SCYNEXIS (SCYX) 10-K 14 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Mar. 01, 2019	Jun. 30, 2018
Document And Entity Information [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 Shell Company	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		50,148,458
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 75,725,929

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 11,439	$ 11,469
Short-term investments	32,718	32,424
Prepaid expenses and other current assets	7,251	1,067
Restricted cash	55	0
Total current assets	51,463	44,960
Other assets	812	572
Deferred offering costs	106	314
Restricted cash	273	0
Property and equipment	516	4
Total assets	53,170	45,850
Current liabilities:
Accounts payable	3,653	3,833
Accrued expenses	2,103	1,705
Deferred revenue, current portion	121	257
Loan payable, current portion	0	4,349
Total current liabilities	5,877	10,144
Deferred revenue, non-current	0	121
Warrant liabilities	986	3,872
Loan payable expected to be refinanced (see Note 7)	15,082	10,303
Total liabilities	21,945	24,440
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value, authorized 5,000,000 shares as of December 31, 2018 and December 31, 2017; 0 shares issued and outstanding as of December 31, 2018 and December 31, 2017	0	0
Common stock, $0.001 par value, authorized 125,000,000 shares as of December 31, 2018 and December 31, 2017; 47,971,989 and 28,971,651 shares issued and outstanding as of December 31, 2018, and December 31, 2017, respectively	48	29
Additional paid-in capital	248,895	226,631
Accumulated deficit	(217,718)	(205,250)
Total stockholders’ equity	31,225	21,410
Total liabilities and stockholders’ equity	$ 53,170	$ 45,850

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017	May 07, 2014
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	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)	125,000,000	125,000,000
Common stock, shares issued (in shares)	47,971,989	28,971,651
Common stock, shares outstanding (in shares)	47,971,989	28,971,651

Statements of Operations

Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenue	$ 257	$ 257
Operating expenses:
Research and development, net	21,560	18,326
Selling, general and administrative	8,680	8,251
Total operating expenses	30,240	26,577
Loss from operations	(29,983)	(26,320)
Other expense (income):
Amortization of debt discount	428	400
Interest income	(967)	(386)
Interest expense	1,626	1,455
Warrant liabilities fair value adjustment	(11,866)	(2,729)
Total other income:	(10,779)	(1,260)
Loss before taxes	(19,204)	(25,060)
Income tax benefit	6,736	0
Net loss	$ (12,468)	$ (25,060)
Net loss per share – basic and diluted	$ (0.28)	$ (0.94)
Weighted average common shares outstanding – basic and diluted	43,883,995	26,746,322

Statements of Changes in Stockh

Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2016	$ 34,819	$ 24	$ 214,918	$ (180,123)
Beginning balance (in shares) at Dec. 31, 2016		24,609,411
Cumulative stock-based compensation forfeiture adjustment			67	(67)
Net loss	(25,060)			(25,060)
Stock-based compensation expense	1,662		1,662
Common stock issued through employee stock purchase plan	35		35
Common stock issued through employee stock purchase plan (in shares)		18,132
Common stock issued, net of expenses	9,954	$ 5	9,949
Common stock issued, net of expenses (in shares)		4,344,108
Ending balance at Dec. 31, 2017	$ 21,410	$ 29	226,631	(205,250)
Ending balance (in shares) at Dec. 31, 2017	28,971,651	28,971,651
Net loss	$ (12,468)			(12,468)
Stock-based compensation expense	1,816		1,816
Common stock issued through employee stock purchase plan	39		39
Common stock issued through employee stock purchase plan (in shares)		31,361
Common stock issued, net of expenses	20,437	$ 19	20,418
Common stock issued, net of expenses (in shares)		18,959,675
Common stock issued for vested restricted stock units	(9)		(9)
Common stock issued for vested restricted stock units (in shares)		9,302
Ending balance at Dec. 31, 2018	$ 31,225	$ 48	$ 248,895	$ (217,718)
Ending balance (in shares) at Dec. 31, 2018	47,971,989	47,971,989

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (12,468)	$ (25,060)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	53	41
Stock-based compensation expense	1,816	1,662
(Accretion)/amortization of investment discount/premium	(111)	124
Amortization of debt discount	428	400
Change in fair value of warrant liabilities	(11,866)	(2,729)
Changes in deferred rent	(4)	(25)
Deferred offering write-off	230	0
Changes in operating assets and liabilities:
Prepaid expenses, other assets, and deferred costs	(6,367)	(790)
Accounts payable and accrued expenses	223	2,078
Deferred revenue	(257)	(257)
Net cash used in operating activities	(28,323)	(24,556)
Cash flows from investing activities:
Maturities of investments	84,874	68,819
Purchases of property and equipment	(565)	(2)
Purchase of investments	(85,112)	(78,437)
Net cash used in investing activities	(803)	(9,620)
Cash flows from financing activities:
Proceeds from common stock issued	31,657	10,287
Payments of offering costs and underwriting discounts and commissions	(2,272)	(333)
Proceeds from employee stock purchase plan issuances	39	35
Net cash provided by financing activities	29,424	9,989
Net increase (decrease) in cash, cash equivalents, and restricted cash	298	(24,187)
Cash, cash equivalents, and restricted cash at beginning of period	11,469	35,656
Cash, cash equivalents, and restricted cash at end of period	11,767	11,469
Supplemental cash flow information:
Cash paid for interest	1,618	1,455
Cash received for interest	986	513
Noncash financing and investing activities:
Deferred offering costs reclassified to additional paid-in capital	$ 84	$ 31

