in its research and development expenses when the actual reimbursable costs have been incurred and there is reasonable assurance that the Company has complied with the conditions of the applicable government contract or grant agreement and the amounts will be received. The Company recognized a reduction to its research and development expense in the amount of approximately $3.7 million and $1.0 million for the three months ended September 30, 2021 and 2020 respectively, and $7.7 million and $3.4 million for the nine months ended September 30, 2021 and 2020, respectively. The receivable for government contracts and grant agreements as of September 30, 2021 and December 31, 2020 was approximately $4.4 million and $1.1 million, respectively, and is included in prepaid expenses and other current assets on the balance sheet. The Company has approximately $10.5 million of committed government contract and grant agreement funding remaining as of September 30, 2021. Leases The Company accounts for leases in accordance with Accounting Standards Update No. 2016-02- Leases right-of-use Note 8 Under the Company’s policy, it does not record an ROU asset or corresponding liability for arrangements where the initial lease term is one year or less. Those leases are expensed on a straight-line basis over the term of the lease. Net (Loss) Income Per Share Basic net (loss) income per share is calculated by dividing net (loss) income by the weighted average shares outstanding during the period, without consideration for common stock equivalents. Diluted net (loss) income per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method. For purposes of a dilutive net loss per share calculation, stock options and warrants are considered to be common stock equivalents but are excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive given the Company’s net loss. Common stock equivalents may also be excluded from the calculation of diluted net (loss) Recently Adopted Accounting Pronouncements Income Taxes On January 1, 2021, the Company adopted Accounting Standards Update No. 2019-12- Income Taxes (Topic 740) Recently Issued Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued a new Accounting Standards Update, Financial Instruments-Credit Losses (ASU 2016-13). 2016-13 available-for-sale

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	3. Marketable Securities Marketable securities at September 30, 2021 consisted of the following (in thousands): Marketable Securities Amortized Cost Unrealized Unrealized Fair Current: Corporate Debt $ 43,134 $ 1 $ (43 ) $ 43,092 Marketable securities at December 31, 2020 consisted of the following (in thousands): Marketable Securities Amortized Cost Unrealized Unrealized Fair Current: Corporate debt $ 27,026 $ 6 $ (27) $ 27,005 Corporate debt includes obligations issued by investment-grade corporations, and may include issues that have been guaranteed by governments and government agencies. Investments classified as short-term have maturities of less than one year, and investments classified as long-term are those that have maturities of greater than one year and management does not intend to liquidate within the next twelve months. All of the Company’s marketable securities have an effective maturity of less than two years. At September 30, 2021, the Company held 23 debt securities that individually and in total were in an immaterial unrealized loss position for less than one year. The aggregate fair value of debt securities in an unrealized loss position at September 30, 2021 was approximately $38.3 million. The Company evaluated its securities for other than temporary impairment and considered the decline in market value for the securities to be primarily attributable to current economic and market conditions. It was not more likely than not that the Company would have been required to sell the securities prior to the recovery of the amortized cost basis. Based on this analysis, these marketable securities were not considered to be other-than-temporarily impaired as of September 30, 2021.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The following fair value hierarchy table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2021 and December 31, 2020 (in thousands): Fair Value Measurement as of September 30, 2021 Quoted Prices Significant Significant Cash equivalents $ 14,116 $ — $ — Marketable securities 43,092 — — Warrant liabilities — — 12,194 Total $ 57,208 $ — $ 12,194 Fair Value Measurement as of December 31, 2020 Quoted Prices Significant Significant Cash equivalents $ 12,921 $ — $ — Marketable securities 27,005 Warrant liabilities — — 29,404 Total $ 39,926 $ — $ 29,404 The Company issued warrants to the purchasers of its July 27, 2016 offering (the “2016 Warrants”). The Company determined that these warrants should be classified as a liability and considered as a Level 3 financial instrument (see also Note 9 re-measured As of Expected volatility 59.7 % Remaining contractual term (in years) 0.58 Risk-free interest rate 0.09 % Expected dividend yield — % The Company issued warrants to the purchasers of its July 25, 2017 offering (the “2017 Warrants”). The Company determined that these warrants should be classified as a liability and considered as a Level 3 financial instrument (see also Note 9 re-measured As of As of Expected volatility 64.1 % 100.1 % Remaining contractual term (in years) 0.83 1.58 Risk-free interest rate 0.09 % 0.12 % Expected dividend yield — % — % The Company issued warrants to the purchasers of its May 27, 2020 registered offering of securities (the “2020 Warrants”). The Company determined that these warrants should be classified as a liability and considered as a Level 3 financial instrument (see also Note 9 re-measured As of As of Expected volatility 80.3 % 111.9 % Remaining contractual term (in years) 1.67 2.42 Risk-free interest rate 0.28 % 0.15 % Expected dividend yield — % — % The following tables present a reconciliation of the Company’s financial liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three and nine months ended September 30, 2021 and 2020 (in thousands): Warrant liabilities Three Months Ended Nine Months Ended 2021 2020 2021 2020 Balance at beginning of period $ 18,552 $ 44,350 $ 29,404 $ 6,069 Issuance of 2020 Warrants — — — 31,392 Decrease in fair value (1) (6,358 ) (10,689 ) (17,210 ) (3,800 ) Balance at end of perio d $ 12,194 $ 33,661 $ 12,194 $ 33,661 (1) The change in fair values of the warrant liabilities is recorded in other income (expense) in the consolidated statement of operations. The key inputs into the Black-Scholes option pricing model are the current per-share

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2021
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid Expenses and Other Current Assets	5. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): September 30, December 31, Prepaid research and development costs $ 4,882 $ 2,358 Government contract and grant agreement receivables 4,419 1,081 Prepaid insurance premiums 1,098 649 Other prepaid expenses 157 77 Total prepaid expenses and other current assets $ 10,556 $ 4,165

