SCYNEXIS (SCYX) 10-Q 6 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 01, 2020
Cover [Abstract]
Entity Registrant Name	SCYNEXIS, Inc.
Trading Symbol	SCYX
Entity Central Index Key	0001178253
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Document Type	10-Q
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		10,940,119
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity File Number	001-36365
Entity Tax Identification Number	56-2181648
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	1 Evertrust Plaza
Entity Address, Address Line Two	13th Floor
Entity Address, City or Town	Jersey City
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07302-6548
City Area Code	201
Local Phone Number	884-5485
Document Quarterly Report	true
Document Transition Report	false
Title of Each Class	Common Stock, par value $0.001 per share
Name of Each Exchange on Which Registered	NASDAQ

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 29,494	$ 41,920
Short-term investments	0	6,494
Prepaid expenses and other current assets	2,762	3,988
Restricted cash	55	0
Total current assets	32,311	52,402
Other assets	573	812
Deferred offering costs	277	70
Restricted cash	218	273
Property and equipment, net	326	405
Operating lease right-of-use asset (See Note 7)	3,047	3,191
Total assets	36,752	57,153
Current liabilities:
Accounts payable	5,254	7,177
Accrued expenses	3,004	3,801
Operating lease liability, current portion (See Note 7)	47	36
Total current liabilities	8,305	11,014
Warrant liabilities	2,282	18,396
Convertible debt and derivative liabilities (See Note 6)	13,275	11,522
Operating lease liability (See Note 7)	3,332	3,326
Total liabilities	27,194	44,258
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value, authorized 5,000,000 shares as of September 30, 2020 and December 31, 2019; 0 shares issued and outstanding as of September 30, 2020 and December 31, 2019	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized as of September 30, 2020 and December 31, 2019; 10,798,119 and 9,741,372 shares issued and outstanding as of September 30, 2020 and December 31, 2019, respectively	10	10
Additional paid-in capital	293,450	284,313
Accumulated deficit	(283,902)	(271,428)
Total stockholders’ equity	9,558	12,895
Total liabilities and stockholders’ equity	$ 36,752	$ 57,153

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	10,798,119	9,741,372
Common stock, shares outstanding (in shares)	10,798,119	9,741,372

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 0	$ 0	$ 0	$ 121
Operating expenses:
Research and development	8,030	9,276	26,364	27,434
Selling, general and administrative	3,481	2,480	9,448	7,501
Total operating expenses	11,511	11,756	35,812	34,935
Loss from operations	(11,511)	(11,756)	(35,812)	(34,814)
Other (income) expense:
Loss on extinguishment of debt	0	0	806	1,045
Amortization of debt issuance costs and discount	311	306	910	879
Interest income	(5)	(170)	(188)	(680)
Interest expense	330	203	859	774
Other income	0	0	(386)	0
Other expense	20	0	602	0
Warrant liabilities fair value adjustment	(7,786)	(1,830)	(16,114)	2,643
Derivative liabilities fair value adjustment	(5,290)	(2,324)	(6,683)	(223)
Total other (income) expense	(12,420)	(3,815)	(20,194)	4,438
Income (loss) before taxes	909	(7,941)	(15,618)	(39,252)
Income tax benefit	0	0	(3,144)	0
Net income (loss)	$ 909	$ (7,941)	$ (12,474)	$ (39,252)
Net income (loss) per share attributable to common stockholders – basic
Net income (loss) per share – basic	$ 0.09	$ (1.43)	$ (1.23)	$ (7.44)
Net loss per share attributable to common stockholders – diluted
Net loss per share – diluted	$ (0.28)	$ (1.45)	$ (1.37)	$ (7.44)
Weighted average common shares outstanding – basic and diluted
Basic	10,627,618	5,569,739	10,129,098	5,278,757
Diluted	13,389,014	6,707,939	11,220,802	5,278,757

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (12,474)	$ (39,252)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	82	85
Stock-based compensation expense	1,220	1,387
Accretion of investments discount	0	(61)
Amortization of debt issuance costs and discount	910	879
Warrant liabilities fair value adjustment	(16,114)	2,643
Change in fair value of derivative liabilities	(6,683)	(223)
Noncash operating lease expense for right-of-use asset	144	127
Loss on extinguishment of debt	806	1,045
Noncash consideration associated with common stock purchase agreement	602	0
Changes in operating assets and liabilities:
Prepaid expenses, other assets, deferred costs, and other	1,482	6,485
Accounts payable, accrued expenses, and other	(2,757)	2,345
Deferred revenue	0	(121)
Net cash used in operating activities	(32,782)	(24,661)
Cash flows from investing activities:
Maturities of investments	20,713	54,700
Purchases of property and equipment	(4)	0
Purchases of investments	(14,235)	(38,504)
Net cash provided by investing activities	6,474	16,196
Cash flows from financing activities:
Proceeds from common stock issued	4,702	10,069
Payments of offering costs and underwriting discounts and commissions	(279)	(302)
Proceeds from common stock issuance under employee stock purchase plan	28	49
Repurchase of shares to satisfy tax withholdings	(75)	0
Proceeds from senior convertible notes	10,000	16,000
Payments of senior convertible notes issuance costs	(494)	(1,253)
Payment of loan payable expected to be refinanced	0	(15,973)
Net cash provided by financing activities	13,882	8,590
Net (decrease) increase in cash, cash equivalents, and restricted cash	(12,426)	125
Cash, cash equivalents, and restricted cash at beginning of period	42,193	11,767
Cash, cash equivalents, and restricted cash at end of period	29,767	11,892
Supplemental cash flow information:
Cash paid for interest	840	850
Cash received for interest	186	736
Noncash financing and investing activities:
Operating lease liabilities arising from obtaining right-of-use assets	0	3,365
Deferred offering costs reclassified to additional-paid-in capital	1	6
Common stock issued for settlement of senior convertible notes	2,784	2,984
Deferred offering and issuance costs included in accounts payable and accrued expenses	54	0
Common stock issued for Commitment Shares	$ 602	$ 0

Description of Business and Bas

Description of Business and Basis of Preparation	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Basis of Preparation	1. Description of Business and Basis of Preparation Organization SCYNEXIS, Inc. (“SCYNEXIS” or the “Company”) is a Delaware corporation formed on November 4, 1999. SCYNEXIS is a biotechnology company, headquartered in Jersey City, New Jersey, pioneering innovative medicines to potentially help millions of patients worldwide in need of new options to overcome and prevent difficult-to-treat and drug resistant infections. The Company is developing its lead product candidate, ibrexafungerp, as a broad-spectrum, intravenous (IV)/oral agent in late stage development for multiple indications, including the treatment of vulvovaginal candidiasis (VVC), also known as vaginal yeast infection, for which the Company filed a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) in October 2020. Additionally, the Company is developing ibrexafungerp for life-threatening invasive fungal infections in hospitalized patients. The Company has incurred significant losses and negative cash flows from operations since its initial public offering in May 2014 and expects to continue to incur losses and negative cash flows for the foreseeable future. As a result, the Company had an accumulated deficit of $283.9 million at September 30, 2020 and limited capital resources to fund ongoing operations. These capital resources primarily comprised cash and cash equivalents of $29.5 million at September 30, 2020. The Company believes its existing cash and cash equivalents may not be sufficient to enable it to meet its obligations and fund operations over the next twelve months without generating positive cash flows by raising additional capital from outside sources. While the Company plans to continue to pursue its plan to launch products and generate positive cash flows from operations, as well as pursue sources of additional capital from outside sources, These financial conditions raise substantial doubt about the Company’s ability to continue as a going concern. As noted in Note 8, the Company entered into a Common Stock Purchase Agreement with Aspire Capital, pursuant to which the Company has the right to sell to Aspire Capital from time to time in its sole discretion up to $20.0 million in shares of the Company’s common stock through October 2022. The number of shares issued would be determined based on the closing price of the Company’s common stock as of the date the Company elects to issue shares to Aspire Capital, however, the total number of shares the Company may issue to Aspire Capital under this agreement may not exceed 1,956,547 shares of the Company’s common stock (which is equal to approximately 19.99% of the Company’s total common stock outstanding on the date of the Common Stock Purchase Agreement) without obtaining shareholder approval prior to such issuances. The accompanying unaudited interim condensed consolidated financial information has been prepared assuming that the Company will continue as a going concern, which contemplates continuity of operations, the realization of assets and the satisfaction of liabilities in the normal course of business. The accompanying unaudited interim condensed consolidated financial information does not include any adjustments that might result from the outcome of this uncertainty. The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. Intercompany balances and transactions are eliminated in consolidation. Shelf Registration Filings On September 11, 2020, the Company filed a shelf registration statement on Form S-3 (File No. 333-248751) with the Securities and Exchange Commission (“SEC”), which was declared effective on October 1, 2020 (the “October 2020 Shelf Registration”). The October 2020 Shelf Registration contains two prospectuses: • a base prospectus which covers the offering, issuance and sale of such indeterminate number of shares of common stock and preferred stock, such indeterminate principal amount of debt securities, and such indeterminate number of warrants to purchase common stock, preferred stock and/or debt securities, which together shall have an aggregate initial offering price not to exceed $200.0 million; and • a prospectus covering the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $50.0 million of the Company’s common stock that may be issued and sold under a Controlled Equity Offering SM Sales Agreement with Cantor Fitzgerald & Co. (“Cantor”) and/or Controlled Equity Offering SM Sales Agreement with Ladenburg Thalmann & Co. Inc. (such agreements, the “Sales Agreements”). The common stock that may be offered, issued and sold by the Company under the Sales Agreements is included in the $200.0 million of securities that may be offered, issued and sold by the Company under the base prospectus. Upon termination of the Sales Agreements, any portion of the $50.0 million included in the Sales Agreements prospectus that is not sold pursuant to the Sales Agreements will be available for sale in other offerings pursuant to the base prospectus and a corresponding prospectus supplement, and if no shares are sold under the Sales Agreements, the full $200.0 million of securities may be sold in other offerings pursuant to the base prospectus. As of September 30, 2020, $200.0 million of the securities registered under the base prospectus are available to be offered, issued and sold by the Company. As of September 30, 2020, approximately $322.8 million of the securities registered under the Company’s effective shelf registrations, which include the October 2020 Shelf Registration and the Form S-3 shelf registration filed by the Company in August 2018 (effective September 14, 2018), are available to be offered, issued and sold by the Company. December 2019 Public Offering On December 12, 2019, shares of the Company’s common stock and warrants to purchase up to an aggregate of 3,888,888 shares of the Company’s common stock at a public offering price of $9.00 per share and accompanying warrant. Net proceeds from the December 2019 Public Offering were $32.5 million, after deducting the underwriting discount and offering expenses. April 2020 Note Purchase Agreement In April 2020, the Company entered into a Senior Convertible Note Purchase Agreement (“April 2020 Note Purchase Agreement”) with Puissance Life Science Opportunities Fund VI (“Puissance”). Pursuant to the April 2020 Note Purchase Agreement, on April 9, 2020, the Company issued and sold to Puissance $10.0 million aggregate principal amount of its 6.0% Senior Convertible Notes due 2026 (“April 2020 Notes”). See Note 5 for details. Common Stock Purchase Agreement On April 10, 2020, the Company entered into a Common Stock Purchase Agreement (the “Common Stock Purchase Agreement”) with Aspire Capital Fund, LLC, an Illinois limited liability company (“Aspire Capital”), pursuant to which the Company has the right to sell to Aspire Capital from time to time in its sole discretion up to $20.0 million in shares of the Company’s common stock over the next 30 months, subject to certain limitations and conditions set forth in the Common Stock Purchase Agreement. See Note 8 for details. New Jersey Technology Business Tax Certificate Transfer (NOL) Program The New Jersey Technology Business Tax Certificate Transfer (NOL) program, administered by the New Jersey Economic Development Authority, enables approved biotechnology companies to sell their unused net operating losses (“NOLs”) and research and development tax credits to unaffiliated, profitable corporate taxpayers in the State of New Jersey up to a maximum lifetime benefit of $15.0 million per business. For the nine months ended September 30, 2020, the Company recognized a $3.1 million income tax benefit for the sale of a portion of the Company’s unused New Jersey NOLs and research and development credits. As of September 30, 2020, the Company has received approximately $9.9 million under the program. Reverse Stock Split On July 16, 2020, the Company filed a Certificate of Amendment to its Amended and Restated Certificate of Incorporation (the “Amendment”), which became effective on Friday, July 17, 2020, (a) implementing a 1-for-10 On the effective date of July 17, 2020, the number of the Company’s issued and outstanding shares of common stock was decreased from 105,083,291 to 10,508,302 and the par value per common share remained unchanged. No fractional shares were issued as a result of the reverse stock split. presented in these unaudited condensed consolidated financial statements have been retroactively adjusted for the reverse stock split and certain items in the prior period financial statements have been revised to conform to the current presentation. The reverse stock split affected all shares of the Company’s common stock outstanding immediately prior to the effective time of the reverse stock split, as well as the number of shares of common stock available for issuance under the Company’s equity incentive plans. In addition, the reverse stock split effected a reduction in the number of shares of common stock issuable upon the conversion of outstanding convertible notes or upon the exercise of stock options or warrants outstanding. Unaudited Interim Condensed Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements and notes have been prepared in accordance with accounting principles generally accepted in the United States (“US GAAP”), as contained in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (the “Codification” or “ASC”) for interim financial information. In the opinion of management, the interim financial information includes all adjustments of a normal recurring nature necessary for a fair presentation of the results of operations, financial position, and cash flows. The results of operations for the three and nine months ended September 30, 2020, are not necessarily indicative of the results for the full year or the results for any future periods. These unaudited condensed consolidated financial statements should be read in conjunction with the financial statements and notes set forth in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on March 11, 2020. Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with US GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. Significant estimates include: determination of the fair value of stock-based compensation grants