Description of Business and Bas

Description of Business and Basis of Preparation	12 Months Ended
	Dec. 31, 2018
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, committed to positively impacting the lives of patients suffering from difficult-to-treat and often life-threatening infections by delivering innovative therapies. The Company is developing its lead product candidate, ibrexafungerp, as the first representative of a novel oral and intravenous triterpenoid antifungal family for the treatment of several fungal infections, including serious and life-threatening invasive fungal infections. The Company has incurred losses and negative cash flows from operations since its initial public offering ("IPO") in May 2014 and expects to continue to incur losses. The Company's liquidity over the next 12 months could be materially affected by, among other things: its ability to raise capital through equity offerings, debt financings, other non-dilutive third-party funding (e.g., grants), strategic alliances and licensing or collaboration arrangements; key ibrexafungerp development and regulatory events; costs related to its development of ibrexafungerp; and other factors. Shelf Registration Filing On August 31, 2018, the Company filed a shelf registration statement on Form S-3 (File No. 333-227167) with the SEC, which was declared effective on September 14, 2018 (the “Shelf Registration”). The Shelf Registration contained three prospectuses: • a base prospectus which covers the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $175.0 million of the Company's common stock, preferred stock, debt securities and warrants, including common stock or preferred stock issuable upon conversion of debt securities, common stock issuable upon conversion of preferred stock, or common stock, preferred stock or debt securities issuable upon the exercise of warrants; • a prospectus covering the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $25.0 million of the Company's common stock that may be issued and sold under a Controlled Equity Offering Sales Agreement SM • a warrant prospectus covering the offering, issuance, and sale of the Company’s common stock issuable upon the exercise of warrants, consisting of (i) warrants to purchase 4,218,750 shares of the Company’s common stock at an exercise price of $3.00 per share originally issued by the Company on June 24, 2016, (ii) warrants to purchase 13,198,075 shares of the Company’s common stock at an exercise price of $1.85 per share originally issued by the Company on March 8, 2018, and (iii) warrants to purchase 7,988,175 shares of the Company’s common stock at an exercise price of $2.00 per share originally issued by the Company on March 8, 2018. Upon exercise of the warrants for cash, the holders of the warrants would pay the Company the exercise price per share of common stock, or an aggregate of approximately $53.0 million if the warrants are exercised in full for cash. See Note 9 for further details. The common stock that may be offered, issued and sold by the Company under the Sales Agreement is included in the $175.0 million of securities that may be offered, issued and sold by the Company under the base prospectus. Upon termination of the Sales Agreement with Cantor, any portion of the $25.0 million included in the Sales Agreement that is not sold pursuant to the Sales Agreement will be available for sale in other offerings pursuant to the base prospectus and a corresponding prospectus supplement. March 2018 Public Offering On March 8, 2018, 17,751,500 Use of Estimates The preparation of financial statements in conformity with U.S. 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 period. Actual results could differ from those estimates. Significant estimates include: determination of the fair value of stock-based compensation grants; the estimate of services and effort expended by third-party research and development service providers used to recognize research and development expense; and the estimates and assumptions utilized in measuring the warrant liabilities fair value each reporting period.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Concentration of Credit Risk Financial instruments, which potentially expose the Company to concentrations of credit risk, consist principally of cash on deposit, cash equivalents, and short-term investments. The Company's money market fund investment (recognized as cash and cash equivalents) and short-term investments are with what the Company believes to be high quality issuers. The Company has not experienced any significant losses in such accounts. Revenue recognized from a non-refundable upfront payment from R-Pharm, CJSC (“R-Pharm”), a collaboration partner, accounted for 100% of the Company's revenue for the years ended December 31, 2018 and 2017. No other parties contributed to the Company's revenue in 2018 and 2017. Cash and Cash Equivalents The Company considers any highly liquid investments with a remaining maturity of three months or less when purchased to be cash and cash equivalents. The Company reported cash, cash equivalents, and restricted cash of $11.8 million as of December 31, 2018. See Note 8 for further details on the nature of the restricted cash. Short-Term Investments The Company's held-to-maturity investments in U.S. government securities, commercial paper, and its overnight repurchase agreement are carried at amortized cost and any premiums or discounts are amortized or accreted through the maturity date of the investment. Any impairment that is not deemed to be temporary is recognized in the period identified. Deferred Offering Costs Deferred offering costs are expenses directly related to the Form S-3 filed with the SEC on August 31, 2018 and declared effective on September 14, 2018. These costs consist of legal, accounting, printing, and filing fees that the Company has capitalized, including fees incurred by the independent registered public accounting firm directly related to the Shelf Registration. Deferred costs associated with the Shelf Registration are reclassified to additional paid in capital on a pro-rata basis when the Company completes offerings under the Shelf Registration, with any remaining deferred offering costs to be charged to the results of operations at the end of the three-year life of the Shelf Registration. During the year ended December 31, 2018, the Company charged $0.2 million to the results of operations for deferred offering costs associated with the Company’s previously effective shelf registration which expired during the period. Warrant Liabilities The Company accounts for the outstanding warrants associated with the June 2016 Public Offering and the March 2018 Public Offering as liabilities measured at fair value. The fair values of these warrants have been determined using the Black-Scholes valuation model ("Black-Scholes"). The warrants are subject to remeasurement at each balance sheet date, using Black-Scholes, with any changes in the fair value of the outstanding warrants recognized in the accompanying statements of operation. See Note 9 for further details. Comprehensive Loss The Company has no items of comprehensive income or loss other than net loss. Revenue Recognition and Deferred Revenue The Company has entered into arrangements involving the sale or license of intellectual property and the provision of other services. When entering into any arrangement involving the sale or license of intellectual property rights and other services, the Company determines whether the arrangement is subject to accounting guidance in ASC 606, Revenue from Contracts with Customers Collaborative Arrangements Analyzing the arrangement to identify performance obligations requires the use of judgment. In arrangements that include the sale or license of intellectual property and other promised services, the Company first identifies if the licenses are distinct from the other promises in the arrangement. If the license is not distinct, the license is combined with other services into a single performance obligation. Factors that are considered in evaluating whether a license is distinct from other promised services include, for example, whether the counterparty can benefit from the license without the promised service on its own or with other readily available resources and whether the promised service is expected to significantly modify or customize the intellectual property. The Company classifies non-refundable upfront payments, milestone payments and royalties received for the sale or license of intellectual property as revenues within its statements of operations because the Company views such activities as being central to its business operations. For the sale of intellectual property that is distinct, fixed consideration and variable consideration are included in the transaction price and recognized in revenue immediately to the extent that it is probable that there would not be a significant reversal of cumulative revenue in the future. For the license of intellectual property that is distinct, fixed and variable consideration (to the extent there will not be a significant reversal in the future) are also recognized immediately in income, except for consideration received in the form of royalty or sales-based milestones, which is recorded when the customer’s subsequent sales or usages occur. If the sale or license of intellectual property is not distinct, revenue is deferred and recognized over the estimated period of the Company’s combined performance obligation. For contractual arrangements that meet the definition of a collaborative arrangement under Topic 808, consideration received for any units-of-account that are outside the scope of Topic 606 are recognized in the statements of operations by considering (i) the nature of the arrangement, (ii) the nature of the Company’s business operations, and (iii) the contractual terms of the arrangement. The Company's August 2013 development, license, and supply agreement with R-Pharm, CJSC (“R-Pharm”), combined with the supplemental arrangement in November 2014 (the “R-Pharm Agreement”), is a collaborative arrangement pursuant to Topic 808. The Company received a non-refundable upfront payment of $1.5 million from R-Pharm in August 2013 which is being recognized over the estimated relationship period of 70 months for the combined performance obligation that includes the license of intellectual property and the participation on a joint steering committee. The Company recognized revenue from this upfront payment of $0.3 million in both the years ended December 31, 2018 and 2017. The Company is entitled to receive other payments under the R-Pharm Agreement including development and sales-based milestones and royalties; however, the variable consideration was fully constrained as of December 31, 2018. In July 2016, the Company entered into an Asset Purchase agreement with UK-based Cypralis Limited (or "Cypralis"), a life sciences company, for the sale of its cyclophilin inhibitor assets. Cypralis also acquired all patents, patent applications and know-how related to the acquired portfolio. In connection with the Asset Purchase agreement, the Company is eligible to receive milestone payments upon the successful progression of Cypralis clinical candidates into later stage clinical studies and royalties payable upon product commercialization. The Company retains the right to repurchase the portfolio assets from Cypralis if abandoned or deprioritized. For the year ended December 31, 2018, there was no revenue recognized associated with this agreement given the variable consideration associated with the sale of intellectual property to Cypralis was fully constrained as of December 31, 2018. Additionally, in October 2014 the Company entered into a license agreement with Waterstone Pharmaceutical HK Limited (or “Waterstone”) and granted Waterstone an exclusive, worldwide license to develop and commercialize certain non-strategic compounds. The Company is entitled to receive potential milestones and royalties from Waterstone and for the year ended December 31, 2018, there was no revenue recognized by the Company associated with this agreement. Research and Development Major components of research and development costs include clinical trial activities and services, including related drug formulation, manufacturing, and other development, preclinical studies, cash compensation, stock-based compensation, fees paid to consultants and other entities that conduct certain research and development activities on the Company’s behalf, materials and supplies, legal services, and regulatory compliance. The Company is required to estimate its expenses resulting from its obligations under contracts with clinical research organizations, clinical site agreements, vendors, and consultants in connection with conducting ibrexafungerp clinical trials and preclinical development. The financial terms of these contracts are subject to negotiations which vary from contract to contract, and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate development and trial expenses in its financial statements by matching those expenses with the period in which the services and efforts are expended. For clinical trials, the Company accounts for these expenses according to the progress of the trial as measured by actual hours expended by CRO personnel, investigator performance or completion of specific tasks, patient progression, or timing of various aspects of the trial. For preclinical development services performed by outside service providers, the Company determines accrual estimates through financial models, taking into account development progress data received from outside service providers and discussions with applicable Company and service provider personnel. Patent Expenses Costs related to filing and pursuing patent applications, as well as costs related to maintaining the Company's existing patent portfolio, are recorded as expense as incurred since recoverability of such expenditures is uncertain. Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, based on the Company’s principal or, in absence of a principal, most advantageous market for the specific asset or liability. The Company uses a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis, as well as assets and liabilities measured at fair value on a non-recurring basis, in periods subsequent to their initial measurement. The hierarchy requires the Company to use observable inputs when available, and to minimize the use of unobservable inputs when determining fair value. The three tiers are defined as follows: • Level 1 — Observable inputs that reflect quoted market prices (unadjusted) for identical assets or liabilities in active markets; • Level 2 — Observable inputs other than quoted prices in active markets that are observable either directly or indirectly in the marketplace for identical or similar assets and liabilities; and • Level 3 — Unobservable inputs that are supported by little or no market data, which require the Company to develop its own assumptions about the assumptions market participants would use in pricing the asset or liability based on the best information available in the circumstances. Amortization of Debt Discount The Company's term loan with Solar Capital Ltd. (“Solar”) is recorded net of debt discount which comprised issuance costs, customary closing and final fees, and the fair value of the warrants issued in conjunction with the term loan (Note 9). The resulting debt discount is being amortized over the term of the term loan using the straight-line method, which approximates the effective interest method, and the amortization of debt discount is included in the accompanying statements of operations. Income Taxes The Company provides for deferred income taxes under the asset and liability method, whereby deferred income taxes result from temporary differences between the tax bases of assets and liabilities and their reported amounts in the financial statements. Valuation allowances are established when necessary to reduce deferred tax assets to the amount that the Company believes is more likely than not to be realized. The Company recognizes uncertain tax positions when the positions will be more likely than not sustained based solely upon the technical merits of the positions. Certain modifications made to an outstanding incentive stock option award at any time after the initial grant dates which are considered to be “material modifications”, as defined within the Internal Revenue Code, may result in the affected award being recharacterized as a non-statutory stock option. The effects of any recharacterization modification for purposes of income tax accounting are recognized on a prospective basis. Stock-Based Compensation The Company measures and recognizes compensation expense for all stock-based payment awards made to employees, officers, and directors based on the estimated fair values of the awards as of grant date. The Company values equity instruments and stock options granted to employees and non-employee directors using the Black-Scholes valuation model. The value of the portion of the award that is ultimately expected to vest is recorded as expense over the requisite service periods. Basic and Diluted Net Loss per Share of Common Stock The Company calculates net loss per common share in accordance with FASB Accounting Standards Codification (“ASC”) ASC Earnings Per Share The following potentially dilutive shares of common stock have not been included in the computation of diluted net loss per share for all periods as the result would be anti-dilutive: December 31, 2018 2017 Warrants to purchase Series C-1 Preferred 14,033 14,033 Warrants to purchase common stock associated with June 2016 Public Offering 4,218,750 4,218,750 Warrants to purchase common stock associated with Solar loan agreement 122,435 122,435 Warrants to purchase common stock associated with March 2018 Public Offering - Series 1 13,198,075 — Warrants to purchase common stock associated with March 2018 Public Offering - Series 2 7,988,175 — Stock options 4,052,913 3,075,994 Segment and Geographic Information Operating segments are defined as components of an enterprise (business activity from which it earns revenue and incurs expenses) about which discrete financial information is available and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker (“CODM”) is the Chief Executive Officer. The CODM reviews consolidated operating results to make decisions about allocating resources and assessing performance for the entire Company. The Company views its operations and manages its business as one operating segment. All assets of the Company were held in the United States for the years ended December 31, 2018 and 2017. Although all operations are based in the United States, the Company generated a portion of its revenue from R-Pharm outside of the United States. All of the Company's revenue was generated from a non-refundable upfront payment received under a licensing and collaboration arrangement with a partner located in Russia. All sales, including sales outside of the United States, are denominated in United States dollars. Reclassification of Prior Year Amounts Certain prior year amounts have been reclassified for consistency with the current year presentation. Effect of Recent Accounting Pronouncements In February 2016, the FASB issued Accounting Standards Update ("ASU") No. 2016-02, Leases, or ASU 2016-02. The new guidance requires lessees to recognize the assets and liabilities arising from leases on the balance sheet. For public companies, ASU 2016-02 is effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2018, and early adoption is permitted. In July 2018, the FASB issued ASU No. 2018-11, Leases, Targeted Improvements, which provides entities with an additional (and optional) transition method to adopt ASU 2016-02. The Company expects to recognize a right of use asset and corresponding lease liability for the operating lease for its corporate headquarters further disclosed in Note 8. The practical expedients under ASC 842-10-65-1(f) and ASC 842-10-15-37 are also expected to be utilized as part of the implementation and the Company will recognize the cumulative-effect adjustment as of January 1, 2019, the first reporting report in which the Company is applying ASU 2016-02. 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, or ASU 2018-13, which modifies the disclosure requirements on fair value measurements. ASU 2018-13 is effective for us in the first quarter of fiscal 2020, and earlier adoption is permitted. We are currently evaluating the impact of our pending adoption of ASU 2018-13 on our consolidated financial statements.