Accrued Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Accrued Liabilities	6. Accrued Liabilities Accrued liabilities consist of the following (in thousands): September 30, December 31, Accrued research and development service fees $ 3,695 $ 801 Accrued compensation costs 1,798 2,069 Accrued professional fees 618 456 Accrued facilities operation expenses 122 173 Other accrued liabilities 19 111 Total accrued liabilities $ 6,252 $ 3,610

Net Loss (Income) Per Share of

Net Loss (Income) Per Share of Common Stock	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share of Common Stock	7 (Income) Basic net (loss) income per share is computed by dividing net (loss) income by the weighted-average number of shares of common stock outstanding. For the three months ended September 30, 2021 and the nine months ended September 30, 2021 and 2020, the Company incurred a net loss and therefore diluted net loss per share is the same as basic net loss per share as the Company excluded certain potentially dilutive securities from the computation of diluted weighted average shares outstanding as they would have been anti-dilutive. For the three months ended September 30, 2020, the impact of the outstanding 2020 Warrants was determined to be dilutive. As a result, the Company adjusted the numerator amount used in the calculation of net (loss) income per diluted share to remove the gain associated with the change in fair value of $8,826,913. Additionally, the 1,269,938 net shares required under the treasury stock method upon exercise of the 2020 Warrants were included in the denominator in the calculation of dilutednet loss per share. The following table sets forth the computation of basic and diluted net income (loss) per share for common stockholders (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Net (loss) $ (5,292 ) $ 3,444 $ (15,883 ) $ (21,751 ) Less: decrease in fair value of 2020 Warrants, net of tax — (8,827 ) — — Net loss – diluted $ (5,292 ) $ (5,383 ) $ (15,883 ) $ (21,751 ) Shares used in computing basic net (loss) income per share 39,332,721 27,809,169 35,914,327 21,069,057 Plus: dilutive effect of 2020 Warrants — 1,270 — — Shares used in computing diluted net loss per share 39,332,721 29,079,107 35,914,327 21,069,057 Basic net (loss) $ (0.13 ) $ 0.12 $ (0.44 ) $ (1.03 ) Diluted net loss per share $ (0.13 ) $ (0.19 ) $ (0.44 ) $ (1.03 ) The following table sets forth the potentially dilutive securities outstanding as of September 30, 2021 and 2020 that were excluded from the computation of diluted weighted average shares outstanding, as they would have been anti-dilutive: September 30, 2021 2020 Options to purchase common stock 2,950,551 1,864,631 Warrants to purchase common stock 10,926,733 12,354,580 Total 13,877,284 14,219,211

Commitments

Commitments	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments	8 Leases In December 2010, the Company entered into a non-cancellable In January 2012, the Company entered into a non-cancellable The Company performed an evaluation of its other contracts in accordance with Topic 842 and has determined that, except for the leases described above, none of its contracts contain a lease. The balance sheet classification of the Company’s lease liabilities was as follows (in thousands): Description September 30, December 31, Operating lease liabilities: Current portion of lease liabilities $ 654 $ 644 Long-term portion of lease liabilities $ 2,700 $ 2,959 Operating lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. The leases are renewable at the end of the lease term at our option. For the purposes of determining the remaining lease term in contemplation of available extensions, the Company did not consider either renewal to be probable at this time. In determining the present value of lease payments, the Company estimated its incremental borrowing rate, or discount rate, based on the information available at the adoption date of Topic 842. The discount rate used to determine the operating lease liability was 9.93%. As of September 30, 2021, the maturities of our operating lease liabilities were as follow s Amount October 1, 2021 - December 31, 2021 $ 171 Year ending December 31: 2022 693 2023 707 2024 721 2025 736 Thereafter 1,452 Total lease payments 4,480 Less: Present value adjustment (1,126 ) Operating lease liabilities 3,354 Lease costs under the terms of the Company’s leases for the three and nine months ended September 30, 2021 and 2020 were as follows (in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Operating lease cost (1) $ 154 $ 154 $ 461 $ 461 Variable lease costs (2) 46 43 111 89 Total lease cost $ 200 $ 197 $ 572 $ 550 (1) Operating lease payments included in the measurement of the Company’s lease liabilities are comprised of fixed payments according to the terms of the Company’s leases. (2) Variable lease payments consist of the Company’s utility costs billed by and paid to its landlord. Variable lease payments are presented as operating expenses in the Company’s Consolidated Statement of Operations in the same line item as expense arising from fixed lease payments and in net cash used in operating activities in the Company’s Statement of Cash Flows.

Capital Structure

Capital Structure	9 Months Ended
	Sep. 30, 2021
Federal Home Loan Banks [Abstract]
Capital Structure	9 As of September 30, 2021, the Company was authorized to issue 125,000,000 shares of common stock. Follow-on On March 22, 2021, the Company completed an underwritten public offering of 11,500,000 shares of its common stock, including shares sold pursuant to the fully exercised overallotment option granted to the underwriters in connection with the offering, at a public offering price of $5.00 per share, resulting in net proceeds to the Company of approximately $53.8 million after underwriting discounts and commissions and offering expenses payable by the Company. On May 27, 2020, the Company completed an underwritten public offering of 11,797,752 shares of its common stock and warrants to purchase an additional 8,848,314 shares of its common stock at an exercise price of $4.90 per share. The public offering price was $4.45 for one share of common stock and an accompanying warrant to purchase 0.75 shares of common stock, resulting in net proceeds to the Company of approximately $48.9 million after underwriting discounts and commissions and offering expenses payable by the Company. The Company completed a concurrent private placement to Pfizer Inc. (“Pfizer”) of 674,156 shares of common stock and an accompanying warrant to purchase an additional 505,617 shares of its common stock at an exercise price of $4.90 per share (the “Pfizer Warrant”) at a price of $4.45 for one share of common stock and an accompanying warrant to purchase 0.75 shares of common stock, resulting in net proceeds to the Company of approximately $3.0 million. Warrants to purchase 22,560 shares of common stock were exercised during the nine months ended September 30, 2021 and warrants to purchase 5,850 shares of common stock were exercised during the year ended December 31, 2020. The Company issued warrants in its 2020, 2017 and 2016 offerings. These warrants contain a fundamental transaction provision that obligates the Company to cash settle the warrants under a limited set of conditions not entirely within the Company’s control. Due to this conditional obligation, the Company determined that the 2020 Warrants, the 2017 Warrants and the 2016 Warrants should be classified as liabilities in the Company’s consolidated balance sheet. At issuance, the Company determined the fair value of the 2020 Warrants, the 2017 Warrants and 2016 Warrants to be $31.4 million, $12.4 million and $18.6 million, respectively, and reclassified these balances from stockholders’ equity to warrant liability. The fair value of these warrants is re-measured The Pfizer Warrant does not contain the same fundamental transaction provision that obligates the Company to cash settle the warrants under a limited set of conditions not entirely within the Company’s control. Therefore, the Company determined that the Pfizer Warrant should be classified as equity in the Company’s consolidated balance sheet. Voting The holders of shares of common stock are entitled to one vote for each share of common stock held at all meetings of stockholders and written actions in lieu of meetings. Dividends The holders of shares of common stock are entitled to receive dividends, if and when declared by the board of directors. As of September 30, 2021, no dividends have been declared or paid on the Company’s common stock since inception. Reserved for Future Issuance The Company has reserved for future issuance the following number of shares of common stock as of September 30, 2021 and December 31, 2020: September 30, December 31, Outstanding options to purchase common stock 2,950,551 1,853,841 Outstanding warrants to purchase common stock 10,926,733 12,350,293 For future issuance under the 2014 Plan 26,774 41,079 13,904,058 14,245,213