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements and notes follow the same significant accounting policies as those described in the notes to the audited consolidated financial statements of the Company for the year ended December 31, 2019, except as described below. Basic and Diluted Net Income (Loss) per Share of Common Stock The Company calculates net income (loss) per common share in accordance with ASC Earnings Per Share Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net income (loss) $ 909 $ (7,941 ) $ (12,474 ) $ (39,252 ) Dilutive effect of convertible debt (4,649 ) (1,815 ) (2,917 ) — Net loss allocated to common shares $ (3,740 ) $ (9,756 ) $ (15,391 ) $ (39,252 ) Weighted average common shares outstanding – basic 10,627,618 5,569,739 10,129,098 5,278,757 Dilutive effect of stock options and restricted stock units 1,058 — — — Dilutive effect of convertible debt 2,760,338 1,138,200 1,091,704 — Weighted average common shares outstanding – diluted 13,389,014 6,707,939 11,220,802 5,278,757 Net loss per share – diluted $ (0.28 ) $ (1.45 ) $ (1.37 ) $ (7.44 ) The following potentially dilutive shares of common stock have not been included in the computation of diluted net loss per share for the three and nine months ended September 30, 2020 and 2019, as the result would be anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Warrants to purchase common stock associated with Solar loan agreement 12,243 12,243 12,243 12,243 Warrants to purchase common stock associated with June 2016 public offering 421,867 421,867 421,867 421,867 Warrants to purchase common stock associated with March 2018 public offering – Series 2 798,810 798,810 798,810 798,810 Outstanding stock options 808,855 518,870 817,855 518,870 Outstanding restricted stock units 80,137 96,762 80,137 96,762 Common stock associated with March 2019 Notes — — 1,138,200 1,138,200 Warrants to purchase common stock associated with December 2019 Public Offering 4,472,205 — 4,472,205 — Total 6,594,117 1,848,552 7,741,317 2,986,752 Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options and Derivatives and Hedging—Contracts in Entity’s Own Equity: Accounting for Convertible Instruments and Contracts in and Entity’s Own Equity Recently Adopted Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement

Short-term Investments

Short-term Investments	9 Months Ended
	Sep. 30, 2020
Investments Debt And Equity Securities [Abstract]
Short-term Investments	3. Short-term Investments The following table summarizes the held-to-maturity securities held at December 31, 2019 (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value As of December 31, 2019 U.S. government securities $ 1,996 $ 15 $ (14 ) $ 1,997 Commercial paper 998 — — 998 Overnight repurchase agreement 3,500 — — 3,500 Total short-term investments $ 6,494 $ 15 $ (14 ) $ 6,495 All held-to-maturity short-term investments at December 31, 2019 will mature in less than one year. The gross unrealized gains and losses for the Company’s commercial paper and overnight repurchase agreement are not significant. The Company carries short-term investments at amortized cost. The fair value of the short-term investments is determined based on “Level 1” inputs, which consist of quoted prices in active markets for identical assets.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2020
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	4 . Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): September 30, 2020 December 31, 2019 Prepaid research and development services $ 1,656 $ 3,043 Prepaid insurance 610 252 Other prepaid expenses 54 19 Other current assets 442 674 Total prepaid expenses and other current assets $ 2,762 $ 3,988

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Accrued Expenses	5 . Accrued Expenses Accrued expenses consisted of the following (in thousands): September 30, 2020 December 31, 2019 Accrued research and development expenses $ 915 $ 1,296 Accrued employee bonus compensation 1,152 1,798 Other accrued expenses 937 707 Total accrued expenses $ 3,004 $ 3,801