Short-term Investments

Short-term Investments	12 Months Ended
	Dec. 31, 2018
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, 2018 (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value As of December 31, 2017 U.S. government securities $ 11,462 $ 74 $ (79 ) $ 11,457 Commercial paper 11,962 — — 11,962 Overnight repurchase agreement 9,000 — — 9,000 Total short-term investments $ 32,424 $ 74 $ (79 ) $ 32,419 Amortized Cost Unrealized Gains Unrealized Losses Fair Value As of December 31, 2018 U.S. government securities 14,946 14 (15 ) 14,945 Commercial paper 8,772 — — 8,772 Overnight repurchase agreement 9,000 — — 9,000 Total short-term investments $ 32,718 14 (15 ) $ 32,717 As of December 31, 2018, the Company has $32.7 million of held-to-maturity investments with contractual maturities less than one year. The gross unrealized gains and losses for the Company's commercial paper and overnight repurchase agreement are not significant

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2018
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): December 31, 2018 2017 Prepaid research and development services $ 245 $ 384 Prepaid insurance 200 279 Other prepaid expenses 20 62 Other receivable due from R-Pharm — 251 NOL sale receivable (see Note 10) 6,732 — Other current assets 54 91 Total prepaid expenses and other current assets $ 7,251 $ 1,067

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Property and Equipment	5. Property and Equipment Property and equipment consisted of the following (in thousands): December 31, 2018 2017 Furniture and fixtures $ 406 $ — Computer equipment 73 12 Other 98 — 577 12 Less: accumulated depreciation and amortization (61 ) (8 ) Total property and equipment $ 516 $ 4

Accrued Expense

Accrued Expense	12 Months Ended
	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued Expense	6 . Accrued Expense Accrued expenses consisted of the following (in thousands): December 31, 2018 2017 Accrued research and development expenses $ 587 $ 609 Accrued employee bonus compensation 1,197 763 Employee withholdings 21 29 Other accrued expenses 298 304 Total accrued expenses $ 2,103 $ 1,705

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Borrowings	7 . Borrowings On September 30, 2016, the Company entered into a loan agreement with 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%. Pursuant to the loan agreement, on September 30, 2016 (the "Closing Date"), the Company issued to Solar a warrant (the “Solar Warrant”) to purchase an aggregate of up to 122,435 shares of the Company’s common stock at an exercise price of $3.6754 per share. The Solar Warrant will expire five years from the date of the grant. The Solar Warrant is classified as equity and was recorded at its relative fair value at issuance in the stockholders' equity section of the balance sheet (See Note 9). On March 7, 2019, the Company entered into a Senior Convertible Note Purchase Agreement (the “Note Purchase Agreement”) with Puissance Life Science Opportunities Fund VI (Puissance). Pursuant to the Note Purchase Agreement, on March 7, 2019, the Company issued and sold to the investor $16 million aggregate principal amount of its 6.0% Convertible Senior Notes due 2025 (the “Note”) and the Company used the cash proceeds to pay the remaining outstanding Solar Term Loan in full (see Note 14 for further details).