Stock Warrants

Stock Warrants	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Stock Warrants	10 As of September 30, 2021 and December 31, 2020, the Company had warrants to purchase the underlying common stock outstanding as shown in the table below. September 30, December 31, 2020 Warrants 8,819,904 8,842,464 2017 Warrants 1,599,645 1,599,645 2016 Warrants — 1,400,000 Pfizer Warrant 505,617 505,617 Other warrants (1) 1,567 2,567 Warrants to purchase common stock 10,926,733 12,350,293 Weighted-average exercise price per share $ 6.47 $ 9.14 (1) Other warrants are comprised of warrants issued prior to the Company’s initial public offering (“IPO”), generally in exchange for services rendered to the Company. The following table summarizes information regarding the Company’s warrants outstanding at September 30, 2021: Exercise Prices Shares Expiration Date £ 9,325,521 May 27, 2023 > $10.00 £ 1,599,645 July 25, 2022 > $20.00 1,567 October 17, 2021 – January 5, 2022 10,926,733

Stock Option and Incentive Plan

Stock Option and Incentive Plans	9 Months Ended
	Sep. 30, 2021
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option and Incentive Plans	1 1 Amended and Restated 2008 Equity Incentive Plan In July 2008, the Company adopted the 2008 Equity Incentive Plan (the “Plan”). On February 26, 2013, the board of directors approved an amended and restated plan (the “Amended Plan”) under which the number of shares of common stock available for issuance was 157,143. For new awards, the period that vested awards would remain exercisable upon termination of service was reduced from ten years to two years. The board of directors also increased the number of shares of common stock available under the Company’s Amended Plan on February 24, 2014 and April 29, 2014 to 185,714 and 235,714, respectively. As of the closing of the Company’s IPO, there were no further grants made under the Amended Plan. 2014 Omnibus Incentive Plan In April 2014, the Company’s board of directors adopted the 2014 Omnibus Incentive Plan (the “2014 Plan”). The 2014 Plan was approved by the Company’s stockholders on July 3, 2014. The 2014 Plan allows for the granting of incentive and non-qualified The Company recognized compensation expense for stock Number of Weighted Weighted Aggregate Options outstanding at December 31, 2020 1,853,841 $ 14.33 Granted 1,227,500 4.31 Exercised — — Expired (95,978 ) 46.18 Forfeited (34,812 ) 5.62 Options outstanding at September 30, 2021 2,950,551 9.22 8.10 $ 72,725 Vested and exercisable at September 30, 2021 1,324,857 13.74 6.86 $ 16,125 The fair value of each option grant is estimated on the date of the grant using the Black-Scholes option-pricing model. The weighted average grant date fair value of options granted during the three months ended September 30, 2021 and 2020 was $3.93 and $5.66, respectively, and during the nine months ended September 30, 2021 and 2020 was $4.31 and $9.77, respectively. Total compensation expense recognized amounted to $0.9 million and $0.7 million for the three months ended September 30, 2021 and 2020, respectively, and $2.4 million and $1.9 million for the nine months ended September 30, 2021 and 2020, respectively. As of September 30, 2021, the total remaining unrecognized compensation cost related to unvested stock options was approximately $6.7 million which will be recognized over a weighted average period of approximately 2.58 years. The following assumptions were used to compute the fair value of stock options granted during the period: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Risk free interest rate 0.81 % 0.27 % 0.83 % 1.15 % Expected dividend yield — — — — Expected term (in years) 6.12 6.12 5.99 6.03 Expected volatility 95.1 % 97.4 % 94.5 % 94.6 % Risk-free interest rate Expected dividend yield— Expected term—