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Borrowings	6 . Borrowings April 2020 Note Purchase Agreement On April 9, 2020, the Company entered into the April 2020 Note Purchase Agreement with Puissance and issued and sold to Puissance $10.0 million aggregate principal amount of its April 2020 Notes, resulting in net proceeds of approximately $9.5 million after deducting $0.5 million for an advisory fee and other issuance costs The April 2020 Notes will bear interest at a rate of 6.0% per annum, payable semiannually in arrears on April 15 and October 15 of each year, beginning October 15, 2020. The April 2020 Notes will mature on April 15, 2026, unless earlier converted, redeemed or repurchased. The April 2020 Notes constitute general, senior unsecured obligations of the Company. As of September 30, 2020, the Company’s April 2020 Notes consists of the convertible debt balance of $1.5 million, presented net of the unamortized debt issuance costs allocated to the convertible debt of $0.1 million, and the bifurcated embedded conversion option derivative liability of $2.0 million. In connection with the Company’s issuance of its April 2020 Notes, the Company bifurcated the embedded conversion option, inclusive of the interest make-whole provision and make-whole fundamental change provision, and recorded the embedded conversion option as a long-term derivative liability in the Company’s balance sheet in accordance with ASC 815, Derivatives and Hedging In June 2020, Puissance converted $2.0 million of the April 2020 Notes for 316,461 shares of common stock. Upon conversion of the $2.0 million of the April 2020 Notes, the Company recognized a $0.8 million extinguishment loss which represents the difference between the total net carrying amount of the convertible debt and derivative liability of $2.0 million and the fair value of the consideration issued of $2.8 million. The Company estimated the fair value of the convertible debt and derivative liability for the April 2020 Notes using a binomial lattice valuation model and Level 3 inputs. At September 30, 2020, the fair value of the April 2020 Notes is $7.1 million. The holders of the April 2020 Notes may convert their April 2020 Notes at their option at any time prior to the close of business on the business day immediately preceding April 15, 2026 into shares of the Company’s common stock. The initial conversion rate is 111.1108 shares of common stock per $1,000 principal amount of the April 2020 Notes, which is equivalent to an initial conversion price of approximately $ 9.00 per share, and is subject to adjustment in certain events described in the April 2020 Note Purchase Agreement. Holders who convert may also be entitled to receive, under certain circumstances, an “interest make-whole payment” (as defined in the April 2020 Note Purchase Agreement) payable in shares of common stock. In addition, following certain corporate events that occur prior to the maturity date, the Company will, in certain circumstances, increase the conversion rate for a holder who elects to convert its April 2020 Notes in connection with such a corporate event. Unless the Company seeks and receives stockholder approval, the number of shares that the Company may deliver in connection with a conversion of the April 2020 Notes, including those delivered in connection with an “interest make-whole payment” or a “make-whole fundamental change” (each as defined in the April 2020 Note Purchase Agreement), will not exceed a cap of shares of common stock. On or after April 15, 2023, the Company has the right, at its election, to redeem all or any portion of the April 2020 Notes not previously converted if the last reported sale price per share of common stock exceeds 130% of the conversion price on each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice. The redemption price will be 100% of the principal amount of the April 2020 Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If a “fundamental change” (as defined in the April 2020 Note Purchase Agreement) occurs, then, subject to certain exceptions, the Company must offer to repurchase the April 2020 Notes for cash at a repurchase price of 100% of the principal amount of the April 2020 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the repurchase date. March 2019 Note Purchase Agreement On March 7, 2019, the Company entered into a Senior Convertible Note Purchase Agreement (the “March 2019 Note Purchase Agreement”) with Puissance. Pursuant to the March 2019 Note Purchase Agreement, on March 7, 2019, the Company issued and sold to Puissance $16.0 million aggregate principal amount of its 6.0% Senior Convertible Notes due 2025 (“March 2019 Notes”), resulting in $14.7 million in net proceeds after deducting $1.3 million for an advisory fee and other issuance costs. The Company used the net proceeds to pay the remaining outstanding Solar term loan in full and recorded a loss on debt extinguishment of $0.8 million As of September 30, 2020, the Company’s March 2019 Notes consists of the convertible debt balance of $9.1 million, presented net of the unamortized debt issuance costs allocated to the convertible debt of $0.4 million, and the bifurcated embedded conversion option derivative liability of $0.6 million. In connection with the Company’s issuance of its March 2019 Notes, the Company bifurcated the embedded conversion option, inclusive of the interest make-whole provision and make-whole fundamental change provision, and recorded the embedded conversion option as a long-term derivative liability in the Company’s balance sheet in accordance with ASC 815, Derivatives and Hedging In April 2019, Puissance converted $2.0 million of the March 2019 Notes for 162,600 shares of common stock. Upon conversion of the $2.0 million of the March 2019 Notes, the Company recognized a $0.2 million extinguishment loss which represents the difference between the total net carrying amount of the convertible debt and derivative liability of $2.8 million and the fair value of the consideration issued of $3.0 million. The Company estimated the fair value of the convertible debt and derivative liability for the March 2019 Notes using a binomial lattice valuation model and Level 3 inputs. At September 30, 2020, the fair value of the convertible debt and derivative liability for the March 2019 Notes is $10.1 million. The March 2019 Notes were issued and sold for cash at a purchase price equal to 100% of their principal amount, in reliance on the exemption from registration beginning September 15, 2019. The March 2019 Notes will mature on March 15, 2025 , unless earlier converted, redeemed or repurchased . The March 2019 Notes constitute general, senior unsecured obligations of the Company. The holder of the March 2019 Notes may convert their March 2019 Notes at their option at any time prior to the close of business on the business day immediately preceding March 15, 2025 into shares of the Company’s common stock. The initial conversion rate is 73.9096 shares of common stock per $1,000 principal amount of March 2019 Notes, which is equivalent to an initial conversion price of approximately $13.53 and is subject to adjustment in certain events described in the March 2019 Note Purchase Agreement. The Holder upon conversion may also be entitled to receive, under certain circumstances, an interest make-whole payment payable in shares of common stock. In addition, following certain corporate events that occur prior to the maturity date, the Company will, in certain circumstances, increase the conversion rate if the holder elects to convert its March 2019 Notes in connection with such a corporate event. Subject to adjustment in the conversion rate, the number of shares that the Company may deliver in connection with a conversion of the March 2019 Notes, including those delivered in connection with an interest make-whole payment, will not exceed a cap of 81 shares of common stock per $1,000 principal amount of the March 2019 Notes. On or after March 15, 2022, the Company has the right, at its election, to redeem all or any portion of the March 2019 Notes not previously converted if the last reported sale price per share of common stock exceeds 130% of the conversion price on each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice. The redemption price will be 100% of the principal amount of the March 2019 Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If a “fundamental change” (as defined in the March 2019 Note Purchase Agreement) occurs, then, subject to certain exceptions, the Company must offer to repurchase the March 2019 Notes for cash at a repurchase price of 100% of the principal amount of the March 2019 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the repurchase date. Solar Loan Agreement On September 30, 2016, the Company entered into a loan agreement with Solar Capital Ltd. (“Solar”), in its capacity as administrative and collateral agent and as lender. Pursuant to the loan agreement, Solar was providing the Company with a 48-month secured term loan in the amount of $15.0 million. The term loan bore interest at a floating rate equal to the LIBOR rate in effect plus 8.49%. The Solar term loan was paid in full in March 2019.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7 . Commitments and Contingencies Leases On March 1, 2018, the Company entered into a long-term lease agreement for approximately 19,275 square feet of office space in Jersey City, New Jersey, that the Company identified as an operating lease under ASC 842 (the “Lease”). The lease term is eleven years from August 1, 2018, the commencement date, with total lease payments of $7.3 million over the lease term. The Company has the option to renew for two consecutive five-year in the accompanying unaudited condensed consolidated balance sheets . The consideration in the Lease allocated to the single lease component includes the fixed payments for the right to use the office space as well as common area maintenance. The Lease also contains costs associated with certain expense escalation, property taxes, insurance, parking, and utilities which are all considered variable payments and are excluded from the operating lease liability. The incremental borrowing rate utilized approximated the prevailing market interest rate the Company would incur to borrow a similar amount equal to the total Lease payments on a collateralized basis over the term of the Lease . The following table summarizes certain quantitative information associated with the amounts recognized in the unaudited condensed consolidated financial statements for the Lease (dollars in thousands): Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Operating lease cost $ 166 $ 498 Variable lease cost 9 36 Total operating lease expense $ 175 $ 534 Cash paid for amounts included in the measurement of operating lease liability $ 114 $ 336 September 30, 2020 Remaining Lease term (years) 8.84 Discount rate 15 % Future minimum lease payments for the Lease as of September 30, 2020 are as follows (in thousands): September 30, 2020 2020 $ 170 2021 517 2022 527 2023 715 2024 730 Thereafter 3,533 Total $ 6,192 The presentations of the operating lease liability and right-of-use asset as of September 30, 2020 are as follows (in thousands): September 30, 2020 Present value of future minimum lease payments $ 3,379 Operating lease liability, current portion $ 47 Operating lease liability, long-term portion 3,332 Total operating lease liability $ 3,379 Difference between future minimum lease payments and discounted cash flows $ 2,813 Operating lease right-of-use asset $ 3,047 License Arrangement with Potential Future Expenditures As of September 30, 2020, the Company had a license arrangement with Merck Sharp & Dohme Corp., or Merck, that involves potential future expenditures. Under the license arrangement, the Company exclusively licensed from Merck its rights to ibrexafungerp in the field of human health. Ibrexafungerp is the Company’s lead product candidate. Pursuant to the terms of the license agreement, Merck is eligible to receive milestone payments from the Company that could total $19.0 million upon occurrence of specific events, including initiation of a Phase 3 clinical study, new drug application, and marketing approvals in each of the U.S., major European markets and Japan. In addition, Merck is eligible to receive tiered royalties from the Company based on a percentage of worldwide net sales of ibrexafungerp. The aggregate royalty percentages are mid- to high-single digits. In December 2014, the Company and Merck entered into an amendment to the license agreement that deferred the remittance of a milestone payment due to Merck, such that no amount would be due upon initiation of the first Phase 2 clinical trial of a product containing the ibrexafungerp compound (the “ Deferred Milestone ” ). The amendment also increased, in an amount equal to the Deferred Milestone, the milestone payment that would be due upon initiation of the first Phase 3 clinical trial of a product containing the ibrexafungerp compound. In December 2016 and January 2018, the Company entered into second and third amendments, respectively, to the license agreement with Merck which clarified what would constitute the initiation of a Phase 3 clinical trial for the purpose of milestone payment. Except as described above, all other terms and provisions of the license agreement remain in full force and effect. In January 2019, a milestone payment became due to Merck as a result of the initiation of the VANISH Phase 3 VVC program and was paid in March 2019. The milestone payment was recognized in the unaudited condensed consolidated statement of operations in research and development expense for the nine months ended September 30, 20 1 9 and is included in cash used in operating activities on the statement of cash flows. Clinical Development Arrangements The Company has entered into, and expects to continue to enter into, contracts in the normal course of business with various third parties who support its clinical trials, preclinical research studies, and other services related to its development activities. The scope of the services under these agreements can generally be modified at any time, and the agreement can be terminated by either party after a period of notice and receipt of written notice.