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	8 . Commitments and Contingencies Leases On July 13, 2015, the Company entered into a sublease (the "Sublease") that became effective July 22, 2015, to sublet certain premises consisting of 10,141 square feet of space (the "Subleased Premises") located at 101 Hudson Street, Jersey City, New Jersey from Optimer Pharmaceuticals, Inc. The term of the Sublease commenced on August 1, 2015 (the "Commencement Date") and expired on July 30, 2018. No base rent was due under the Sublease until one month after the Commencement Date. Under the Sublease, the Company was obligated to pay monthly base rent of approximately twenty-five thousand dollars per month, which amount increases by 3% annually on each anniversary of the Commencement Date. In addition, the Company was required to fund a security deposit with the sublandlord in the amount of $0.1 million. 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. The lease term is eleven years from 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 periods from the end of the first term. Under the lease, the Company must furnish a security deposit in the form of a standby letter of credit in the amount of $0.3 million, which will be reduced by fifty-five thousand dollars every two years for ten years after the commencement of the lease. The security deposit is classified as restricted cash in the accompanying balance sheets . Rent expense was approximately $0.5 million and $0.3 million for the years ended December 31, 2018 and 2017, respectively. Future minimum lease payments for all operating leases as of December 31, 2018 are as follows (in thousands): 2019 498 2020 508 2021 518 2022 529 2023 716 Thereafter 4,203 Total $ 6,972 License Arrangements with Potential Future Expenditures As of December 31, 2018, the Company had a license arrangement with Merck Sharp & Dohme Corp., or Merck, as amended, that involves potential future expenditures. Under the license arrangement, executed in May 2013, the Company exclusively licensed from Merck its rights to ibrexafungerp in the field of human health. In January 2014, Merck assigned the patents related to ibrexafungerp that it had exclusively licensed to the Company. 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 royalties 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 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 Company has two additional licensing agreements for other compounds that could require it to make payments of up to $2.3 million upon achievement of certain milestones by the Company. Clinical Development Arrangement 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. Legal Proceeding On March 8, 2017, a purported stockholder class action lawsuit was filed in the United States District Court for the District of New Jersey against the Company and certain of its current and former officers, captioned Gibson v. Scynexis, Inc., et al. On October 26, 2018, the class action lawsuit was dismissed.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	9 . Stockholders' Equity Authorized, Issued, and Outstanding Common Shares The Company’s common stock has a par value of $0.001 per share and consists of 125,000,000 authorized shares as of December 31, 2018 and 2017, respectively; 47,971,989 and 28,971,651 shares were issued and outstanding as of December 31, 2018 and 2017, respectively. Shares Reserved for Future Issuance The Company had reserved shares of common stock for future issuance as follows: December 31, 2018 2017 Outstanding stock options 4,052,913 3,075,994 Outstanding restricted stock units 111,891 64,365 Outstanding Series C-1 Preferred warrants 14,033 14,033 Warrants to purchase common stock associated with June 2016 Public Offering 4,218,750 4,218,750 Warrants to purchase common stock associated with March 2018 Public Offering - Series 1 13,198,075 — Warrants to purchase common stock associated with March 2018 Public Offering - Series 2 7,988,175 — Warrants to purchase common stock associated with Solar loan agreement 122,435 122,435 For possible future issuance under 2014 Equity Incentive Plan (Note 10) 612,018 492,382 For possible future issuance under 2014 Employee Stock Purchase Plan (Note 10) 81,667 83,617 For possible future issuance under 2015 Inducement Plan (Note 10) 5,000 5,000 Total common shares reserved for future issuance 30,404,957 8,076,576 Liquidation Rights In the event of any liquidation or dissolution of the Company, the holders of the common stock are entitled to the remaining assets of the Company legally available for distribution. Dividends and Voting Rights The holders of the common stock are entitled to receive dividends if and when declared by the Company. Preferred Stock On May 7, 2014, the Company amended and restated its articles of incorporation relating to its approved capital structure. The Company's board of directors has authorized the Company, subject to limitations prescribed by Delaware law, to issue up to 5,000,000 shares of preferred stock with a par value of $0.001 per share in one or more series, to establish from time to time the number of shares to be included in each series and to fix the designation, powers, preferences and rights of the shares of each series and any of its qualifications, limitations or restrictions. The Company's board of directors can also increase or decrease the number of shares of any series of preferred stock, but not below the number of shares of that series then outstanding, without any further vote or action by the stockholders. The Company's board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of the common stock. There were no shares of preferred stock issued and outstanding as of December 31, 2018 and 2017. Warrants Associated with Convertible Preferred Stock Issuances In July 2006, the Company issued warrants to purchase 196,923 shares of Series C-1 Preferred Stock, which converted into the right to purchase 14,033 shares of common stock in connection with our IPO, however, we refer to these warrants as our Series C-1 Preferred warrants. The Series C-1 Preferred warrants were issued in conjunction with a loan financing agreement with an original exercise price of $3.25 per share of Series C-1 Preferred, which converted into an exercise price of $45.61 per share of common stock in connection with our IPO. These warrants remain outstanding as of December 31, 2018 and will expire on May 7, 2019, which is the five year anniversary of the Company's IPO. The fair value at the date of grant for these instruments was $0.5 million, which was recorded as a debt discount. The debt discount related to these warrants was fully amortized as of December 31, 2010. The Company determined that the warrants should be recorded as a derivative liability and stated at fair value at each reporting period. As of December 31, 2018 and 2017, the fair value of the warrant derivative liability was zero. Warrants Associated with June 2016 and March 2018 Public Offerings On June 21, 2016, the Company completed the June 2016 Public Offering and sold 9,375,000 shares of its common stock and warrants to purchase up to 4,218,750 shares of the Company’s common stock. Each purchaser received a warrant to purchase 0.45 of a share for each share purchased in the June 2016 Public Offering. There is not expected to be any trading market for the warrants. Each warrant was exercisable immediately upon issuance, will expire five years from the date of issuance, and has an exercise price of $3.00 per share. On March 8, 2018, the Company completed the March 2018 Public Offering and sold 17,751,500 shares of its common stock and warrants to purchase up to 21,301,800 shares of the Company’s common stock. Each purchaser received a warrant to purchase 0.75 of a share of common stock (the “Series 1 warrants”) and 0.45 of a share of common stock (the “Series 2 warrants”) for each share purchased in the March 2018 Public Offering. The Series 1 warrants to purchase in the aggregate up to 13,313,625 shares of common stock have a 53-week term and an exercise price of $1.85 per share, and the Series 2 warrants to purchase in the aggregate up to 7,988,175 shares of common stock have a five-year term and an exercise price of $2.00 per share. There is not expected to be any market for the warrants and each warrant is exercisable immediately upon issuance, subject to certain limitations on beneficial ownership. During the year ended December 31, 2018, there were 115,550 of the Series 1 warrants exercised for total proceeds of $0.2 million. The Series 1 warrants expire on March 14, 2019. The warrants 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 requires that these warrants be classified as liabilities. The fair values of these warrants have been determined using the Black-Scholes valuation model, and the changes in the fair value are recorded in the accompanying statements of operations. During the year ended December 31, 2018, the Company recorded a gain of $11.9 million due to the change in fair value of the warrant liability. As of December 31, 2018, the fair value of the warrant liabilities was $1.0 million. Warrant Associated with Solar Loan Agreement Pursuant to a loan agreement, on the closing date the Company issued to Solar the a warrant to purchase an aggregate of up to 122,435 shares of the Company’s common stock at an exercise price of $3.6754 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.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	10 . Income Taxes The Company’s financial statements include total tax benefit of $6.7 million and $0 on loss before taxes of $19.2 million and $25.1 million for the years ended December 31, 2018 and 2017, respectively. Reconciliations of the differences between the benefit for income taxes and income taxes at the statutory U.S. federal income tax rate is as follows (dollars in thousands): 2018 2017 Amount Percent of Pretax Income Amount Percent of Pretax Income Income taxes from continuing operations at statutory rate $ (4,033 ) 21.0 % $ (8,520 ) 34.0 % State income taxes (985 ) 5.1 % (1,075 ) 4.3 % State effect of permanent items (585 ) 3.0 % (112 ) 0.4 % Stock-based compensation 94 (0.5 )% 35 (0.1 )% Deferred rate change 438 (2.3 )% 23,776 (94.9 )% Warrants issuance (2,492 ) 13.0 % (928 ) 3.7 % Other 71 (0.34 )% 828 (3.3 )% NOL sale (3,938 ) 20.5 % — — Increase in valuation allowance 4,694 (24.4 )% (14,004 ) 55.9 % Total income tax benefit $ (6,736 ) 35.1 % $ — — % The components of deferred tax assets and liabilities as of December 31, 2018 and 2017 are as follows (in thousands): December 31, 2018 2017 Current deferred tax assets: Accrued expenses $ — $ 182 Stock-based compensation — 1,309 Other — 49 — 1,540 Noncurrent deferred tax assets (liabilities) Accrued expenses 132 — Stock-based compensation 1,911 — Other (31 ) — Net operating loss carryforwards 44,730 40,504 Research and development credits 3,226 3,230 49,968 43,734 Total deferred tax assets 49,968 45,274 Valuation allowances (49,968 ) (45,274 ) Net deferred tax assets $ — $ — As of December 31, 2018 and 2017, the Company had available federal net operating loss ("NOL") carryforwards of approximately $194.9 million and $171.5 million, respectively, and state loss carryforwards of approximately $150.8 million and $166.4 million, respectively. Approximately $171.9 million of the federal NOLs can be carried forward to future tax years and expire in 2038. The federal NOL generated in December 31, 2018 of approximately $23.0 million is carried forward indefinitely and does not expire. The Company’s state loss carryforwards began to expire in 2017. As of December 31, 2018, the Company had available federal research and development credit carryforwards of $3.1 million which begin to expire in 2022. The Company was eligible to receive cash from the sale of its Net Operating Losses under the New Jersey Technology Business Tax Certificate (NOL) Program On December 22, 2017, the President signed into law the "Tax Cuts and Jobs Act.” The new tax reform has the following effects on the company: (1) permanently reduces the maximum corporate income tax rate from 35% to 21% effective for tax years beginning after December 31, 2017 (2) allows temporary 100% expensing for certain business assets and property placed in service after September 27, 2017 and before January 1, 2023 (3) disallows NOL carrybacks but allows for the indefinite carryforward of those NOLs which applies to losses arising in tax years beginning after December 31, 2017 and (4) limits NOL deductions for each year equal to the lesser of the available carryover or 80% of a taxpayer's pre-NOL deduction taxable income. This applies to losses arising in tax years beginning after December 31, 2017. As of December 31, 2018 and 2017, the Company has concluded that it is more likely than not that the Company will not realize the benefit of its deferred tax assets due to its history of losses. Accordingly, the net deferred tax assets have been fully reserved. In accordance with Section 382 of the Internal Revenue Code of 1986, as amended, a change in equity ownership of greater than 50% within a three-year period results in an annual limitation on the Company’s ability to utilize its NOL carryforwards created during the tax periods prior to the change in ownership. The Company has determined that ownership changes have occurred and as a result, a portion of the Company’s NOL carryforwards are limited. Because the Company has incurred cumulative net operating losses since inception, all tax years remain open to examination by U.S. federal and state income tax authorities. The Company applies ASC 740-10-25-5, Income Taxes Accounting for Uncertainty in Income Taxes The following is a tabular reconciliation of the total amounts of unrecognized tax benefits as of December 31, 2018 and 2017 (in thousands): December 31, 2018 2017 Unrecognized tax benefit—January 1 $ 436 $ 623 Additions for tax positions of current period — — Additions for tax positions of prior periods — — Deferred rate change — (187 ) Unrecognized tax benefit—December 31 $ 436 $ 436 None of the unrecognized tax benefits would, if recognized, affect the effective tax rate because the Company has recorded a valuation allowance to fully offset federal and state deferred tax assets. The Company has no tax positions for which it is reasonably possible that the total amount of unrecognized tax benefits will significantly increase or decrease within the coming year. The Company has $0 provided for interest and penalties associated with uncertain tax positions.