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial information as of September 30, 2021 and for the three and nine months ended September 30, 2021 and 2020 has been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) have been condensed or omitted pursuant to such rules and regulations. The consolidated balance sheet as of December 31, 2020 was derived from the Company’s audited consolidated financial statements. The Company’s audited consolidated financial statements as of and for the year ended December 31, 2020, including all related disclosures and the complete listing of significant accounting policies as described in Note 2 thereof, are included in the Company’s Annual Report on Form 10-K In the opinion of management, the unaudited financial information as of September 30, 2021 and for the three and nine months ended September 30, 2021 and 2020 reflects all adjustments, which are normal recurring adjustments, necessary to present a fair statement of financial position, results of operations and cash flows. The results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the operating results for the full fiscal year or any future periods.
Principles of Consolidation	Principles of Consolidation The Company has a wholly-owned subsidiary, ContraFect International Limited, in Scotland that established legal status for previous interactions with the European Economic Area. This subsidiary is dormant or is otherwise non-operative.
Significant Risks and Uncertainties	Significant Risks and Uncertainties The Company’s operations are subject to a number of factors that can affect its operating results and financial condition. Such factors include, but are not limited to, the results of clinical testing and trial activities of the Company’s products, the Company’s ability to obtain regulatory approval to market its products, competition from products manufactured and sold or being developed by other companies, the price of, and demand for, the Company’s products, the Company’s ability to negotiate favorable licensing or other manufacturing and marketing agreements for its products, the Company’s ability to raise capital and the effects of the novel coronavirus, or COVID-19, The ongoing COVID-19 COVID-19 COVID-19 The pandemic has had an impact, both directly and indirectly, on the Company. The full extent of the impact on the Company’s business, results of operations, financial condition and liquidity, including expenses, research and development, manufacturing costs and timelines, and clinical trial progress, will depend on future developments that remain highly uncertain.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. The Company bases estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. On an ongoing basis, the Company evaluates its estimates and assumptions, including those related to accruals, stock-based compensation, valuation of warrant liabilities and income taxes. The Company’s actual results may differ from these estimates under different assumptions or conditions, including the effects of significant risks and uncertainties.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company holds these investments in highly rated financial institutions, and, by policy, limits the amounts of credit exposure to any one financial institution. These amounts at times may exceed federally insured limits. The Company has not experienced any credit losses in such accounts and does not believe it is exposed to any significant credit risk on these funds. The Company has no off-balance
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities at the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents include bank demand deposits, marketable securities with maturities of three months or less at purchase, and money market funds that invest primarily in certificates of deposit, commercial paper and U.S. government and U.S. government agency obligations. Cash equivalents are reported at fair value.
Marketable Securities	Marketable Securities Marketable securities consist of investments in corporate debt securities. Management determines the appropriate classification of the securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company classifies its marketable securities as available-for-sale Marketable securities are recorded at fair value, with unrealized gains and losses included as a component of accumulated other comprehensive (loss) income in stockholders’ equity and a component of total comprehensive (loss) (loss) , The Company reviews marketable securities for other-than-temporary impairment whenever the fair value of a marketable security is less than the amortized cost and evidence indicates that a marketable security’s carrying amount is not recoverable within a reasonable period of time. Other-than- temporary impairments of investments are recognized in the consolidated statements of operations if the Company has experienced a credit loss, has the intent to sell the marketable security, or if it is more likely than not that the Company will be required to sell the marketable security before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period .
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial instruments consist of cash and cash equivalents, marketable securities, accounts payable, accrued liabilities and warrant liabilities. Fair value estimates of these instruments are made at a specific point in time, based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. The fair value of the Company’s warrant liabilities are based upon unobservable inputs, as described further below. The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. Financial Accounting Standards Board (“FASB”) Accounting Standard Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures The three levels of the fair value hierarchy are described below: Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reported in the accompanying financial statements for accounts payable and accrued liabilities approximate their respective fair values due to their short-term maturities. The fair value of the warrant liabilities is discussed in Note 4, “Fair Value Measurements.”
Stock-based Compensation	Stock-based Compensation The Company accounts for stock-based compensation in accordance with ASC 718, Compensation—Stock Compensation, which requires the measurement and recognition of compensation expense for all stock-based payment awards made to employees, non-employees non-employee The fair value of options is calculated using the Black-Scholes option pricing model to determine the fair value of stock options on the date of grant based on key assumptions such as stock price, expected volatility and expected term. The Company’s estimates of these assumptions are primarily based on historical data and judgment regarding future trends and factors.
Government Contracts and Grant Agreements	Government Contracts and Grant Agreements On March 10, 2021, the Company entered into a cost-share contract (the “BARDA Contract”) with BARDA, a division of the U.S. Department of Health and Human Services’ Office of the Assistant Secretary for Preparedness and Response. The Company evaluated the BARDA Contract under Topic 606 and determined that it does not fall within the scope of Topic 606. Accordingly, the Company considered other relevant guidance and concluded that the BARDA Contract will be accounted for consistent with its accounting practices related to its existing grant agreements. The Company recognizes a receivable and the related reduction in its research and development expenses when the actual reimbursable costs have been incurred and there is reasonable assurance that the Company has complied with the conditions of the applicable government contract or grant agreement and the amounts will be received. The Company recognized a reduction to its research and development expense in the amount of approximately $3.7 million and $1.0 million for the three months ended September 30, 2021 and 2020 respectively, and $7.7 million and $3.4 million for the nine months ended September 30, 2021 and 2020, respectively. The receivable for government contracts and grant agreements as of September 30, 2021 and December 31, 2020 was approximately $4.4 million and $1.1 million, respectively, and is included in prepaid expenses and other current assets on the balance sheet. The Company has approximately $10.5 million of committed government contract and grant agreement funding remaining as of September 30, 2021.
Leases	Leases The Company accounts for leases in accordance with Accounting Standards Update No. 2016-02- Leases right-of-use Note 8 Under the Company’s policy, it does not record an ROU asset or corresponding liability for arrangements where the initial lease term is one year or less. Those leases are expensed on a straight-line basis over the term of the lease.
Net (Loss) Income Per Share	Net (Loss) Income Per Share Basic net (loss) income per share is calculated by dividing net (loss) income by the weighted average shares outstanding during the period, without consideration for common stock equivalents. Diluted net (loss) income per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method. For purposes of a dilutive net loss per share calculation, stock options and warrants are considered to be common stock equivalents but are excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive given the Company’s net loss. Common stock equivalents may also be excluded from the calculation of diluted net (loss)
Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements Income Taxes On January 1, 2021, the Company adopted Accounting Standards Update No. 2019-12- Income Taxes (Topic 740) Recently Issued Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued a new Accounting Standards Update, Financial Instruments-Credit Losses (ASU 2016-13). 2016-13 available-for-sale