Stockholder's Equity

Stockholder's Equity	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stockholder's Equity	8 . Stockholders’ Equity Authorized, Issued, and Outstanding Common Stock The Company’s authorized common stock has a par value of $0.001 per share and consists of 100,000,000 shares as of September 30, 2020, and December 31, 2019; 10,798,119 and 9,741,372 shares were issued and outstanding at September 30, 2020, and December 31, 2019, respectively. On July 16, 2020, the Company filed a Certificate of Amendment to its Amended and Restated Certificate of Incorporation (the “Amendment”), which became effective on Friday, July 17, 2020, (a) implementing a 1-for- 10 The reverse stock split affected all shares of the Company’s common stock outstanding immediately prior to the effective time of the reverse stock split, as well as the number of shares of common stock available for issuance under the Company’s equity incentive plans. In addition, the reverse stock split effected a reduction in the number of shares of common stock issuable upon the conversion of outstanding convertible notes or upon the exercise of stock options or warrants outstanding. No fractional shares were issued as a result of the reverse stock split. The following table summarizes common stock share activity for the three and nine months ended September 30, 2020 and 2019 (dollars in thousands): Three Months Ended September 30, 2020 Shares of Common Stock Common Stock Additional Paid-in Capital Accumulated Deficit Total Stockholders’ Equity Balance, June 30, 2020 10,478,927 $ 10 $ 291,134 $ (284,811 ) $ 6,333 Net income — — — 909 909 Stock-based compensation expense — — 399 — 399 Common stock issued, net of expenses 315,939 — 1,909 — 1,909 Common stock issued through employee stock purchase plan 2,284 — 9 — 9 Common stock issued for vested restricted stock units 969 — (1 ) — (1 ) Balance, September 30, 2020 10,798,119 $ 10 $ 293,450 $ (283,902 ) $ 9,558 Nine Months Ended September 30, 2020 Shares of Common Stock Common Stock Additional Paid-in Capital Accumulated Deficit Total Stockholders’ Equity Balance, December 31, 2019 9,741,372 $ 10 $ 284,313 $ (271,428 ) $ 12,895 Net loss — — — (12,474 ) (12,474 ) Stock-based compensation expense — — 1,220 — 1,220 Common stock issued through employee stock purchase and stock option plans 4,652 — 28 — 28 Common stock issued, net of expenses 647,504 — 4,578 — 4,578 Common stock issued for conversion of April 2020 Notes 316,461 — 2,784 — 2,784 Common stock issued for Commitment Shares 70,910 — 602 — 602 Common stock issued for vested restricted stock units 17,220 — (75 ) — (75 ) Balance, September 30, 2020 10,798,119 $ 10 $ 293,450 $ (283,902 ) $ 9,558 Three Months Ended September 30, 2019 Shares of Common Stock Common Stock Additional Paid-in Capital Accumulated Deficit Total Stockholders’ Equity Balance, June 30, 2019 5,452,011 $ 5 $ 259,426 $ (249,029 ) $ 10,402 Net loss — — — (7,941 ) (7,941 ) Stock-based compensation expense — — 449 — 449 Common stock issued through employee stock purchase plan 1,758 — 17 — 17 Common stock issued, net of expenses 279,911 — 3,206 — 3,206 Common stock issued for exercise of stock options 2,250 — 12 — 12 Common stock issued for vested restricted stock units 312 — (2 ) — (2 ) Balance, September 30, 2019 5,736,242 $ 5 $ 263,108 $ (256,970 ) $ 6,143 Nine Months Ended September 30, 2019 Shares of Common Stock Common Stock Additional Paid-in Capital Accumulated Deficit Total Stockholders’ Equity Balance, December 31, 2018 4,797,198 $ 5 $ 248,938 $ (217,718 ) $ 31,225 Net loss — — — (39,252 ) (39,252 ) Stock-based compensation expense — — 1,387 — 1,387 Common stock issued through employee stock purchase plan 3,684 — 37 — 37 Common stock issued, net of expenses 768,658 — 9,761 — 9,761 Common stock issued for conversion of March 2019 Notes 162,600 — 2,984 — 2,984 Common stock issued for exercise of stock options 2,250 — 12 — 12 Common stock issued for vested restricted stock units 1,852 — (11 ) — (11 ) Balance, September 30, 2019 5,736,242 $ 5 $ 263,108 $ (256,970 ) $ 6,143 Shares Reserved for Future Issuance The Company had reserved shares of common stock for future issuance as follows: September 30, 2020 December 31, 2019 Outstanding stock options 817,855 526,070 Outstanding restricted stock units 80,137 96,637 Warrants to purchase common stock associated with June 2016 Public Offering 421,867 421,867 Warrants to purchase common stock associated with March 2018 Public Offering – Series 2 798,810 798,810 Warrants to purchase common stock associated with December 2019 Public Offering 4,472,205 4,472,205 Option to purchase common stock associated with December 2019 Public Offering — 583,333 Warrants to purchase common stock associated with Solar loan agreement 12,243 12,243 For possible future issuance for the conversion of the March 2019 Notes 1,138,200 1,138,200 For possible future issuance for the conversion of the April 2020 Notes 1,622,138 — For possible future issuance under 2014 Equity Incentive Plan (Note 9) 161,776 55,478 For possible future issuance under Employee Stock Purchase Plan 5,895 7,423 For possible future issuance under 2015 Inducement Award Plan (Note 9) 14,050 31,550 Total common shares reserved for future issuance 9,545,176 8,143,816 Common Stock Purchase Agreement On April 10, 2020, the Company entered into the Common Stock Purchase Agreement with Aspire Capital pursuant to which the Company has the right to sell to Aspire Capital from time to time in its sole discretion up to $20.0 million in shares of the Company’s common stock over the next 30 months, subject to certain limitations and conditions set forth in the Common Stock Purchase Agreement. The aggregate number of shares that we can sell to Aspire Capital under the Common Stock Purchase Agreement may in no case exceed 1,956,547 shares of the Company’s common stock (which is equal to approximately 19.99% of the common stock outstanding on the date of the Common Stock Purchase Agreement), including the 70,910 commitment shares (the Exchange Cap), unless either (a) shareholder approval is obtained to issue more, in which case the Exchange Cap will not apply, or (b) the average purchase price of all shares sold under the Common Stock Purchase Agreement exceeds $8.461; provided that at no time shall Aspire Capital (together with its affiliates) beneficially own more than 19.99% of the Company’s common stock. During the three and nine months ended September 30, 2020, the Company sold 125,000 shares of its common stock under the Common Stock Purchase Agreement for gross proceeds of $0.6 million. Under the Common Stock Purchase Agreement, on any trading day selected by the Company, the Company has the right, in its sole discretion, to present Aspire Capital with a purchase notice (each, a “Purchase Notice”), directing Aspire Capital (as principal) to purchase up to 25,000 shares of Common Stock per business day, up to $20.0 million of common stock in the aggregate at a per share price (the “Purchase Price”) equal to the lesser of: • the lowest sale price of Common Stock on the purchase date; or • the arithmetic average of the three (3) lowest closing sale prices for Common Stock during the ten (10) consecutive trading days ending on the trading day immediately preceding the purchase date. The Company and Aspire Capital also may mutually agree to increase the number of shares that may be sold to as much as an additional 200,000 shares per business day. In addition, on any date on which the Company submits a Purchase Notice to Aspire Capital in an amount equal to at least 25,000 shares, the Company also has the right, in its sole discretion, to present Aspire Capital with a volume-weighted average price purchase notice (each, a “VWAP Purchase Notice”) directing Aspire Capital to purchase an amount of stock equal to up to 30% of the aggregate shares of Common Stock traded on its principal market on the next trading day (the “VWAP Purchase Date”), subject to a maximum number of shares the Company may determine. The purchase price per share pursuant to such VWAP Purchase Notice is generally the lessor of (i) the closing sale price on the VWAP Purchase Date, or (ii) 97% of the volume-weighted average price for common stock traded on its principal market on the VWAP Purchase Date. The Purchase Price will be adjusted for any reorganization, recapitalization, non-cash dividend, stock split, or other similar transaction occurring during the period(s) used to compute the Purchase Price. The Company may deliver multiple Purchase Notices and VWAP Purchase Notices to Aspire Capital from time to time during the term of the Common Stock Purchase Agreement, so long as the most recent purchase has been completed. The Common Stock Purchase Agreement provides that the Company and Aspire Capital shall not effect any sales under the Common Stock Purchase Agreement on any purchase date where the closing sale price of common stock is less than $ 0.25 . There are no trading volume requirements or restrictions under the Common Stock Purchase Agreement, and the Company will control the timing and amount of sales of c ommon s tock to Aspire Capital. Aspire Capital has no right to require any sales by the Company, but is obligated to make purchases from the Company as directed by the Company in accordance with the Common Stock Purchase Agreement. There are no limitations on use of proceeds, financial or business covenants, restrictions on future fundings, rights of first refusal, participation rights, penalties or liquidated damages in the Common Stock Purchase Agreement. In consideration for entering into the Common Stock Purchase Agreement, concurrently with the execution of the Common Stock Purchase Agreement, the Company issued to Aspire Capital shares of common stock (the “Commitment Shares”). The fair value of the Commitment Shares of $ 0.6 million was recognized in other expense in the unaudited condensed consolidated statements of operations for the nine months ended September 30, 2020 . The Common Stock Purchase Agreement may be terminated by the Company at any time, at its discretion, without any cost to the Company. Aspire Capital has agreed that neither it nor any of its agents, representatives and affiliates shall engage in any direct or indirect short-selling or hedging of c ommon s tock during any time prior to the termination of the Common Stock Purchase Agreement. Any proceeds that the Company receives under the Common Stock Purchase Agreement are expected to be used for general corporate purposes, including working capital. Convertible Debt and Derivative Liabilities In connection with the Company’s issuances of its April 2020 Notes and March 2019 Notes, the Company bifurcated the embedded conversion options, inclusive of the interest make-whole provisions and make-whole fundamental change provisions, and recorded the embedded conversion options as long-term derivative liabilities in the Company’s balance sheet in accordance with ASC 815, Derivatives and Hedging Warrants Associated with June 2016, March 2018, and December 2019 Public Offerings The outstanding warrants associated with the June 2016, March 2018, and December 2019 public offerings contain a provision where the warrant holder has the option to receive cash, equal to the Black-Scholes fair value of the remaining unexercised portion of the warrant, as cash settlement in the event that there is a fundamental transaction (contractually defined to include various merger, acquisition or stock transfer activities). Due to this provision, ASC 480, Distinguishing Liabilities from Equity, Warrant Associated with Solar Loan Agreement On the closing date of the Company’s previous loan agreement with Solar, pursuant to the loan agreement the Company issued to Solar the warrant to purchase an aggregate of up to 12,243 shares of the Company’s common stock at an exercise price of $36.754 per share. The warrant will expire five years from the date of the grant. The warrant was classified as equity and recorded at its relative fair value at issuance in the stockholders’ equity section of the balance sheet.

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation	9 . Stock-based Compensation Pursuant to the terms of the Company’s 2014 Equity Incentive Plan (“2014 Plan”), on January 1, 2020 and 2019, the Company automatically added 389,654 and 191,887 shares to the total number shares of common stock available for future issuance under the 2014 Plan, respectively. As of September 30, 2020, there were 161,776 shares of common stock available for future issuance under the 2014 Plan. As of September 30, 2020, there were 14,050 shares of common stock available for future issuance under the Company’s 2015 Inducement Award Plan (“2015 Plan”). During the nine months ended September 30, 2020 and 2019, there were 17,500 and 11,500 granted options of the Company’s common stock under the 2015 Plan, respectively. The activity for the Company’s 2009 Stock Option Plan, 2014 Plan, and 2015 Plan, for the nine months ended September 30, 2020, is summarized as follows: Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value ($000) Outstanding — December 31, 2019 526,070 $ 30.55 7.62 $ 60 Granted 324,437 $ 8.39 Exercised (166 ) $ 8.60 Forfeited/Cancelled (32,486 ) $ 26.46 Outstanding — September 30, 2020 817,855 $ 21.92 7.80 $ — Exercisable — September 30, 2020 415,309 $ 33.06 6.81 $ — Vested or expected to vest — September 30, 2020 817,855 $ 21.92 7.80 $ — Restricted stock unit (“RSU”) activity under the 2014 Plan and 2015 Plan for the nine months ended September 30, 2020, is summarized as follows: Number of Shares Weighted Average Grant Date Fair Value Per Share Non-vested at December 31, 2019 96,637 $ 14.18 Granted 25,695 $ 8.63 Vested (25,009 ) $ 14.59 Forfeited/Cancelled (17,186 ) $ 12.67 Non-vested at September 30, 2020 80,137 $ 12.60 The fair value of RSUs is based on the market price of the Company’s common stock on the date of grant. RSUs generally vest 25% annually over a four-year Upon vesting, the RSUs are net share settled to cover the required withholding tax with the remaining shares issued to the holder. The Company recognizes compensation expense for such awards ratably over the corresponding vesting period. Compensation Cost The compensation cost that has been charged against income for stock awards under the 2014 Plan and the 2015 Plan was $0.4 million for both the three months ended September 30, 2020 and 2019, and $1.2 million and $1.4 million for the nine months ended September 30, 2020 and 2019, respectively. The total income tax benefit recognized in the statements of operations for share-based compensation arrangements was zero for each of the three and nine months ended September 30, 2020 and 2019. Stock-based compensation expense related to stock options is included in the following line items in the accompanying unaudited condensed consolidated statements of operations (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development $ 130 $ 148 $ 394 $ 471 Selling, general and administrative 269 301 826 916 Total $ 399 $ 449 $ 1,220 $ 1,387

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	10 . Fair Value Measurements The carrying amounts of certain financial instruments, including cash and cash equivalents, restricted cash, accounts receivable, prepaid expenses and other current assets, accounts payable, and accrued expenses approximate their respective fair values due to the short-term nature of such instruments. Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company evaluates its financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level in which to classify them for each reporting period. This determination requires significant judgments to be made. The following table summarizes the conclusions reached as of September 30, 2020 and December 31, 2019 for financial instruments measured at fair value on a recurring basis (in thousands): Fair Value Hierarchy Classification Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2020 Cash $ 805 $ 805 — — Restricted cash 273 273 — — Money market funds 28,689 28,689 — — Total assets $ 29,767 $ 29,767 — — Warrant liabilities $ 2,282 — — $ 2,282 Derivative liabilities 2,606 — — 2,606 Total liabilities $ 4,888 — — $ 4,888 December 31, 2019 Cash $ 23 $ 23 — — Restricted cash 273 273 — — Money market funds 41,897 41,897 — — Total assets $ 42,193 $ 42,193 — — Warrant liabilities $ 18,396 — — $ 18,396 Derivative liability 3,192 — — 3,192 Total liabilities $ 21,588 — — $ 21,588 The Company measures cash equivalents at fair value on a recurring basis. The fair value of cash equivalents is determined based on “Level 1” inputs, which consist of quoted prices in active markets for identical assets. Level 3 financial liabilities consist of the warrant liabilities for which there is no current market such that the determination of fair value requires significant judgment or estimation. Changes in fair value measurements categorized within Level 3 of the fair value hierarchy are analyzed each period based on changes in estimates or assumptions and recorded as appropriate. The Company uses the Black-Scholes option valuation model to value the Level 3 warrant liabilities at inception and on subsequent valuation dates. This model incorporates transaction details such as the Company’s stock price, contractual terms, maturity, risk free rates, as well as volatility. The unobservable input for all of the Level 3 warrant liabilities includes volatility. The historical volatility of the Company, using its closing common stock prices, is utilized to reflect future volatility over the expected term of the warrants. At September 30, 2020, the range and weighted average of the Level 3 volatilities utilized in the Black-Scholes model to fair value the warrant liabilities were 69.1% to 75.7% and 71.1%, respectively. Additionally, the expected term associated with the December 2019 Public Offering warrants is an unobservable unit given that the expiration of the warrants is the earlier of (i) such date that is six months after the Company publicly announces the approval from the U.S. Food and Drug Administration for ibrexafungerp for the treatment of vulvovaginal candidiasis and (ii) June 12, 2023. 1.16 to 2.7 years The Company uses the binomial lattice valuation model to value the Level 3 derivative liabilities at inception and on subsequent valuation dates. This model incorporates transaction details such as the Company’s stock price, contractual terms, dividend yield, risk-free rate, historical volatility, credit rating, market credit spread, and estimated effective yield. The unobservable inputs associated with the Level 3 derivative liabilities are adjusted equity volatility, market credit spread, and estimated yield. As of September 30, 2020, these inputs were 55.5%, 1,606 basis points, and 16.4%, respectively. The range of volatilities were 54.4% to 59.4%. The senior convertible notes are initially fair valued using the binomial lattice model and with the straight debt fair value calculated using the discounted cash flow method. The discount for lack of marketability, 5.60% as of September 30, 2020, is applied to the value of the March 2019 Notes. The residual difference represents the fair value of the embedded derivative liabilities and the fair value of the embedded derivative liabilities are reassessed using the binomial lattice valuation model on a quarterly basis A reconciliation of the beginning and ending balances for liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) is as follows (in thousands): Warrant Liabilities Balance – December 31, 2019 $ 18,396 Gain adjustment to fair value (16,114 ) Balance – September 30, 2020 $ 2,282 Derivative Liabilities Balance – December 31, 2019 $ 3,192 Bifurcated embedded conversion option associated with April 2020 Notes 8,110 Adjustment for partial conversion of April 2020 Notes (1,612 ) Gain adjustment to fair value (7,084 ) Balance – September 30, 2020 $ 2,606