Stock-based Compensation

Stock-based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation	11 . Stock-based Compensation 2009 Stock Option Plan The Company had a share-based compensation plan (the “2009 Stock Option Plan”) under which the Company granted options to purchase shares of common stock to employees, directors, and consultants as either incentive stock options or nonqualified stock options. Incentive stock options could be granted with exercise prices not less than 100% to 110% of the fair market value of the common stock. Options granted under the plan generally vest over three to four years and expire in 10 years from the date of grant. 2014 Equity Incentive Plan In February 2014, the Company’s board of directors adopted the 2014 Equity Incentive Plan, or the 2014 Plan, which was subsequently ratified by its stockholders and became effective on May 2, 2014 (the “Effective Date”). The 2014 Plan, as amended on June 18, 2014 and February 25, 2015, is the successor to and continuation of the 2009 Stock Option Plan. As of the Effective Date, no additional awards will be granted under the 2009 Stock Option Plan, but all stock awards granted under the 2009 Stock Option Plan prior to the Effective Date will remain subject to the terms of the 2009 Stock Option Plan. All awards granted on and after the Effective Date will be subject to the terms of the 2014 Plan. The 2014 Plan provides for the grant of the following awards: (i) incentive stock options, (ii) nonstatutory stock options, (iii) stock appreciation rights, (iv) restricted stock awards, (v) restricted stock unit awards, and (vi) other stock awards. Employees, directors, and consultants are eligible to receive awards. Options granted under the plan generally vest over three to four years and expire in 10 years from the date of grant. Under the 2014 Plan, after giving effect to the increases to the share reserve approved by the Company’s stockholders in September 2014, and June 2015, but excluding the automatic increases discussed below, the aggregate number of shares of common stock that could be issued from and after the Effective Date (the “share reserve”) could not exceed the sum of (i) 1,122,731 new shares, (ii) the shares that represented the 2009 Stock Option Plan’s available reserve on the Effective Date, and (iii) any returning shares from the 2009 Stock Option Plan. Under the 2014 Plan, the share reserve will automatically increase on January 1st of each year, for a period of not more than 10 years, commencing on January 1, 2015, and ending on January 1, 2024, in an amount equal to 4.0% of the total number of shares of capital stock outstanding on December 31st of the preceding calendar year. The board of directors may act prior to January 1st of a given year to provide that there will be no increase in the share reserve or that the increase will be a lesser number of shares than would otherwise occur. Pursuant to the terms of the 2014 Plan, on January 1, 2018 and 2017, the Company automatically added 1,158,866 and 984,376 shares to the total number shares of common stock available for future issuance under the 2014 Plan, respectively. As of December 31, 2018, there were 612,018 shares of common stock available for future issuance under the 2014 Plan. 2015 Inducement Plan On March 26, 2015, the Company's board of directors adopted the 2015 Inducement Plan (the "2015 Plan"). The 2015 Plan provides for the grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, and other forms of equity compensation (collectively, stock awards), all of which may be granted to persons not previously employees or directors of the Company, or following a bona fide period of non-employment, as an inducement material to the individuals’ entering into employment with the Company within the meaning of NASDAQ Listing Rule 5635(c)(4). The 2015 Plan has a share reserve covering 450,000 shares of common stock. During the year ended December 31, 2018, there were no granted options of the Company's common stock under the 2015 Inducement Plan. As of December 31, 2018, there were 5,000 shares of common stock available for future issuance under the 2015 Plan. Option Valuation Method The fair value of a stock option is estimated using an option-pricing model that takes into account as of the grant date the exercise price and expected life of the option, the current price of the underlying stock and its expected volatility, expected dividends on the stock, and the risk-free interest rate for the expected term of the option. The Company has used the simplified method in calculating the expected term of all option grants based on the vesting period. Compensation costs related to share-based payment transactions are recognized in the financial statements upon satisfaction of the requisite service or vesting requirements and forfeitures are recorded as incurred. The Company has elected to use the Black-Scholes option-pricing model. The Black-Scholes option-pricing model was developed for use in estimating the fair value of traded options that have no vesting restrictions and are fully transferable rather than for use in estimating the fair value of stock options subject to vesting and transferability restrictions. Using the Black-Scholes option-pricing model, the weighted-average fair value of options granted during 2018 and 2017 was $0.90 and $1.39 per option, respectively. The aggregate fair value of options granted during 2018 and 2017 was $1.1 million and $1.8 million, respectively. The assumptions used to estimate fair value and the resulting grant date fair values are as follows: Employees Non-employee Directors Years Ended December 31, Years Ended December 31, 2018 2017 2018 2017 Weighted average expected volatility 52.31 % 51.38 % 58.65 % 53.86 % Weighted average risk-free interest rate 2.64 % 2.07 % 2.44 % 2.01 % Weighted average expected term (in years) 6.02 6.04 5.28 5.37 The activity for the 2009 Plan, 2014 Plan and 2015 Plan for the years ended December 31, 2018 and 2017 is summarized as follows: Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value ($000) Outstanding — January 1, 2017 1,819,444 $ 7.52 6.98 $ 32 Granted 1,256,770 $ 2.80 Exercised — Forfeited/expired (220 ) $ 9.64 Outstanding — December 31, 2017 3,075,994 $ 5.59 7.23 $ 151 Exercisable — December 31, 2017 1,602,114 $ 7.19 5.78 $ 15 Vested or expected to vest — December 31, 2017 3,075,994 $ 5.59 7.23 $ 151 Outstanding — January 1, 2018 3,075,994 $ 5.59 7.23 $ 151 Granted 1,259,530 $ 1.73 Exercised — Forfeited/expired (282,611 ) $ 5.81 Outstanding — December 31, 2018 4,052,913 $ 4.37 7.23 — Exercisable — December 31, 2018 2,323,907 $ 5.77 6.24 — Vested or expected to vest —December 31, 2018 4,052,913 $ 4.37 7.23 — The intrinsic values in the table above represent the total intrinsic value (the difference between the Company’s closing stock price as of December 31, 2018 and 2017, and the exercise price multiplied by the number of options). The total fair value of shares vested during the years ended December 31, 2018 and 2017 was $1.8 million and $1.6 million, respectively. As of December 31, 2018, there was approximately $2.1 million of total unrecognized compensation cost related to unvested share-based compensation arrangements granted under the plan. That cost is expected to be recognized over a weighted-average period of 2.15 years. Restricted stock unit ("RSU") activity under the 2014 Plan for the year ended December 31, 2018, is summarized as follows: Number of Shares Weighted Average Grant Date Fair Value Per Share Non-vested at December 31, 2017 64,365 $ 2.70 Granted 68,000 1.65 Vested (14,785 ) 2.68 Forfeited (5,689 ) 2.89 Non-vested at December 31, 2018 111,891 $ 2.06 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 period from the date of grant. 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. As of December 31, 2018, there was approximately $0.2 million of total unrecognized compensation cost related to unvested RSU share-based compensation. That cost is expected to be recognized over a weighted-average period of 2.73 years. 2014 Employee Stock Purchase Plan In February 2014, the Company’s board of directors adopted the 2014 Employee Stock Purchase Plan (“ESPP”), which was subsequently ratified by the Company’s stockholders and became effective on May 2, 2014. The purpose of the ESPP is to provide means by which eligible employees of the Company and of certain designated related corporations may be given an opportunity to purchase shares of the Company’s common stock, and to seek and retain services of new and existing employees and to provide incentives for such persons to exert maximum efforts for the success of the Company. Common stock that may be issued under the ESPP will not exceed 47,794 shares, plus the number of shares of common stock that are automatically added on January 1st of each year for a period of ten years, commencing on January 1, 2015 and ending on January 1, 2024, in an amount equal to the lesser of (i) 0.8% of the total number of shares of outstanding common stock on December 31 of the preceding calendar year, and (ii) 29,411 shares of common stock. Similar to the 2014 Plan, the board of directors may act prior to January 1st of a given year to provide that there will be no increase in the share reserve or that the increase will be a lesser number of shares than would otherwise occur. The ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the Internal Revenue Code. During the years ended December 31, 2018 and 2017, the Company issued 31,361 and 18,132 shares of common stock under the ESPP, respectively. During the years ended December 31, 2018 and 2017, the number of shares of common stock available for issuance under the ESPP was automatically increased by 29,411 shares. As of December 31, 2018, there were 81,667 shares of common stock available for future issuance under the ESPP. Compensation Cost The compensation cost that has been charged against income for stock awards under the 2009 Stock Option Plan, the 2014 Plan, and the ESPP was $1.8 million and $1.7 million for the years ended December 31, 2018 and 2017, respectively. The total income tax benefit recognized in the statements of operations for share-based compensation arrangements was $0 for the years ended December 31, 2018 and 2017, respectively. Cash received from options exercised was $0 for both the years ended December 31, 2018 and 2017. Stock-based compensation expense related to stock options is included in the following line items in the accompanying statements of operations (in thousands): Years Ended December 31, 2018 2017 Research and development, net $ 519 $ 458 Selling, general and administrative 1,297 1,204 Total stock-based compensation expense $ 1,816 $ 1,662