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of Marketable Securities	Marketable securities at September 30, 2021 consisted of the following (in thousands): Marketable Securities Amortized Cost Unrealized Unrealized Fair Current: Corporate Debt $ 43,134 $ 1 $ (43 ) $ 43,092 Marketable securities at December 31, 2020 consisted of the following (in thousands): Marketable Securities Amortized Cost Unrealized Unrealized Fair Current: Corporate debt $ 27,026 $ 6 $ (27) $ 27,005

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Information about Company's Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following fair value hierarchy table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2021 and December 31, 2020 (in thousands): Fair Value Measurement as of September 30, 2021 Quoted Prices Significant Significant Cash equivalents $ 14,116 $ — $ — Marketable securities 43,092 — — Warrant liabilities — — 12,194 Total $ 57,208 $ — $ 12,194 Fair Value Measurement as of December 31, 2020 Quoted Prices Significant Significant Cash equivalents $ 12,921 $ — $ — Marketable securities 27,005 Warrant liabilities — — 29,404 Total $ 39,926 $ — $ 29,404
Reconciliation of Company's Financial Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)	The following tables present a reconciliation of the Company’s financial liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three and nine months ended September 30, 2021 and 2020 (in thousands): Warrant liabilities Three Months Ended Nine Months Ended 2021 2020 2021 2020 Balance at beginning of period $ 18,552 $ 44,350 $ 29,404 $ 6,069 Issuance of 2020 Warrants — — — 31,392 Decrease in fair value (1) (6,358 ) (10,689 ) (17,210 ) (3,800 ) Balance at end of perio d $ 12,194 $ 33,661 $ 12,194 $ 33,661 (1) The change in fair values of the warrant liabilities is recorded in other income (expense) in the consolidated statement of operations.
2016 Warrants [Member]
Assumption Used to Determine Fair Value of Warrant Liability	The following assumptions were used in a Black-Scholes option-pricing model to determine the fair value of the warrant liability: As of Expected volatility 59.7 % Remaining contractual term (in years) 0.58 Risk-free interest rate 0.09 % Expected dividend yield — %
2017 Warrants [Member]
Assumption Used to Determine Fair Value of Warrant Liability	The following assumptions were used in a Black-Scholes option-pricing model to determine the fair value of the warrant liability: As of As of Expected volatility 64.1 % 100.1 % Remaining contractual term (in years) 0.83 1.58 Risk-free interest rate 0.09 % 0.12 % Expected dividend yield — % — %
2020 Warrants [Member]
Assumption Used to Determine Fair Value of Warrant Liability	The following assumptions were used in a Black-Scholes option-pricing model to determine the fair value of the warrant liability: As of As of Expected volatility 80.3 % 111.9 % Remaining contractual term (in years) 1.67 2.42 Risk-free interest rate 0.28 % 0.15 % Expected dividend yield — % — %

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Prepaid Expense and Other Assets, Current [Abstract]
Summary Of Prepaid Expenses and Other Current Assets	September 30, December 31, Prepaid research and development costs $ 4,882 $ 2,358 Government contract and grant agreement receivables 4,419 1,081 Prepaid insurance premiums 1,098 649 Other prepaid expenses 157 77 Total prepaid expenses and other current assets $ 10,556 $ 4,165

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Summary of Accrued Expenses	Accrued liabilities consist of the following (in thousands): September 30, December 31, Accrued research and development service fees $ 3,695 $ 801 Accrued compensation costs 1,798 2,069 Accrued professional fees 618 456 Accrued facilities operation expenses 122 173 Other accrued liabilities 19 111 Total accrued liabilities $ 6,252 $ 3,610

Net Loss (Income) Per Share o_2

Net Loss (Income) Per Share of Common Stock (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted income (Loss) Per Share for Common Stockholders	The following table sets forth the computation of basic and diluted net income (loss) per share for common stockholders (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Net (loss) $ (5,292 ) $ 3,444 $ (15,883 ) $ (21,751 ) Less: decrease in fair value of 2020 Warrants, net of tax — (8,827 ) — — Net loss – diluted $ (5,292 ) $ (5,383 ) $ (15,883 ) $ (21,751 ) Shares used in computing basic net (loss) income per share 39,332,721 27,809,169 35,914,327 21,069,057 Plus: dilutive effect of 2020 Warrants — 1,270 — — Shares used in computing diluted net loss per share 39,332,721 29,079,107 35,914,327 21,069,057 Basic net (loss) $ (0.13 ) $ 0.12 $ (0.44 ) $ (1.03 ) Diluted net loss per share $ (0.13 ) $ (0.19 ) $ (0.44 ) $ (1.03 )
Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding	The following table sets forth the potentially dilutive securities outstanding as of September 30, 2021 and 2020 that were excluded from the computation of diluted weighted average shares outstanding, as they would have been anti-dilutive: September 30, 2021 2020 Options to purchase common stock 2,950,551 1,864,631 Warrants to purchase common stock 10,926,733 12,354,580 Total 13,877,284 14,219,211

Commitments (Tables)

Commitments (Tables)	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Classification of Lease Liabilities	The balance sheet classification of the Company’s lease liabilities was as follows (in thousands): Description September 30, December 31, Operating lease liabilities: Current portion of lease liabilities $ 654 $ 644 Long-term portion of lease liabilities $ 2,700 $ 2,959
Summary of Future Minimum Lease Payments	As of September 30, 2021, the maturities of our operating lease liabilities were as follow s Amount October 1, 2021 - December 31, 2021 $ 171 Year ending December 31: 2022 693 2023 707 2024 721 2025 736 Thereafter 1,452 Total lease payments 4,480 Less: Present value adjustment (1,126 ) Operating lease liabilities 3,354
Lease, Cost	Lease costs under the terms of the Company’s leases for the three and nine months ended September 30, 2021 and 2020 were as follows (in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Operating lease cost (1) $ 154 $ 154 $ 461 $ 461 Variable lease costs (2) 46 43 111 89 Total lease cost $ 200 $ 197 $ 572 $ 550 (1) Operating lease payments included in the measurement of the Company’s lease liabilities are comprised of fixed payments according to the terms of the Company’s leases. (2) Variable lease payments consist of the Company’s utility costs billed by and paid to its landlord. Variable lease payments are presented as operating expenses in the Company’s Consolidated Statement of Operations in the same line item as expense arising from fixed lease payments and in net cash used in operating activities in the Company’s Statement of Cash Flows.