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basic and Diluted Net Loss per Share of Common Stock	Basic and Diluted Net Income (Loss) per Share of Common Stock The Company calculates net income (loss) per common share in accordance with ASC Earnings Per Share Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net income (loss) $ 909 $ (7,941 ) $ (12,474 ) $ (39,252 ) Dilutive effect of convertible debt (4,649 ) (1,815 ) (2,917 ) — Net loss allocated to common shares $ (3,740 ) $ (9,756 ) $ (15,391 ) $ (39,252 ) Weighted average common shares outstanding – basic 10,627,618 5,569,739 10,129,098 5,278,757 Dilutive effect of stock options and restricted stock units 1,058 — — — Dilutive effect of convertible debt 2,760,338 1,138,200 1,091,704 — Weighted average common shares outstanding – diluted 13,389,014 6,707,939 11,220,802 5,278,757 Net loss per share – diluted $ (0.28 ) $ (1.45 ) $ (1.37 ) $ (7.44 ) The following potentially dilutive shares of common stock have not been included in the computation of diluted net loss per share for the three and nine months ended September 30, 2020 and 2019, as the result would be anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Warrants to purchase common stock associated with Solar loan agreement 12,243 12,243 12,243 12,243 Warrants to purchase common stock associated with June 2016 public offering 421,867 421,867 421,867 421,867 Warrants to purchase common stock associated with March 2018 public offering – Series 2 798,810 798,810 798,810 798,810 Outstanding stock options 808,855 518,870 817,855 518,870 Outstanding restricted stock units 80,137 96,762 80,137 96,762 Common stock associated with March 2019 Notes — — 1,138,200 1,138,200 Warrants to purchase common stock associated with December 2019 Public Offering 4,472,205 — 4,472,205 — Total 6,594,117 1,848,552 7,741,317 2,986,752
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options and Derivatives and Hedging—Contracts in Entity’s Own Equity: Accounting for Convertible Instruments and Contracts in and Entity’s Own Equity Recently Adopted Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Schedule of Diluted Net Loss Per Common Share	Diluted net loss per common share for the three and nine months ended September 30, 2020 and 2019 was determined as follows (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net income (loss) $ 909 $ (7,941 ) $ (12,474 ) $ (39,252 ) Dilutive effect of convertible debt (4,649 ) (1,815 ) (2,917 ) — Net loss allocated to common shares $ (3,740 ) $ (9,756 ) $ (15,391 ) $ (39,252 ) Weighted average common shares outstanding – basic 10,627,618 5,569,739 10,129,098 5,278,757 Dilutive effect of stock options and restricted stock units 1,058 — — — Dilutive effect of convertible debt 2,760,338 1,138,200 1,091,704 — Weighted average common shares outstanding – diluted 13,389,014 6,707,939 11,220,802 5,278,757 Net loss per share – diluted $ (0.28 ) $ (1.45 ) $ (1.37 ) $ (7.44 )
Summary of Antidilutive Securities Excluded from Computation of Weighted Average Common Stock Outstanding	The following potentially dilutive shares of common stock have not been included in the computation of diluted net loss per share for the three and nine months ended September 30, 2020 and 2019, as the result would be anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Warrants to purchase common stock associated with Solar loan agreement 12,243 12,243 12,243 12,243 Warrants to purchase common stock associated with June 2016 public offering 421,867 421,867 421,867 421,867 Warrants to purchase common stock associated with March 2018 public offering – Series 2 798,810 798,810 798,810 798,810 Outstanding stock options 808,855 518,870 817,855 518,870 Outstanding restricted stock units 80,137 96,762 80,137 96,762 Common stock associated with March 2019 Notes — — 1,138,200 1,138,200 Warrants to purchase common stock associated with December 2019 Public Offering 4,472,205 — 4,472,205 — Total 6,594,117 1,848,552 7,741,317 2,986,752

Short-term Investments (Tables)

Short-term Investments (Tables)	9 Months Ended
	Sep. 30, 2020
Investments Debt And Equity Securities [Abstract]
Held-to-maturity Securities	The following table summarizes the held-to-maturity securities held at December 31, 2019 (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value As of December 31, 2019 U.S. government securities $ 1,996 $ 15 $ (14 ) $ 1,997 Commercial paper 998 — — 998 Overnight repurchase agreement 3,500 — — 3,500 Total short-term investments $ 6,494 $ 15 $ (14 ) $ 6,495

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): September 30, 2020 December 31, 2019 Prepaid research and development services $ 1,656 $ 3,043 Prepaid insurance 610 252 Other prepaid expenses 54 19 Other current assets 442 674 Total prepaid expenses and other current assets $ 2,762 $ 3,988

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following (in thousands): September 30, 2020 December 31, 2019 Accrued research and development expenses $ 915 $ 1,296 Accrued employee bonus compensation 1,152 1,798 Other accrued expenses 937 707 Total accrued expenses $ 3,004 $ 3,801

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Summary of Quantitative Information Associated with Amounts Recognized in Unaudited Condensed Consolidated Financial Statements for Lease	The following table summarizes certain quantitative information associated with the amounts recognized in the unaudited condensed consolidated financial statements for the Lease (dollars in thousands): Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Operating lease cost $ 166 $ 498 Variable lease cost 9 36 Total operating lease expense $ 175 $ 534 Cash paid for amounts included in the measurement of operating lease liability $ 114 $ 336 September 30, 2020 Remaining Lease term (years) 8.84 Discount rate 15 %
Future Minimum Lease Payments	Future minimum lease payments for the Lease as of September 30, 2020 are as follows (in thousands): September 30, 2020 2020 $ 170 2021 517 2022 527 2023 715 2024 730 Thereafter 3,533 Total $ 6,192
Presentation of Operating Lease Liability and Right-of-Use Asset	The presentations of the operating lease liability and right-of-use asset as of September 30, 2020 are as follows (in thousands): September 30, 2020 Present value of future minimum lease payments $ 3,379 Operating lease liability, current portion $ 47 Operating lease liability, long-term portion 3,332 Total operating lease liability $ 3,379 Difference between future minimum lease payments and discounted cash flows $ 2,813 Operating lease right-of-use asset $ 3,047

Stockholder's Equity (Tables)

Stockholder's Equity (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Summary of Common Stock Shares Activity	The following table summarizes common stock share activity for the three and nine months ended September 30, 2020 and 2019 (dollars in thousands): Three Months Ended September 30, 2020 Shares of Common Stock Common Stock Additional Paid-in Capital Accumulated Deficit Total Stockholders’ Equity Balance, June 30, 2020 10,478,927 $ 10 $ 291,134 $ (284,811 ) $ 6,333 Net income — — — 909 909 Stock-based compensation expense — — 399 — 399 Common stock issued, net of expenses 315,939 — 1,909 — 1,909 Common stock issued through employee stock purchase plan 2,284 — 9 — 9 Common stock issued for vested restricted stock units 969 — (1 ) — (1 ) Balance, September 30, 2020 10,798,119 $ 10 $ 293,450 $ (283,902 ) $ 9,558 Nine Months Ended September 30, 2020 Shares of Common Stock Common Stock Additional Paid-in Capital Accumulated Deficit Total Stockholders’ Equity Balance, December 31, 2019 9,741,372 $ 10 $ 284,313 $ (271,428 ) $ 12,895 Net loss — — — (12,474 ) (12,474 ) Stock-based compensation expense — — 1,220 — 1,220 Common stock issued through employee stock purchase and stock option plans 4,652 — 28 — 28 Common stock issued, net of expenses 647,504 — 4,578 — 4,578 Common stock issued for conversion of April 2020 Notes 316,461 — 2,784 — 2,784 Common stock issued for Commitment Shares 70,910 — 602 — 602 Common stock issued for vested restricted stock units 17,220 — (75 ) — (75 ) Balance, September 30, 2020 10,798,119 $ 10 $ 293,450 $ (283,902 ) $ 9,558 Three Months Ended September 30, 2019 Shares of Common Stock Common Stock Additional Paid-in Capital Accumulated Deficit Total Stockholders’ Equity Balance, June 30, 2019 5,452,011 $ 5 $ 259,426 $ (249,029 ) $ 10,402 Net loss — — — (7,941 ) (7,941 ) Stock-based compensation expense — — 449 — 449 Common stock issued through employee stock purchase plan 1,758 — 17 — 17 Common stock issued, net of expenses 279,911 — 3,206 — 3,206 Common stock issued for exercise of stock options 2,250 — 12 — 12 Common stock issued for vested restricted stock units 312 — (2 ) — (2 ) Balance, September 30, 2019 5,736,242 $ 5 $ 263,108 $ (256,970 ) $ 6,143 Nine Months Ended September 30, 2019 Shares of Common Stock Common Stock Additional Paid-in Capital Accumulated Deficit Total Stockholders’ Equity Balance, December 31, 2018 4,797,198 $ 5 $ 248,938 $ (217,718 ) $ 31,225 Net loss — — — (39,252 ) (39,252 ) Stock-based compensation expense — — 1,387 — 1,387 Common stock issued through employee stock purchase plan 3,684 — 37 — 37 Common stock issued, net of expenses 768,658 — 9,761 — 9,761 Common stock issued for conversion of March 2019 Notes 162,600 — 2,984 — 2,984 Common stock issued for exercise of stock options 2,250 — 12 — 12 Common stock issued for vested restricted stock units 1,852 — (11 ) — (11 ) Balance, September 30, 2019 5,736,242 $ 5 $ 263,108 $ (256,970 ) $ 6,143
Common Stock Reserved For Future Issuances	The Company had reserved shares of common stock for future issuance as follows: September 30, 2020 December 31, 2019 Outstanding stock options 817,855 526,070 Outstanding restricted stock units 80,137 96,637 Warrants to purchase common stock associated with June 2016 Public Offering 421,867 421,867 Warrants to purchase common stock associated with March 2018 Public Offering – Series 2 798,810 798,810 Warrants to purchase common stock associated with December 2019 Public Offering 4,472,205 4,472,205 Option to purchase common stock associated with December 2019 Public Offering — 583,333 Warrants to purchase common stock associated with Solar loan agreement 12,243 12,243 For possible future issuance for the conversion of the March 2019 Notes 1,138,200 1,138,200 For possible future issuance for the conversion of the April 2020 Notes 1,622,138 — For possible future issuance under 2014 Equity Incentive Plan (Note 9) 161,776 55,478 For possible future issuance under Employee Stock Purchase Plan 5,895 7,423 For possible future issuance under 2015 Inducement Award Plan (Note 9) 14,050 31,550 Total common shares reserved for future issuance 9,545,176 8,143,816