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	12 . Fair Value Measurements The carrying amounts of certain financial instruments, including cash and cash equivalents, 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, pursuant to the policy described in Note 2. This determination requires significant judgments to be made. The following table summarizes the conclusions reached as of December 31, 2018 and 2017 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) December 31, 2017 Cash on deposit $ 1,316 $ 1,316 — — Money market funds 10,153 10,153 — — Total assets $ 11,469 $ 11,469 — — Warrant liability $ 3,872 — — $ 3,872 Total liabilities $ 3,872 $ — — $ 3,872 December 31, 2018 Cash $ 213 $ 213 — — Restricted cash 328 328 — — Money market funds 11,226 11,226 — — Total assets $ 11,767 $ 11,767 — — Warrant liability $ 986 — — $ 986 Total liabilities $ 986 — — $ 986 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 liability 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 liability 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. 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): December 31, 2018 Balance - January 1, 2018 $ 3,872 March 2018 Public Offering - Series 1 Warrants 3,480 March 2018 Public Offering - Series 2 Warrants 5,500 Gain adjustment to fair value (11,866 ) Balance - December 31, 2018 $ 986

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	13 . Employee Benefit Plan The Company has a 401(k) retirement plan, which covers all U.S. employees scheduled for and working more than 20 hours per week. The Company may provide a discretionary match with a maximum amount of 50% of the first 6% of eligible participant’s compensation, which vests ratably over four years. Contributions under the plan were approximately $0.1 million for the years ended December 31, 2018 and 2017.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events Pursuant to the terms of the 2014 Plan (see Note 11), on January 1, 2019, the Company automatically added 1,918,879 shares to the total number shares of common stock available for future issuance under the 2014 Plan. Pursuant to the terms of the 2014 ESPP (see Note 11), on January 1, 2019, the Company automatically added 29,411 shares to the total number shares of common stock available for future issuance under the 2014 ESPP. On January 3, 2019, the Company received a cash receipt of $6.7 million for the sale of a portion of our NOLs. This sale was structured through the New Jersey Technology Business Tax Certificate Transfer (NOL) Program. On March 7, 2019, the Company entered into a Note Purchase Agreement with Puissance. Pursuant to the Note Purchase Agreement, on March 7, 2019, the Company issued and sold to Puissance $16 million aggregate principal amount of its Note and the Company used the cash proceeds to pay the remaining outstanding Solar Term Loan in full. The Note was issued and sold for cash at a purchase price equal to 100% of their principal amount, in reliance on the exemption from registration provided by Section 4(a)(2) of the Securities Act of 1933, as amended (the “ ” The holders of the Note may convert their Note 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 739.0983 shares of common stock per $1,000 principal amount of the Note, which is equivalent to an initial conversion price of approximately $1.35, and is subject to adjustment in certain events described in the Note Purchase Agreement. Holders who convert 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 for a holder who elects to convert the Note 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 Note, including those delivered in connection with an interest make-whole payment, will not exceed a cap of 813 shares of common stock per $1,000 principal amount of the Note. On or after March 15, 2022, the Company has the right, at its election, to redeem all or any portion of the Note 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 Note to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If a “ ”