Capital Structure (Tables)

Capital Structure (Tables)	9 Months Ended
	Sep. 30, 2021
Federal Home Loan Banks [Abstract]
Summary of Common Stock Reserved for Future Issuance	The Company has reserved for future issuance the following number of shares of common stock as of September 30, 2021 and December 31, 2020: September 30, December 31, Outstanding options to purchase common stock 2,950,551 1,853,841 Outstanding warrants to purchase common stock 10,926,733 12,350,293 For future issuance under the 2014 Plan 26,774 41,079 13,904,058 14,245,213

Stock Warrants (Tables)

Stock Warrants (Tables)	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Schedule of Warrants Outstanding	As of September 30, 2021 and December 31, 2020, the Company had warrants to purchase the underlying common stock outstanding as shown in the table below. September 30, December 31, 2020 Warrants 8,819,904 8,842,464 2017 Warrants 1,599,645 1,599,645 2016 Warrants — 1,400,000 Pfizer Warrant 505,617 505,617 Other warrants (1) 1,567 2,567 Warrants to purchase common stock 10,926,733 12,350,293 Weighted-average exercise price per share $ 6.47 $ 9.14 (1) Other warrants are comprised of warrants issued prior to the Company’s initial public offering (“IPO”), generally in exchange for services rendered to the Company. The following table summarizes information regarding the Company’s warrants outstanding at September 30, 2021: Exercise Prices Shares Expiration Date £ 9,325,521 May 27, 2023 > $10.00 £ 1,599,645 July 25, 2022 > $20.00 1,567 October 17, 2021 – January 5, 2022 10,926,733

Stock Option and Incentive Pl_2

Stock Option and Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity	A summary of stock option activity for the nine months ended September 30, 2021, is summarized as follows: Number of Weighted Weighted Aggregate Options outstanding at December 31, 2020 1,853,841 $ 14.33 Granted 1,227,500 4.31 Exercised — — Expired (95,978 ) 46.18 Forfeited (34,812 ) 5.62 Options outstanding at September 30, 2021 2,950,551 9.22 8.10 $ 72,725 Vested and exercisable at September 30, 2021 1,324,857 13.74 6.86 $ 16,125
Assumptions to Compute Fair Value of Stock Option Grants	The following assumptions were used to compute the fair value of stock options granted during the period: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Risk free interest rate 0.81 % 0.27 % 0.83 % 1.15 % Expected dividend yield — — — — Expected term (in years) 6.12 6.12 5.99 6.03 Expected volatility 95.1 % 97.4 % 94.5 % 94.6 %

Organization and Description _2

Organization and Description of Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Mar. 22, 2021	Aug. 14, 2020	May 27, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Organization And Description Of Business [Line Items]
Accumulated deficit				$ (256,153)		$ (240,270)
Net cash used in operating activities				$ (32,557)	$ (25,672)
Number of shares issued			11,797,752
Stock issued during period, value		$ 150,000
Over-Allotment Option [Member]
Organization And Description Of Business [Line Items]
Number of shares issued	11,500,000
Sale of stock issue price per share	$ 5
Proceeds from initial public offer	$ 53,800

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Summary Of Significant Accounting Policies [Line Items]
Maturity period of highly liquid investments			three months or less
Realized gains or losses on marketable securities	$ 0	$ 0	$ 0	$ 0
Number of securities in unrealized loss position for more than 12 months	0		0		0
Grants receivable recognized	$ 3,700,000	$ 1,000,000	$ 7,700,000	$ 3,400,000
Government grants receivable	4,400,000		4,400,000		$ 1,100,000
Grant award funding remaining	$ 10,500,000		$ 10,500,000

Marketable Securities - Schedul

Marketable Securities - Schedule of Marketable Securities (Detail) - Corporate Debt [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Marketable Securities, Amortized Cost	$ 43,134	$ 27,026
Marketable Securities, Unrealized Gains	1	6
Marketable Securities, Unrealized Losses	(43)	(27)
Marketable Securities, Fair Value	$ 43,092	$ 27,005

Marketable Securities - Additio

Marketable Securities - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)Security
Marketable Securities [Abstract]
Marketable securities	$ 0
Maturity period classified current investments	less than one year.
Number of securities in unrealized loss position for less than one year | Security	23
Aggregate fair value of debt securities	$ 38,300

Fair Value Measurements - Infor

Fair Value Measurements - Information about Company's Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 0
Warrant liabilities	(12,194)	$ (29,404)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	14,116	12,921
Marketable securities	43,092	27,005
Total	57,208	39,926
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities	12,194	29,404
Total	$ 12,194	$ 29,404

Fair Value Measurements - Assum

Fair Value Measurements - Assumption Used to Determine Fair Value of Warrant Liability (Detail)	Sep. 30, 2021yr	Dec. 31, 2020yr
2016 Warrants [Member] | Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability		59.7
2016 Warrants [Member] | Remaining Contractual term (in years) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability		0.58
2016 Warrants [Member] | Risk-free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability		0.09
2017 Warrants [Member] | Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability	64.1	100.1
2017 Warrants [Member] | Remaining Contractual term (in years) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability	0.83	1.58
2017 Warrants [Member] | Risk-free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability	0.09	0.12
2020 Warrants [Member] | Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability	80.3	111.9
2020 Warrants [Member] | Remaining Contractual term (in years) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability	1.67	2.42
2020 Warrants [Member] | Risk-free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrant liability	0.28	0.15

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Company's Financial Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3) (Detail) - Warrant Liabilities [Member] - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period		$ 18,552	$ 44,350	$ 29,404	$ 6,069
Issuance of 2020 Warrants					31,392
Decrease in fair value	[1]	(6,358)	(10,689)	(17,210)	(3,800)
Balance at end of period		$ 12,194	$ 33,661	$ 12,194	$ 33,661
[1]	The change in fair values of the warrant liabilities is recorded in other income (expense) in the consolidated statement of operations.