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	The activity for the Company’s 2009 Stock Option Plan, 2014 Plan, and 2015 Plan, for the nine months ended September 30, 2020, is summarized as follows: Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value ($000) Outstanding — December 31, 2019 526,070 $ 30.55 7.62 $ 60 Granted 324,437 $ 8.39 Exercised (166 ) $ 8.60 Forfeited/Cancelled (32,486 ) $ 26.46 Outstanding — September 30, 2020 817,855 $ 21.92 7.80 $ — Exercisable — September 30, 2020 415,309 $ 33.06 6.81 $ — Vested or expected to vest — September 30, 2020 817,855 $ 21.92 7.80 $ —
Schedule of Restricted Stock Units ("RSU") Activity	Restricted stock unit (“RSU”) activity under the 2014 Plan and 2015 Plan for the nine months ended September 30, 2020, is summarized as follows: Number of Shares Weighted Average Grant Date Fair Value Per Share Non-vested at December 31, 2019 96,637 $ 14.18 Granted 25,695 $ 8.63 Vested (25,009 ) $ 14.59 Forfeited/Cancelled (17,186 ) $ 12.67 Non-vested at September 30, 2020 80,137 $ 12.60
Stock-Based Compensation Expense Related to Stock Options	Stock-based compensation expense related to stock options is included in the following line items in the accompanying unaudited condensed consolidated statements of operations (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development $ 130 $ 148 $ 394 $ 471 Selling, general and administrative 269 301 826 916 Total $ 399 $ 449 $ 1,220 $ 1,387

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured on a Recurring Basis	The following table summarizes the conclusions reached as of September 30, 2020 and December 31, 2019 for financial instruments measured at fair value on a recurring basis (in thousands): Fair Value Hierarchy Classification Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2020 Cash $ 805 $ 805 — — Restricted cash 273 273 — — Money market funds 28,689 28,689 — — Total assets $ 29,767 $ 29,767 — — Warrant liabilities $ 2,282 — — $ 2,282 Derivative liabilities 2,606 — — 2,606 Total liabilities $ 4,888 — — $ 4,888 December 31, 2019 Cash $ 23 $ 23 — — Restricted cash 273 273 — — Money market funds 41,897 41,897 — — Total assets $ 42,193 $ 42,193 — — Warrant liabilities $ 18,396 — — $ 18,396 Derivative liability 3,192 — — 3,192 Total liabilities $ 21,588 — — $ 21,588
Reconciliation of liabilities using level 3 inputs	A reconciliation of the beginning and ending balances for liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) is as follows (in thousands): Warrant Liabilities Balance – December 31, 2019 $ 18,396 Gain adjustment to fair value (16,114 ) Balance – September 30, 2020 $ 2,282 Derivative Liabilities Balance – December 31, 2019 $ 3,192 Bifurcated embedded conversion option associated with April 2020 Notes 8,110 Adjustment for partial conversion of April 2020 Notes (1,612 ) Gain adjustment to fair value (7,084 ) Balance – September 30, 2020 $ 2,606

Description of Business and B_2

Description of Business and Basis of Preparation - Additional Information (Detail)	Oct. 01, 2020USD ($)shares	Jul. 17, 2020shares	Jul. 16, 2020shares	Apr. 10, 2020USD ($)shares	Apr. 09, 2020USD ($)	Dec. 12, 2019USD ($)$ / sharesshares	Sep. 30, 2020USD ($)shares	Sep. 30, 2019USD ($)shares	Sep. 30, 2020USD ($)shares	Sep. 30, 2019USD ($)shares	Jun. 30, 2020shares	Dec. 31, 2019USD ($)shares	Jun. 30, 2019shares	Dec. 31, 2018shares
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Accumulated deficit							$ (283,902,000)		$ (283,902,000)			$ (271,428,000)
Cash and cash equivalents							29,494,000		29,494,000			$ 41,920,000
Shelf registration maximum equity offering price									322,800,000
Common stock issued, net of expenses							$ 1,909,000	$ 3,206,000	$ 4,578,000	$ 9,761,000
Reverse stock split, ratio			0.1
Common stock, shares authorized (in shares) | shares		100,000,000	250,000,000				100,000,000		100,000,000			100,000,000
Common stock, shares issued (in shares) | shares		10,508,302	105,083,291				10,798,119		10,798,119			9,741,372
Common stock, shares outstanding (in shares) | shares		10,508,302	105,083,291				10,798,119		10,798,119			9,741,372
Stock issued during period as result of reverse stock splits | shares		0	0
New Jersey Technology Business Tax Certificate Transfer (NOL) Program
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Maximum selling value of unused net operating losses and research and development tax credit to profitable tax payers.									$ 15,000,000
Income tax benefit from sale of unused net operating losses and research and development tax credit									3,100,000
Amount received from the program									$ 9,900,000
Option to Purchase Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Options expiration date						2020-01
Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Common stock issued, net of expenses (in shares) | shares							315,939	279,911	647,504	768,658
Common stock issued, net of expenses							$ 0	$ 0	$ 0	$ 0
Common stock, shares outstanding (in shares) | shares							10,798,119	5,736,242	10,798,119	5,736,242	10,478,927	9,741,372	5,452,011	4,797,198
December 2019 Public Offering
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Common stock issued, net of expenses (in shares) | shares						3,888,888
Number of warrants issued to purchase common stock (in shares) | shares						3,888,888
Share price (in dollars per share) | $ / shares						$ 9
Common stock issued, net of expenses						$ 32,500,000
Underwriters | Warrant liability
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of warrants issued to purchase common stock (in shares) | shares						583,333
Number of warrants exercised | shares						583,333
October 2020 Shelf Registration
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shelf registration maximum equity offering price									$ 200,000,000
Subsequent Event | October 2020 Shelf Registration
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shelf registration maximum equity initial offering price	$ 200,000,000
Shelf registration maximum equity offering price	200,000,000
Subsequent Event | October 2020 Shelf Registration | Sales Agreement | Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shelf registration maximum equity offering price	$ 50,000,000
Number of Shelf Registration Equity Sold | shares	0
Maximum | Option to Purchase Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of options not exercised | shares						583,333
Maximum | Underwriters
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Option to purchase shares of common stock | shares						583,333
April 2020 Note Purchase Agreement | 6.0% Senior Convertible Notes due 2026
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Date of issuance and sale of notes					Apr. 9, 2020
Face amount					$ 10,000,000
Interest rate					6.00%
Aspire Capital | Common Stock Purchase Agreement
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Sale of common stock at sole discretion				$ 20,000,000
Number of purchase aggregate shares of common stock | shares				1,956,547
Percentage of common stock outstanding				19.99%
Common stock issued, net of expenses (in shares) | shares							125,000		125,000
Aspire Capital | Common Stock Purchase Agreement | Maximum
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Sale of common stock at sole discretion				$ 20,000,000
Percentage of common stock outstanding				19.99%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Schedule of Diluted Net Loss Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounting Policies [Abstract]
Net income (loss)	$ 909	$ (7,941)	$ (12,474)	$ (39,252)
Dilutive effect of convertible debt	(4,649)	(1,815)	(2,917)	0
Net loss allocated to common shares	$ (3,740)	$ (9,756)	$ (15,391)	$ (39,252)
Weighted average common shares outstanding – basic	10,627,618	5,569,739	10,129,098	5,278,757
Dilutive effect of stock options and restricted stock units	1,058	0	0	0
Dilutive effect of convertible debt	2,760,338	1,138,200	1,091,704	0
Weighted average common shares outstanding – diluted	13,389,014	6,707,939	11,220,802	5,278,757
Net loss per share – diluted	$ (0.28)	$ (1.45)	$ (1.37)	$ (7.44)

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Shares (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	6,594,117	1,848,552	7,741,317	2,986,752
Warrant liability
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	4,472,205	0	4,472,205	0
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	808,855	518,870	817,855	518,870
Outstanding restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	80,137	96,762	80,137	96,762
Warrants to purchase common stock associated with Solar loan agreement | Warrant liability
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	12,243	12,243	12,243	12,243
Warrants to purchase common stock associated with June 2016 Public Offering | Warrant liability
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	421,867	421,867	421,867	421,867
March 2018 Public Offering Series 2 [Member] | Warrant liability
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	798,810	798,810	798,810	798,810
Common stock associated with March 2019 Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	0	1,138,200	1,138,200

Short-term Investments (Details

Short-term Investments (Details) $ in Thousands	Dec. 31, 2019USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 6,494
Unrealized Gains	15
Unrealized Losses	(14)
Fair Value	6,495
Commercial paper
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	998
Unrealized Gains	0
Unrealized Losses	0
Fair Value	998
Overnight repurchase agreement
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	3,500
Unrealized Gains	0
Unrealized Losses	0
Fair Value	3,500
U.S. government securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1,996
Unrealized Gains	15
Unrealized Losses	(14)
Fair Value	$ 1,997

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid research and development services	$ 1,656	$ 3,043
Prepaid insurance	610	252
Other prepaid expenses	54	19
Other current assets	442	674
Total prepaid expenses and other current assets	$ 2,762	$ 3,988

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued research and development expenses	$ 915	$ 1,296
Accrued employee bonus compensation	1,152	1,798
Other accrued expenses	937	707
Total accrued expenses	$ 3,004	$ 3,801