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially expose the Company to concentrations of credit risk, consist principally of cash on deposit, cash equivalents, and short-term investments. The Company's money market fund investment (recognized as cash and cash equivalents) and short-term investments are with what the Company believes to be high quality issuers. The Company has not experienced any significant losses in such accounts. Revenue recognized from a non-refundable upfront payment from R-Pharm, CJSC (“R-Pharm”), a collaboration partner, accounted for 100% of the Company's revenue for the years ended December 31, 2018 and 2017. No other parties contributed to the Company's revenue in 2018 and 2017.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers any highly liquid investments with a remaining maturity of three months or less when purchased to be cash and cash equivalents. The Company reported cash, cash equivalents, and restricted cash of $11.8 million as of December 31, 2018. See Note 8 for further details on the nature of the restricted cash.
Short-Term Investments	Short-Term Investments The Company's held-to-maturity investments in U.S. government securities, commercial paper, and its overnight repurchase agreement are carried at amortized cost and any premiums or discounts are amortized or accreted through the maturity date of the investment. Any impairment that is not deemed to be temporary is recognized in the period identified.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs are expenses directly related to the Form S-3 filed with the SEC on August 31, 2018 and declared effective on September 14, 2018. These costs consist of legal, accounting, printing, and filing fees that the Company has capitalized, including fees incurred by the independent registered public accounting firm directly related to the Shelf Registration. Deferred costs associated with the Shelf Registration are reclassified to additional paid in capital on a pro-rata basis when the Company completes offerings under the Shelf Registration, with any remaining deferred offering costs to be charged to the results of operations at the end of the three-year life of the Shelf Registration. During the year ended December 31, 2018, the Company charged $0.2 million to the results of operations for deferred offering costs associated with the Company’s previously effective shelf registration which expired during the period.
Warrant Liabilities	Warrant Liabilities The Company accounts for the outstanding warrants associated with the June 2016 Public Offering and the March 2018 Public Offering as liabilities measured at fair value. The fair values of these warrants have been determined using the Black-Scholes valuation model ("Black-Scholes"). The warrants are subject to remeasurement at each balance sheet date, using Black-Scholes, with any changes in the fair value of the outstanding warrants recognized in the accompanying statements of operation. See Note 9 for further details.
Comprehensive Loss	Comprehensive Loss The Company has no items of comprehensive income or loss other than net loss.
Revenue Recognition and Deferred Revenue	Revenue Recognition and Deferred Revenue The Company has entered into arrangements involving the sale or license of intellectual property and the provision of other services. When entering into any arrangement involving the sale or license of intellectual property rights and other services, the Company determines whether the arrangement is subject to accounting guidance in ASC 606, Revenue from Contracts with Customers Collaborative Arrangements Analyzing the arrangement to identify performance obligations requires the use of judgment. In arrangements that include the sale or license of intellectual property and other promised services, the Company first identifies if the licenses are distinct from the other promises in the arrangement. If the license is not distinct, the license is combined with other services into a single performance obligation. Factors that are considered in evaluating whether a license is distinct from other promised services include, for example, whether the counterparty can benefit from the license without the promised service on its own or with other readily available resources and whether the promised service is expected to significantly modify or customize the intellectual property. The Company classifies non-refundable upfront payments, milestone payments and royalties received for the sale or license of intellectual property as revenues within its statements of operations because the Company views such activities as being central to its business operations. For the sale of intellectual property that is distinct, fixed consideration and variable consideration are included in the transaction price and recognized in revenue immediately to the extent that it is probable that there would not be a significant reversal of cumulative revenue in the future. For the license of intellectual property that is distinct, fixed and variable consideration (to the extent there will not be a significant reversal in the future) are also recognized immediately in income, except for consideration received in the form of royalty or sales-based milestones, which is recorded when the customer’s subsequent sales or usages occur. If the sale or license of intellectual property is not distinct, revenue is deferred and recognized over the estimated period of the Company’s combined performance obligation. For contractual arrangements that meet the definition of a collaborative arrangement under Topic 808, consideration received for any units-of-account that are outside the scope of Topic 606 are recognized in the statements of operations by considering (i) the nature of the arrangement, (ii) the nature of the Company’s business operations, and (iii) the contractual terms of the arrangement. The Company's August 2013 development, license, and supply agreement with R-Pharm, CJSC (“R-Pharm”), combined with the supplemental arrangement in November 2014 (the “R-Pharm Agreement”), is a collaborative arrangement pursuant to Topic 808. The Company received a non-refundable upfront payment of $1.5 million from R-Pharm in August 2013 which is being recognized over the estimated relationship period of 70 months for the combined performance obligation that includes the license of intellectual property and the participation on a joint steering committee. The Company recognized revenue from this upfront payment of $0.3 million in both the years ended December 31, 2018 and 2017. The Company is entitled to receive other payments under the R-Pharm Agreement including development and sales-based milestones and royalties; however, the variable consideration was fully constrained as of December 31, 2018. In July 2016, the Company entered into an Asset Purchase agreement with UK-based Cypralis Limited (or "Cypralis"), a life sciences company, for the sale of its cyclophilin inhibitor assets. Cypralis also acquired all patents, patent applications and know-how related to the acquired portfolio. In connection with the Asset Purchase agreement, the Company is eligible to receive milestone payments upon the successful progression of Cypralis clinical candidates into later stage clinical studies and royalties payable upon product commercialization. The Company retains the right to repurchase the portfolio assets from Cypralis if abandoned or deprioritized. For the year ended December 31, 2018, there was no revenue recognized associated with this agreement given the variable consideration associated with the sale of intellectual property to Cypralis was fully constrained as of December 31, 2018. Additionally, in October 2014 the Company entered into a license agreement with Waterstone Pharmaceutical HK Limited (or “Waterstone”) and granted Waterstone an exclusive, worldwide license to develop and commercialize certain non-strategic compounds. The Company is entitled to receive potential milestones and royalties from Waterstone and for the year ended December 31, 2018, there was no revenue recognized by the Company associated with this agreement.
Research and Development	Research and Development Major components of research and development costs include clinical trial activities and services, including related drug formulation, manufacturing, and other development, preclinical studies, cash compensation, stock-based compensation, fees paid to consultants and other entities that conduct certain research and development activities on the Company’s behalf, materials and supplies, legal services, and regulatory compliance. The Company is required to estimate its expenses resulting from its obligations under contracts with clinical research organizations, clinical site agreements, vendors, and consultants in connection with conducting ibrexafungerp clinical trials and preclinical development. The financial terms of these contracts are subject to negotiations which vary from contract to contract, and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate development and trial expenses in its financial statements by matching those expenses with the period in which the services and efforts are expended. For clinical trials, the Company accounts for these expenses according to the progress of the trial as measured by actual hours expended by CRO personnel, investigator performance or completion of specific tasks, patient progression, or timing of various aspects of the trial. For preclinical development services performed by outside service providers, the Company determines accrual estimates through financial models, taking into account development progress data received from outside service providers and discussions with applicable Company and service provider personnel.
Patent Expenses	Patent Expenses Costs related to filing and pursuing patent applications, as well as costs related to maintaining the Company's existing patent portfolio, are recorded as expense as incurred since recoverability of such expenditures is uncertain.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, based on the Company’s principal or, in absence of a principal, most advantageous market for the specific asset or liability. The Company uses a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis, as well as assets and liabilities measured at fair value on a non-recurring basis, in periods subsequent to their initial measurement. The hierarchy requires the Company to use observable inputs when available, and to minimize the use of unobservable inputs when determining fair value. The three tiers are defined as follows: • Level 1 — Observable inputs that reflect quoted market prices (unadjusted) for identical assets or liabilities in active markets; • Level 2 — Observable inputs other than quoted prices in active markets that are observable either directly or indirectly in the marketplace for identical or similar assets and liabilities; and • Level 3 — Unobservable inputs that are supported by little or no market data, which require the Company to develop its own assumptions about the assumptions market participants would use in pricing the asset or liability based on the best information available in the circumstances.
Amortization of Debt Discount	Amortization of Debt Discount The Company's term loan with Solar Capital Ltd. (“Solar”) is recorded net of debt discount which comprised issuance costs, customary closing and final fees, and the fair value of the warrants issued in conjunction with the term loan (Note 9). The resulting debt discount is being amortized over the term of the term loan using the straight-line method, which approximates the effective interest method, and the amortization of debt discount is included in the accompanying statements of operations.
Income Taxes	Income Taxes The Company provides for deferred income taxes under the asset and liability method, whereby deferred income taxes result from temporary differences between the tax bases of assets and liabilities and their reported amounts in the financial statements. Valuation allowances are established when necessary to reduce deferred tax assets to the amount that the Company believes is more likely than not to be realized. The Company recognizes uncertain tax positions when the positions will be more likely than not sustained based solely upon the technical merits of the positions. Certain modifications made to an outstanding incentive stock option award at any time after the initial grant dates which are considered to be “material modifications”, as defined within the Internal Revenue Code, may result in the affected award being recharacterized as a non-statutory stock option. The effects of any recharacterization modification for purposes of income tax accounting are recognized on a prospective basis.
Stock-Based Compensation	Stock-Based Compensation The Company measures and recognizes compensation expense for all stock-based payment awards made to employees, officers, and directors based on the estimated fair values of the awards as of grant date. The Company values equity instruments and stock options granted to employees and non-employee directors using the Black-Scholes valuation model. The value of the portion of the award that is ultimately expected to vest is recorded as expense over the requisite service periods.
Basic and Diluted Net Loss per Share of Common Stock	Basic and Diluted Net Loss per Share of Common Stock The Company calculates net loss per common share in accordance with FASB Accounting Standards Codification (“ASC”) ASC Earnings Per Share The following potentially dilutive shares of common stock have not been included in the computation of diluted net loss per share for all periods as the result would be anti-dilutive: December 31, 2018 2017 Warrants to purchase Series C-1 Preferred 14,033 14,033 Warrants to purchase common stock associated with June 2016 Public Offering 4,218,750 4,218,750 Warrants to purchase common stock associated with Solar loan agreement 122,435 122,435 Warrants to purchase common stock associated with March 2018 Public Offering - Series 1 13,198,075 — Warrants to purchase common stock associated with March 2018 Public Offering - Series 2 7,988,175 — Stock options 4,052,913 3,075,994
Segment and Geographic Information	Segment and Geographic Information Operating segments are defined as components of an enterprise (business activity from which it earns revenue and incurs expenses) about which discrete financial information is available and regularly reviewed by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker (“CODM”) is the Chief Executive Officer. The CODM reviews consolidated operating results to make decisions about allocating resources and assessing performance for the entire Company. The Company views its operations and manages its business as one operating segment. All assets of the Company were held in the United States for the years ended December 31, 2018 and 2017. Although all operations are based in the United States, the Company generated a portion of its revenue from R-Pharm outside of the United States. All of the Company's revenue was generated from a non-refundable upfront payment received under a licensing and collaboration arrangement with a partner located in Russia. All sales, including sales outside of the United States, are denominated in United States dollars.
Reclassification of Prior Year Amounts	Reclassification of Prior Year Amounts Certain prior year amounts have been reclassified for consistency with the current year presentation.
Effect of Recent Accounting Pronouncements	Effect of Recent Accounting Pronouncements In February 2016, the FASB issued Accounting Standards Update ("ASU") No. 2016-02, Leases, or ASU 2016-02. The new guidance requires lessees to recognize the assets and liabilities arising from leases on the balance sheet. For public companies, ASU 2016-02 is effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2018, and early adoption is permitted. In July 2018, the FASB issued ASU No. 2018-11, Leases, Targeted Improvements, which provides entities with an additional (and optional) transition method to adopt ASU 2016-02. The Company expects to recognize a right of use asset and corresponding lease liability for the operating lease for its corporate headquarters further disclosed in Note 8. The practical expedients under ASC 842-10-65-1(f) and ASC 842-10-15-37 are also expected to be utilized as part of the implementation and the Company will recognize the cumulative-effect adjustment as of January 1, 2019, the first reporting report in which the Company is applying ASU 2016-02. 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, or ASU 2018-13, which modifies the disclosure requirements on fair value measurements. ASU 2018-13 is effective for us in the first quarter of fiscal 2020, and earlier adoption is permitted. We are currently evaluating the impact of our pending adoption of ASU 2018-13 on our consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
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 all periods as the result would be anti-dilutive: December 31, 2018 2017 Warrants to purchase Series C-1 Preferred 14,033 14,033 Warrants to purchase common stock associated with June 2016 Public Offering 4,218,750 4,218,750 Warrants to purchase common stock associated with Solar loan agreement 122,435 122,435 Warrants to purchase common stock associated with March 2018 Public Offering - Series 1 13,198,075 — Warrants to purchase common stock associated with March 2018 Public Offering - Series 2 7,988,175 — Stock options 4,052,913 3,075,994

Short-term Investments (Tables)

Short-term Investments (Tables)	12 Months Ended
	Dec. 31, 2018
Investments Debt And Equity Securities [Abstract]
Held-to-maturity Securities	The following table summarizes the held-to-maturity securities held at December 31, 2018 (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value As of December 31, 2017 U.S. government securities $ 11,462 $ 74 $ (79 ) $ 11,457 Commercial paper 11,962 — — 11,962 Overnight repurchase agreement 9,000 — — 9,000 Total short-term investments $ 32,424 $ 74 $ (79 ) $ 32,419 Amortized Cost Unrealized Gains Unrealized Losses Fair Value As of December 31, 2018 U.S. government securities 14,946 14 (15 ) 14,945 Commercial paper 8,772 — — 8,772 Overnight repurchase agreement 9,000 — — 9,000 Total short-term investments $ 32,718 14 (15 ) $ 32,717