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail)	Sep. 30, 2021
2016 Warrants [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Warrants and rights outstanding maturity date	Jul. 27, 2021

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Summary Of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid research and development costs	$ 4,882	$ 2,358
Government contract and grant agreement receivables	4,419	1,081
Prepaid insurance premiums	1,098	649
Other prepaid expenses	157	77
Total prepaid expenses and other current assets	$ 10,556	$ 4,165

Accrued Liabilities - Summary o

Accrued Liabilities - Summary of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued research and development service fees	$ 3,695	$ 801
Accrued compensation costs	1,798	2,069
Accrued professional fees	618	456
Accrued facilities operation expenses	122	173
Other accrued liabilities	19	111
Total accrued liabilities	$ 6,252	$ 3,610

Net Loss (Income) Per Share o_3

Net Loss (Income) Per Share of Common Stock - Additional Information (Detail)	3 Months Ended
	Sep. 30, 2020USD ($)shares
Warrant, Down Round Feature, (Increase) Decrease in Equity, Amount | $	$ 8,826,913
Incremental common shares attributable to the dilutive effect of treasury common shares | shares	1,269,938

Net Loss (Income) Per Share o_4

Net Loss (Income) Per Share of Common Stock - Schedule of Computation of Basic and Diluted Loss Per Share for Common Stockholders (Detail) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net (loss) income – basic	$ (5,292,000)	$ (5,396,000)	$ (5,195,000)	$ 3,444,000	$ (17,617,000)	$ (7,578,000)	$ (15,883,000)	$ (21,751,000)
Less: decrease in fair value of 2020 Warrants, net of tax				(8,826,913)
Net loss – diluted	$ (5,292,000)			$ (5,383,000)			$ (15,883,000)	$ (21,751,000)
Shares used in computing basic net (loss) income per share	39,332,721			27,809,169			35,914,327	21,069,057
Plus: dilutive effect of 2020 Warrants				1,270
Shares used in computing diluted net loss per share	39,332,721			29,079,107			35,914,327	21,069,057
Basic net (loss) income per share	$ (0.13)			$ 0.12			$ (0.44)	$ (1.03)
Diluted net loss per share	$ (0.13)			$ (0.19)			$ (0.44)	$ (1.03)

Net Loss (Income) Per Share o_5

Net Loss (Income) Per Share of Common Stock - Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted Average Shares Outstanding (Detail) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares	13,877,284	14,219,211
Employee Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares	2,950,551	1,864,631
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially antidilutive securities outstanding excluded from the computation of diluted weighted average shares	10,926,733	12,354,580

Commitments - Additional Inform

Commitments - Additional Information (Detail)	1 Months Ended
	Jan. 31, 2012ft²ExtensionOptions	Dec. 31, 2011ExtensionOptions	Dec. 31, 2010	Jan. 01, 2019
Loss Contingencies [Line Items]
Non-cancellable operating lease, expiration date		2027-12	2025-12
Extended lease agreement, date	2027-12
Number of lease extension options | ExtensionOptions	2	2
Lease renewal termination period	5 years	5 years
Area of space relinquished from lease agreement | ft²	10,912
Operating lease, discount rate, percent				9.93%

Commitments - Schedule of Class

Commitments - Schedule of Classification of Lease Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating lease liabilities:
Current portion of lease liabilities	$ 654	$ 644
Long-term portion of lease liabilities	$ 2,700	$ 2,959

Commitments - Maturities Of Ope

Commitments - Maturities Of Operating Lease Liabilities (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
October 1, 2021 - December 31, 2021	$ 171
2022	693
2023	707
2024	721
2025	736
Thereafter	1,452
Total lease payments	4,480
Less: Present value adjustment	(1,126)
Operating lease liabilities	$ 3,354

Commitments - Lease Cost (Detai

Commitments - Lease Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disclosure of Lease of Cost [Abstract]
Operating lease cost	$ 154	$ 154	$ 461	$ 461
Variable lease costs	46	43	111	89
Total lease cost	$ 200	$ 197	$ 572	$ 550

Capital Structure - Additional

Capital Structure - Additional Information (Detail)	Mar. 22, 2021USD ($)$ / sharesshares	May 27, 2020USD ($)$ / sharesshares	Jul. 25, 2017USD ($)	Jul. 27, 2016USD ($)	Sep. 30, 2021USD ($)shares	Sep. 30, 2020USD ($)	Dec. 31, 2020shares
Class of Stock [Line Items]
Common stock, shares authorized | shares					125,000,000		125,000,000
Number of shares issued | shares		11,797,752
Net proceeds received		$ 48,900,000
Gross Proceed		$ 3,000,000
Dividends declared or paid					$ 0
Issuance costs allocated to warrants						$ 2,175,000
Common stock, voting rights					The holders of shares of common stock are entitled to one vote for each share of common stock held at all meetings of stockholders and written actions in lieu of meetings.
Issuance of common stock for exercise of warrants, Shares | shares					22,560		5,850
2016 Warrants [Member]
Class of Stock [Line Items]
Warrants and rights outstanding maturity date					Jul. 27, 2021
Private Placement [Member]
Class of Stock [Line Items]
Public offering price, per unit | $ / shares		$ 4.45
Issuance of securities in private placement, Shares | shares		674,156
Follow-on Offering [Member]
Class of Stock [Line Items]
Public offering price, per unit | $ / shares		$ 4.45
Warrants to purchase shares of common stock | shares		8,848,314
Warrant exercise price per share | $ / shares		$ 4.90
Conversion ratio of common stock						0.75
Follow-on Offering [Member] | 2016 Warrants [Member]
Class of Stock [Line Items]
Fair value of warrants				$ 18,600,000
Issuance costs allocated to warrants				$ 1,600,000
Follow-on Offering [Member] | 2017 Warrants [Member]
Class of Stock [Line Items]
Fair value of warrants			$ 12,400,000
Issuance costs allocated to warrants			$ 900,000
Follow-on Offering [Member] | 2020 Warrants [Member]
Class of Stock [Line Items]
Fair value of warrants		$ 31,400,000
Issuance costs allocated to warrants		$ 2,200,000
Over-Allotment Option [Member]
Class of Stock [Line Items]
Number of shares issued | shares	11,500,000
Proceeds from initial public offer	$ 53,800,000
Sale of stock issue price per share | $ / shares	$ 5
Pfizer Warrants [Member]
Class of Stock [Line Items]
Warrants to purchase shares of common stock | shares		505,617
Warrant exercise price per share | $ / shares		$ 4.90