Borrowings - Additional Informa

Borrowings - Additional Information (Details)	Apr. 09, 2020USD ($)d$ / shares	Mar. 07, 2019USD ($)d$ / shares	Sep. 30, 2016USD ($)	Jun. 30, 2020USD ($)shares	Apr. 30, 2019USD ($)shares	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Apr. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Payment of debt issuance costs									$ 494,000	$ 1,253,000
Convertible debt and derivative liability						$ 13,275,000			13,275,000			$ 11,522,000
Amortization of debt issuance costs and discount						311,000	$ 306,000		910,000	879,000
Loss on extinguishment of debt						0	0		$ 806,000	1,045,000
April 2020 Note Purchase Agreement
Debt Instrument [Line Items]
Date of issuance and sale of notes	Apr. 9, 2020
Face amount	$ 10,000,000
Proceeds from debt, net of issuance costs	9,500,000
Payment of debt issuance costs	$ 500,000
Purchase price as percentage of principal amount	100.00%
Interest rate	6.00%
Payment terms									The April 2020 Notes will bear interest at a rate of 6.0% per annum, payable semiannually in arrears on April 15 and October 15 of each year, beginning October 15, 2020. The April 2020 Notes will mature on April 15, 2026, unless earlier converted, redeemed or repurchased.
Notes maturity date	Apr. 15, 2026
Notes maturity description									The April 2020 Notes will mature on April 15, 2026, unless earlier converted, redeemed or repurchased
Senior convertible notes						1,500,000			$ 1,500,000
Unamortized debt issuance cost						100,000			100,000
Bifurcated embedded conversion option derivative liability						2,000,000			2,000,000
Derivative, fair value						8,100,000			8,100,000
Debt issuance costs						400,000			400,000
Gain (loss) on fair value adjustment of derivative liability						3,200,000			4,500,000
Amortization of debt issuance costs and discount						100,000			100,000
Conversion of convertible note, amount				$ 2,000,000
Conversion of convertible note exchanged for shares | shares				316,461
Loss on extinguishment of debt				$ 800,000
Fair value of convertible debt and derivative liability						7,100,000			$ 7,100,000		$ 2,000,000
Fair value of the consideration issued				$ 2,800,000
Conversion terms									holders of the April 2020 Notes may convert their April 2020 Notes at their option at any time prior to the close of business on the business day immediately preceding April 15, 2026 into shares of the Company’s common stock.
Conversion rate, number of shares to be issued per $1000 of principal (in shares)	111.1108
Principal amount of notes used as the denominator for conversion into notes	$ 1,000
Initial conversion price of notes | $ / shares	$ 9
Conversion rate, number of shares to be issued per $1000 of principal (in shares) after adjustment to certain events	1,938,600
Convertible notes, redemption start date	Apr. 15, 2023
Convertible notes, threshold percentage of stock price trigger	130.00%
Convertible notes, threshold trading days | d	20
Convertible notes, threshold consecutive trading days | d	30
Redemption price as percentage of the principal amount	100.00%
Redemption price as percentage of the principal amount subject to certain exceptions	100.00%
Senior Convertible Note Purchase Agreement
Debt Instrument [Line Items]
Date of issuance and sale of notes		Mar. 7, 2019
Face amount		$ 16,000,000
Proceeds from debt, net of issuance costs		14,700,000
Payment of debt issuance costs		$ 1,300,000
Purchase price as percentage of principal amount		100.00%
Interest rate		6.00%
Payment terms									The March 2019 Notes bear interest at a rate of 6.0% per annum payable semiannually in arrears on March 15 and September 15 of each year, beginning September 15, 2019. The March 2019 Notes will mature on March 15, 2025, unless earlier converted, redeemed or repurchased.
Notes maturity date		Mar. 15, 2025
Notes maturity description									The March 2019 Notes will mature on March 15, 2025, unless earlier converted, redeemed or repurchased
Senior convertible notes						9,100,000			$ 9,100,000
Unamortized debt issuance cost						400,000			400,000
Bifurcated embedded conversion option derivative liability						600,000			600,000
Derivative, fair value						7,000,000			7,000,000
Debt issuance costs								$ 600,000
Gain (loss) on fair value adjustment of derivative liability						2,100,000	2,300,000		2,600,000	200,000
Amortization of debt issuance costs and discount						300,000	$ 300,000		800,000	$ 800,000
Conversion of convertible note, amount					$ 2,000,000
Conversion of convertible note exchanged for shares | shares					162,600
Loss on extinguishment of debt					$ 200,000			800,000
Fair value of convertible debt and derivative liability					2,800,000	$ 10,100,000			$ 10,100,000
Fair value of the consideration issued					$ 3,000,000
Conversion terms									holder of the March 2019 Notes may convert their March 2019 Notes at their option at any time prior to the close of business on the business day immediately preceding March 15, 2025 into shares of the Company’s common stock.
Conversion rate, number of shares to be issued per $1000 of principal (in shares)		73.9096
Principal amount of notes used as the denominator for conversion into notes		$ 1,000
Initial conversion price of notes | $ / shares		$ 13.53
Conversion rate, number of shares to be issued per $1000 of principal (in shares) after adjustment to certain events		81
Convertible notes, redemption start date		Mar. 15, 2022
Convertible notes, threshold percentage of stock price trigger		130.00%
Convertible notes, threshold trading days | d		20
Convertible notes, threshold consecutive trading days | d		30
Redemption price as percentage of the principal amount		100.00%
Redemption price as percentage of the principal amount subject to certain exceptions		100.00%
Reacquisition price of outstanding debt								15,900,000
Carrying value of debt obligation								$ 15,100,000
Principal amount of notes used as the denominator for conversion into notes after adjustment of certain events		$ 1,000
Term Loan | Secured Debt
Debt Instrument [Line Items]
Face amount			$ 15,000,000
Loan agreement term			48 months
Term Loan | Secured Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			8.49%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	Mar. 01, 2018USD ($)ft²	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)
Commitment And Contingencies [Line Items]
Long-term lease agreement, area of office space | ft²	19,275
Lease term	11 years
Total lease payments	$ 7,300,000	$ 114,000	$ 336,000
Lessee, operating lease, existence of option to extend	true
Renewal term	5 years
Renewal term, description	The Company has the option to renew for two consecutive five-year periods from the end of the first term and the Company is not reasonably certain that the option to renew the Lease will be exercised. Under the Lease, the Company furnished a security deposit in the form of a standby letter of credit in the amount of $0.3 million, which was reduced by fifty-five thousand dollars on the first anniversary of the commencement date.  The security deposit will continue to be reduced by fifty-five thousand dollars every two years on the commencement date anniversary for eight years.
Security deposit in the form of a standby letter of credit	$ 300,000
Decrease in security deposit	$ 55,000
Maximum
Commitment And Contingencies [Line Items]
Milestone payments from the Company			$ 19,000,000

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Quantitative Information Associated with Amounts Recognized in Unaudited Condensed Consolidated Financial Statements for Lease (Detail) - USD ($) $ in Thousands	Mar. 01, 2018	Sep. 30, 2020	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Operating lease cost		$ 166	$ 498
Variable lease cost		9	36
Total operating lease expense		175	534
Total lease payments	$ 7,300	$ 114	$ 336
Remaining Lease term (years)		8 years 10 months 2 days	8 years 10 months 2 days
Discount rate		15.00%	15.00%

Commitments and Contingencies_3

Commitments and Contingencies - Future Minimum Lease Payments (Detail) $ in Thousands	Sep. 30, 2020USD ($)
Commitments And Contingencies Disclosure [Abstract]
2020	$ 170
2021	517
2022	527
2023	715
2024	730
Thereafter	3,533
Total	$ 6,192

Commitments and Contingencies_4

Commitments and Contingencies - Presentation of Operating Lease Liability and Right-of-Use Asset (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Present value of future minimum lease payments	$ 3,379
Operating lease liability, current portion	47	$ 36
Operating lease liability, long-term portion	3,332	3,326
Total operating lease liability	3,379
Difference between future minimum lease payments and discounted cash flows	2,813
Operating lease right-of-use asset	$ 3,047	$ 3,191

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands	Jul. 17, 2020shares	Jul. 16, 2020shares	Apr. 10, 2020USD ($)TradingDay$ / sharesshares	Sep. 30, 2016$ / sharesshares	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2019USD ($)	Dec. 31, 2019$ / sharesshares
Schedule Of Capitalization Equity [Line Items]
Common stock, par value (in dollars per share) | $ / shares					$ 0.001		$ 0.001		$ 0.001
Common stock, shares authorized (in shares)	100,000,000	250,000,000			100,000,000		100,000,000		100,000,000
Common stock, shares issued (in shares)	10,508,302	105,083,291			10,798,119		10,798,119		9,741,372
Common stock, shares outstanding (in shares)	10,508,302	105,083,291			10,798,119		10,798,119		9,741,372
Common stock, reverse stock split							1-for-10
Common stock, reverse stock split ratio		0.1
Number of fractional shares issued result of reverse stock split	0	0
Proceeds from common stock issued | $							$ 4,702	$ 10,069
Derivative liability fair value adjustment | $					$ 5,290	$ 2,324	6,683	223
Warrant liabilities fair value adjustment | $					(7,786)	(1,830)	(16,114)	2,643
Warrant liabilities | $					2,300		2,300
Warrants to purchase common stock associated with Loan Agreement
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)				12,243
Exercise price of warrants (in dollars per share) | $ / shares				$ 36.754
Warrant expiration period				5 years
Other (Income) Expense | Senior Convertible Note Purchase Agreement
Schedule Of Capitalization Equity [Line Items]
Derivative liability fair value adjustment | $					$ 5,300	$ 2,300	$ 6,700	$ 200
Aspire Capital | Common Stock Purchase Agreement
Schedule Of Capitalization Equity [Line Items]
Sale of common stock at sole discretion | $			$ 20,000
Number of purchase aggregate shares of common stock			1,956,547
Percentage of common stock outstanding			19.99%
Number of shares committed			70,910
Average purchase price of shares sold | $ / shares			$ 8.461
Percentage of common stock owned			19.99%
Common stock issued, net of expenses (in shares)					125,000		125,000
Proceeds from common stock issued | $					$ 600		$ 600
Sale of common stock maximum number of share sold per business day			25,000
Stock purchase price average number of trading days lowest closing sales price out of consecutive trading days | TradingDay			3
Stock purchase price number of consecutive trading days | TradingDay			10
Increase in sale of common stock maximum number of share sold per business day			200,000
Percentage of purchase price per share			97.00%
Aspire Capital | Common Stock Purchase Agreement | Commitment Shares
Schedule Of Capitalization Equity [Line Items]
Common stock shares issued			70,910
Aspire Capital | Common Stock Purchase Agreement | Commitment Shares | Other Expense
Schedule Of Capitalization Equity [Line Items]
Fair value of shares | $							$ 600
Aspire Capital | Common Stock Purchase Agreement | Maximum
Schedule Of Capitalization Equity [Line Items]
Sale of common stock at sole discretion | $			$ 20,000
Percentage of common stock outstanding			19.99%
Stock purchase percentage on aggregate shares of common stock traded			30.00%
Closing sale price of common stock | $ / shares			$ 0.25