Capital Structure - Summary of

Capital Structure - Summary of Common Stock Reserved for Future Issuance (Detail) - shares	Sep. 30, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Common Stock reserved for future issuance	13,904,058	14,245,213
Two Thousand Fourteen Omnibus IncentivePlan [Member]
Class of Stock [Line Items]
Common Stock reserved for future issuance	26,774	41,079
Stock Options [Member]
Class of Stock [Line Items]
Common Stock reserved for future issuance	2,950,551	1,853,841
Warrants [Member]
Class of Stock [Line Items]
Common Stock reserved for future issuance	10,926,733	12,350,293

Stock Warrants - Schedule of Wa

Stock Warrants - Schedule of Warrants Outstanding (Detail) - $ / shares		9 Months Ended
		Sep. 30, 2021	Dec. 31, 2020
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants		10,926,733	12,350,293
Weighted-average exercise price per share		$ 6.47	$ 9.14
Other Warrants [Member]
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants	[1]	1,567	2,567
Pfizer [Member]
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants		505,617	505,617
Exercise Price Less Than or Equal to $10.00 [Member]
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants		9,325,521
Expiration Start Date		May 27, 2023
Exercise Price Greater Than $10.00 Lesser Than Equal To $20.00 [Member]
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants		1,599,645
Expiration Start Date		Jul. 25, 2022
Exercise Price Greater Than or Equal to $ 20.00 [Member]
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants		1,567
Expiration Start Date		Oct. 17, 2021
Expiration End Date		Jan. 5, 2022
Minimum [Member] | Exercise Price Less Than or Equal to $10.00 [Member]
Class of Warrant or Right [Line Items]
Exercise Prices		$ 10
Minimum [Member] | Exercise Price Greater Than $10.00 Lesser Than Equal To $20.00 [Member]
Class of Warrant or Right [Line Items]
Exercise Prices		10
Minimum [Member] | Exercise Price Greater Than or Equal to $ 20.00 [Member]
Class of Warrant or Right [Line Items]
Exercise Prices		20
Maximum [Member] | Exercise Price Greater Than or Equal to $ 20.00 [Member]
Class of Warrant or Right [Line Items]
Exercise Prices		$ 20
2016 Warrants [Member]
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants		0	1,400,000
2017 Warrants [Member]
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants		1,599,645	1,599,645
2020 Warrants [Member]
Class of Warrant or Right [Line Items]
Shares Underlying Outstanding Warrants		8,819,904	8,842,464
[1]	Other warrants are comprised of warrants issued prior to the Company’s initial public offering (“IPO”), generally in exchange for services rendered to the Company.

Stock Option and Incentive Pl_3

Stock Option and Incentive Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Jan. 01, 2021	Dec. 31, 2015	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Jul. 28, 2014	Apr. 29, 2014	Feb. 24, 2014	Feb. 26, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock reserved pursuant to the plan			13,904,058		13,904,058		14,245,213
Weighted average grant date fair value of options			$ 3.93	$ 5.66	$ 4.31	$ 9.77
Unrecognized compensation cost related to unvested stock options			$ 6.7		$ 6.7
Weighted average period of unvested stock options					2 years 6 months 29 days
Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense recognized			$ 0.9	$ 0.7	$ 2.4	$ 1.9
Amended and Restated 2008 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock reserved pursuant to the plan											157,143
Termination of service, Period					2 years
2008 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock reserved pursuant to the plan									235,714	185,714
Termination of service, Period					10 years
2014 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock reserved pursuant to the plan								57,143
Number of additional shares increases of common stock reserved pursuant to the plan	2,695,373
2014 Omnibus Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual increase of plan, percentage of common stock shares outstanding		4.00%

Stock Option and Incentive Pl_4

Stock Option and Incentive Plans - Summary of Stock Option Activity (Detail)	9 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Options, Options outstanding, Beginning balance | shares	1,853,841
Number of Options, Granted | shares	1,227,500
Number of Options, Exercised | shares	0
Number of Options, Expired | shares	(95,978)
Number of Options, Forfeited | shares	(34,812)
Number of Options, Options outstanding, Ending balance | shares	2,950,551
Number of Options, Vested and exercisable, Ending Balance | shares	1,324,857
Weighted Average Exercise Price, Options outstanding, Beginning balance | $ / shares	$ 14.33
Weighted Average Exercise Price, Granted | $ / shares	4.31
Weighted Average Exercise Price, Exercised | $ / shares
Weighted Average Exercise Price, Expired | $ / shares	46.18
Weighted Average Exercise Price, Forfeited | $ / shares	5.62
Weighted Average Exercise Price, Options outstanding, Ending balance | $ / shares	9.22
Weighted Average Exercise Price, Vested and exercisable, Ending balance | $ / shares	$ 13.74
Weighted Average Remaining Contractual Life (in years), Options outstanding	8 years 1 month 6 days
Weighted Average Remaining Contractual Life (in years), Vested and exercisable	6 years 10 months 9 days
Aggregate Intrinsic value, Options outstanding | $	$ 72,725
Aggregate Intrinsic value, Vested and exercisable | $	$ 16,125

Stock Option and Incentive Pl_5

Stock Option and Incentive Plans - Assumptions to Compute Fair Value of Stock Option Grants (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk free interest rate	0.81%	0.27%	0.83%	1.15%
Expected dividend yield
Expected term (in years)	6 years 1 month 13 days	6 years 1 month 13 days	5 years 11 months 26 days	6 years 10 days
Expected volatility	95.10%	97.40%	94.50%	94.60%