Stockholder's Equity - Summary

Stockholder's Equity - Summary of Common Stock Shares Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Common Stock Outstanding Roll Forward [Roll Forward]
Beginning balance	$ 6,333	$ 10,402	$ 12,895	$ 31,225
Beginning balance (in shares)			9,741,372
Net income (loss)	909	(7,941)	$ (12,474)	(39,252)
Stock-based compensation expense	399	449	1,220	1,387
Common stock issued through employee stock purchase and stock option plans			28
Common stock issued, net of expenses	1,909	3,206	$ 4,578	9,761
Common stock issued through employee stock purchase plan	9	17		37
Common stock issued for exercise of stock options		12		12
Common stock issued for exercise of stock options (in shares)			166
Common stock issued for Commitment Shares			$ 602
Common stock issued for vested restricted stock units	(1)	(2)	(75)	(11)
Ending balance	$ 9,558	6,143	$ 9,558	6,143
Ending balance (in shares)	10,798,119		10,798,119
April 2020 Notes
Common Stock Outstanding Roll Forward [Roll Forward]
Common stock issued for conversion of Notes			$ 2,784
March 2019 Notes
Common Stock Outstanding Roll Forward [Roll Forward]
Common stock issued for conversion of Notes				2,984
Common Stock
Common Stock Outstanding Roll Forward [Roll Forward]
Beginning balance	$ 10	$ 5	$ 10	$ 5
Beginning balance (in shares)	10,478,927	5,452,011	9,741,372	4,797,198
Net income (loss)	$ 0	$ 0	$ 0	$ 0
Stock-based compensation expense	0	0	0	0
Common stock issued through employee stock purchase and stock option plans			$ 0
Common stock issued through employee stock purchase and stock option plans (in shares)			4,652
Common stock issued, net of expenses	$ 0	$ 0	$ 0	$ 0
Common stock issued, net of expenses (in shares)	315,939	279,911	647,504	768,658
Common stock issued through employee stock purchase plan	$ 0	$ 0		$ 0
Common stock issued through employee stock purchase plan (in shares)	2,284	1,758		3,684
Common stock issued for exercise of stock options		$ 0		$ 0
Common stock issued for exercise of stock options (in shares)		2,250		2,250
Common stock issued for Commitment Shares			$ 0
Common stock issued for Commitment Shares (in shares)			70,910
Common stock issued for vested restricted stock units	$ 0	$ 0	$ 0	$ 0
Common stock issued for vested restricted stock units (in shares)	969	312	17,220	1,852
Ending balance	$ 10	$ 5	$ 10	$ 5
Ending balance (in shares)	10,798,119	5,736,242	10,798,119	5,736,242
Common Stock | April 2020 Notes
Common Stock Outstanding Roll Forward [Roll Forward]
Common stock issued for conversion of Notes			$ 0
Common stock issued for conversion of Notes (in shares)			316,461
Common Stock | March 2019 Notes
Common Stock Outstanding Roll Forward [Roll Forward]
Common stock issued for conversion of Notes				$ 0
Common stock issued for conversion of Notes (in shares)				162,600
Additional Paid-in Capital
Common Stock Outstanding Roll Forward [Roll Forward]
Beginning balance	$ 291,134	$ 259,426	$ 284,313	$ 248,938
Net income (loss)	0	0	0	0
Stock-based compensation expense	399	449	1,220	1,387
Common stock issued through employee stock purchase and stock option plans			28
Common stock issued, net of expenses	1,909	3,206	4,578	9,761
Common stock issued through employee stock purchase plan	9	17		37
Common stock issued for exercise of stock options		12		12
Common stock issued for Commitment Shares			602
Common stock issued for vested restricted stock units	(1)	(2)	(75)	(11)
Ending balance	293,450	263,108	293,450	263,108
Additional Paid-in Capital | April 2020 Notes
Common Stock Outstanding Roll Forward [Roll Forward]
Common stock issued for conversion of Notes			2,784
Additional Paid-in Capital | March 2019 Notes
Common Stock Outstanding Roll Forward [Roll Forward]
Common stock issued for conversion of Notes				2,984
Accumulated Deficit
Common Stock Outstanding Roll Forward [Roll Forward]
Beginning balance	(284,811)	(249,029)	(271,428)	(217,718)
Net income (loss)	909	(7,941)	(12,474)	(39,252)
Stock-based compensation expense	0	0	0	0
Common stock issued through employee stock purchase and stock option plans			0
Common stock issued, net of expenses	0	0	0	0
Common stock issued through employee stock purchase plan	0	0		0
Common stock issued for exercise of stock options		0		0
Common stock issued for Commitment Shares			0
Common stock issued for vested restricted stock units	0	0	0	0
Ending balance	$ (283,902)	$ (256,970)	(283,902)	(256,970)
Accumulated Deficit | April 2020 Notes
Common Stock Outstanding Roll Forward [Roll Forward]
Common stock issued for conversion of Notes			$ 0
Accumulated Deficit | March 2019 Notes
Common Stock Outstanding Roll Forward [Roll Forward]
Common stock issued for conversion of Notes				$ 0

Stockholder's Equity - Schedule

Stockholder's Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Detail) - shares	Sep. 30, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Common shares reserved for future issuance	9,545,176	8,143,816
March 2019 Notes
Class of Stock [Line Items]
Common shares reserved for future issuance	1,138,200	1,138,200
April 2020 Notes
Class of Stock [Line Items]
Common shares reserved for future issuance	1,622,138	0
2014 Equity Incentive Plan
Class of Stock [Line Items]
Common shares reserved for future issuance	161,776	55,478
2014 Employee Stock Purchase Plan
Class of Stock [Line Items]
Common shares reserved for future issuance	5,895	7,423
2015 Inducement Award Plan
Class of Stock [Line Items]
Common shares reserved for future issuance	14,050	31,550
June 2016 Public Offering | Warrant liability
Class of Stock [Line Items]
Common shares reserved for future issuance	421,867	421,867
March 2018 Public Offering | Series 1 Warrant
Class of Stock [Line Items]
Common shares reserved for future issuance	798,810	798,810
December 2019 Public Offering | Warrant liability
Class of Stock [Line Items]
Common shares reserved for future issuance	4,472,205	4,472,205
December 2019 Public Offering | Option to Purchase Common Stock
Class of Stock [Line Items]
Common shares reserved for future issuance	0	583,333
Warrants to purchase common stock associated with Solar loan agreement | Warrant liability
Class of Stock [Line Items]
Common shares reserved for future issuance	12,243	12,243
Stock options
Class of Stock [Line Items]
Common shares reserved for future issuance	817,855	526,070
Restricted Stock Units
Class of Stock [Line Items]
Common shares reserved for future issuance	80,137	96,637

Stock-based Compensation - 2014

Stock-based Compensation - 2014 Equity Incentive Plan (Details) - 2014 Equity Incentive Plan - shares	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of additional shares authorized	389,654	191,887
Possible future issuance under equity compensation plan (in shares)	161,776

Stock-based Compensation - 2015

Stock-based Compensation - 2015 Inducement Award Plan (Details) - shares	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (shares)	324,437
2015 Inducement Award Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Possible future issuance under equity compensation plan (in shares)	14,050
Granted (shares)	17,500	11,500

Stock-based Compensation - Stoc

Stock-based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Number of Shares
Beginning balance - Outstanding (shares)	526,070
Granted (shares)	324,437
Exercised (shares)	(166)
Forfeited/Cancelled(shares)	(32,486)
Ending balance - Outstanding (shares)	817,855	526,070
Exercisable (shares)	415,309
Vested or expected to vest (shares)	817,855
Weighted- Average Exercise Price
Beginning balance - Outstanding (in dollars per share)	$ 30.55
Granted (in dollars per share)	8.39
Exercised (in dollars per share)	8.60
Forfeited/Cancelled (in dollars per share)	26.46
Ending balance - Outstanding (in dollars per share)	21.92	$ 30.55
Exercisable (in dollars per share)	33.06
Vested or expected to vest (in dollars per share)	$ 21.92
Weighted- Average Remaining Contractual Life (in years)
Balance - Outstanding	7 years 9 months 18 days	7 years 7 months 13 days
Exercisable	6 years 9 months 21 days
Vested or expected to vest	7 years 9 months 18 days
Aggregate Intrinsic Value ($000)
Balance - Outstanding	$ 0	$ 60
Exercisable	0
Vested and expected to vest	$ 0

Stock-based Compensation - Sche

Stock-based Compensation - Schedule of Restricted Stock Units ("RSU") Activity (Details) - Restricted Stock Units	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Number of Shares
Beginning balance - Outstanding (shares) | shares	96,637
Options granted in period (shares) | shares	25,695
Vested (shares) | shares	(25,009)
Forfeited/Cancelled (shares) | shares	(17,186)
Ending balance - Outstanding (shares) | shares	80,137
Weighted Average Grant Date Fair Value Per Share
Beginning balance - Outstanding (in dollars per share) | $ / shares	$ 14.18
Granted (in dollars per share) | $ / shares	8.63
Vested (in dollars per share) | $ / shares	14.59
Forfeited/Cancelled dollars per share) | $ / shares	12.67
Ending balance - Outstanding (in dollars per share) | $ / shares	$ 12.60
Vesting percentage	25.00%
Vesting period of options	4 years

Stock-based Compensation - Comp

Stock-based Compensation - Compensation Cost (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based compensation expense	$ 399,000	$ 449,000	$ 1,220,000	$ 1,387,000
Tax benefit from compensation expense	$ 0	$ 0	$ 0	$ 0

Stock-based Compensation - Expe

Stock-based Compensation - Expense Related to Stock Options (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to stock options	$ 399	$ 449	$ 1,220	$ 1,387
Research and development, net
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to stock options	130	148	394	471
Selling, general and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to stock options	$ 269	$ 301	$ 826	$ 916

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Measured on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	$ 29,767	$ 42,193
Fair value of financial liabilities	4,888	21,588
Warrant liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	2,282	18,396
Derivative liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	2,606	3,192
Cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	805	23
Restricted cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	273	273
Money market funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	28,689	41,897
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	29,767	42,193
Fair value of financial liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Warrant liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	805	23
Quoted Prices in Active Markets for Identical Assets (Level 1) | Restricted cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	273	273
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	28,689	41,897
Significant Other Observable Inputs (Level 2)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	0	0
Fair value of financial liabilities	0	0
Significant Other Observable Inputs (Level 2) | Warrant liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	0	0
Significant Other Observable Inputs (Level 2) | Derivative liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	0	0
Significant Other Observable Inputs (Level 2) | Cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	0	0
Significant Other Observable Inputs (Level 2) | Restricted cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	0	0
Significant Other Observable Inputs (Level 2) | Money market funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	0	0
Significant Unobservable Inputs (Level 3)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	0	0
Fair value of financial liabilities	4,888	21,588
Significant Unobservable Inputs (Level 3) | Warrant liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	2,282	18,396
Significant Unobservable Inputs (Level 3) | Derivative liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	2,606	3,192
Significant Unobservable Inputs (Level 3) | Cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	0	0
Significant Unobservable Inputs (Level 3) | Restricted cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	0	0
Significant Unobservable Inputs (Level 3) | Money market funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - Level 3	Sep. 30, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrant liabilities, maturity date	Jun. 12, 2023
Stock Price Volatility
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative liabilities, unobservable inputs rate	55.5
Stock Price Volatility | Minimum [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrant liabilities, stock price volatility rate	69.1
Derivative liabilities, unobservable inputs rate	54.4
Stock Price Volatility | Maximum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrant liabilities, stock price volatility rate	75.7
Derivative liabilities, unobservable inputs rate	59.4
Stock Price Volatility | Weighted Average
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrant liabilities, stock price volatility rate	71.1
Weighted Average Expected Term
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrant liabilities, expected term	2 years
Weighted Average Expected Term | Minimum [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrant liabilities, expected term		1 year 1 month 28 days
Weighted Average Expected Term | Maximum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrant liabilities, expected term		2 years 8 months 12 days
Market Credit Spread
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative liabilities, unobservable inputs rate	1,606
Estimated Yield
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative liabilities, unobservable inputs rate	16.4
Discounts for Lack of Marketability | March 2019 Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Senior convertible notes, unobservable inputs rate	5.60

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Reconciliation of Beginning and Ending Balances for Liabilities Measured at Fair Value on Recurring Basis (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Warrant liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 18,396
Gain adjustment to fair value	(16,114)
Ending balance	2,282
Derivative liabilities
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	3,192
Bifurcated embedded conversion option associated with April 2020 Notes	8,110
Adjustment for partial conversion of April 2020 Notes	(1,612)
Gain adjustment to fair value	(7,084)
Ending balance	$ 2,606