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2018
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): December 31, 2018 2017 Prepaid research and development services $ 245 $ 384 Prepaid insurance 200 279 Other prepaid expenses 20 62 Other receivable due from R-Pharm — 251 NOL sale receivable (see Note 10) 6,732 — Other current assets 54 91 Total prepaid expenses and other current assets $ 7,251 $ 1,067

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consisted of the following (in thousands): December 31, 2018 2017 Furniture and fixtures $ 406 $ — Computer equipment 73 12 Other 98 — 577 12 Less: accumulated depreciation and amortization (61 ) (8 ) Total property and equipment $ 516 $ 4

Accrued Expense (Tables)

Accrued Expense (Tables)	12 Months Ended
	Dec. 31, 2018
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following (in thousands): December 31, 2018 2017 Accrued research and development expenses $ 587 $ 609 Accrued employee bonus compensation 1,197 763 Employee withholdings 21 29 Other accrued expenses 298 304 Total accrued expenses $ 2,103 $ 1,705

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Lease Payments	Future minimum lease payments for all operating leases as of December 31, 2018 are as follows (in thousands): 2019 498 2020 508 2021 518 2022 529 2023 716 Thereafter 4,203 Total $ 6,972

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Common Stock Reserved For Future Issuances	The Company had reserved shares of common stock for future issuance as follows: December 31, 2018 2017 Outstanding stock options 4,052,913 3,075,994 Outstanding restricted stock units 111,891 64,365 Outstanding Series C-1 Preferred warrants 14,033 14,033 Warrants to purchase common stock associated with June 2016 Public Offering 4,218,750 4,218,750 Warrants to purchase common stock associated with March 2018 Public Offering - Series 1 13,198,075 — Warrants to purchase common stock associated with March 2018 Public Offering - Series 2 7,988,175 — Warrants to purchase common stock associated with Solar loan agreement 122,435 122,435 For possible future issuance under 2014 Equity Incentive Plan (Note 10) 612,018 492,382 For possible future issuance under 2014 Employee Stock Purchase Plan (Note 10) 81,667 83,617 For possible future issuance under 2015 Inducement Plan (Note 10) 5,000 5,000 Total common shares reserved for future issuance 30,404,957 8,076,576

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	Reconciliations of the differences between the benefit for income taxes and income taxes at the statutory U.S. federal income tax rate is as follows (dollars in thousands): 2018 2017 Amount Percent of Pretax Income Amount Percent of Pretax Income Income taxes from continuing operations at statutory rate $ (4,033 ) 21.0 % $ (8,520 ) 34.0 % State income taxes (985 ) 5.1 % (1,075 ) 4.3 % State effect of permanent items (585 ) 3.0 % (112 ) 0.4 % Stock-based compensation 94 (0.5 )% 35 (0.1 )% Deferred rate change 438 (2.3 )% 23,776 (94.9 )% Warrants issuance (2,492 ) 13.0 % (928 ) 3.7 % Other 71 (0.34 )% 828 (3.3 )% NOL sale (3,938 ) 20.5 % — — Increase in valuation allowance 4,694 (24.4 )% (14,004 ) 55.9 % Total income tax benefit $ (6,736 ) 35.1 % $ — — %
Schedule of Deferred Tax Assets and Liabilities	The components of deferred tax assets and liabilities as of December 31, 2018 and 2017 are as follows (in thousands): December 31, 2018 2017 Current deferred tax assets: Accrued expenses $ — $ 182 Stock-based compensation — 1,309 Other — 49 — 1,540 Noncurrent deferred tax assets (liabilities) Accrued expenses 132 — Stock-based compensation 1,911 — Other (31 ) — Net operating loss carryforwards 44,730 40,504 Research and development credits 3,226 3,230 49,968 43,734 Total deferred tax assets 49,968 45,274 Valuation allowances (49,968 ) (45,274 ) Net deferred tax assets $ — $ —
Schedule of Unrecognized Tax Benefits Roll Forward	The following is a tabular reconciliation of the total amounts of unrecognized tax benefits as of December 31, 2018 and 2017 (in thousands): December 31, 2018 2017 Unrecognized tax benefit—January 1 $ 436 $ 623 Additions for tax positions of current period — — Additions for tax positions of prior periods — — Deferred rate change — (187 ) Unrecognized tax benefit—December 31 $ 436 $ 436

Stock-based Compensation (Table

Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Assumptions Used To Estimate Fair Value of Options	The assumptions used to estimate fair value and the resulting grant date fair values are as follows: Employees Non-employee Directors Years Ended December 31, Years Ended December 31, 2018 2017 2018 2017 Weighted average expected volatility 52.31 % 51.38 % 58.65 % 53.86 % Weighted average risk-free interest rate 2.64 % 2.07 % 2.44 % 2.01 % Weighted average expected term (in years) 6.02 6.04 5.28 5.37
Schedule of Share-based Compensation, Stock Options, Activity	The activity for the 2009 Plan, 2014 Plan and 2015 Plan for the years ended December 31, 2018 and 2017 is summarized as follows: Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value ($000) Outstanding — January 1, 2017 1,819,444 $ 7.52 6.98 $ 32 Granted 1,256,770 $ 2.80 Exercised — Forfeited/expired (220 ) $ 9.64 Outstanding — December 31, 2017 3,075,994 $ 5.59 7.23 $ 151 Exercisable — December 31, 2017 1,602,114 $ 7.19 5.78 $ 15 Vested or expected to vest — December 31, 2017 3,075,994 $ 5.59 7.23 $ 151 Outstanding — January 1, 2018 3,075,994 $ 5.59 7.23 $ 151 Granted 1,259,530 $ 1.73 Exercised — Forfeited/expired (282,611 ) $ 5.81 Outstanding — December 31, 2018 4,052,913 $ 4.37 7.23 — Exercisable — December 31, 2018 2,323,907 $ 5.77 6.24 — Vested or expected to vest —December 31, 2018 4,052,913 $ 4.37 7.23 —
Schedule of Restricted Stock Units ("RSU") Activity	Restricted stock unit ("RSU") activity under the 2014 Plan for the year ended December 31, 2018, is summarized as follows: Number of Shares Weighted Average Grant Date Fair Value Per Share Non-vested at December 31, 2017 64,365 $ 2.70 Granted 68,000 1.65 Vested (14,785 ) 2.68 Forfeited (5,689 ) 2.89 Non-vested at December 31, 2018 111,891 $ 2.06
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 statements of operations (in thousands): Years Ended December 31, 2018 2017 Research and development, net $ 519 $ 458 Selling, general and administrative 1,297 1,204 Total stock-based compensation expense $ 1,816 $ 1,662

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured on a Recurring Basis	The following table summarizes the conclusions reached as of December 31, 2018 and 2017 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) December 31, 2017 Cash on deposit $ 1,316 $ 1,316 — — Money market funds 10,153 10,153 — — Total assets $ 11,469 $ 11,469 — — Warrant liability $ 3,872 — — $ 3,872 Total liabilities $ 3,872 $ — — $ 3,872 December 31, 2018 Cash $ 213 $ 213 — — Restricted cash 328 328 — — Money market funds 11,226 11,226 — — Total assets $ 11,767 $ 11,767 — — Warrant liability $ 986 — — $ 986 Total liabilities $ 986 — — $ 986
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): December 31, 2018 Balance - January 1, 2018 $ 3,872 March 2018 Public Offering - Series 1 Warrants 3,480 March 2018 Public Offering - Series 2 Warrants 5,500 Gain adjustment to fair value (11,866 ) Balance - December 31, 2018 $ 986

Description of Business and B_2

Description of Business and Basis of Preparation - Additional Information (Detail) - USD ($)	Sep. 14, 2018	Mar. 08, 2018	Jun. 21, 2016	Dec. 31, 2018	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shelf registration maximum equity offering price	$ 175,000,000
Aggregate amount receivable upon exercise of warrants	53,000,000
Common stock issued, net of expenses (in shares)		17,751,500	9,375,000
Common stock issued, net of expenses				$ 20,437,000	$ 9,954,000
Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Common stock issued, net of expenses (in shares)				18,959,675	4,344,108
Common stock issued, net of expenses				$ 19,000	$ 5,000
Series 1 Warrant
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of warrants issued to purchase common stock (in shares)				115,550
Sales Agreement | Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shelf registration maximum equity offering price	$ 25,000,000
June 2016 Public Offering
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of warrants issued to purchase common stock (in shares)	4,218,750
Exercise price of warrants (in dollars per share)	$ 3		$ 3
March 2018 Public Offering
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of warrants issued to purchase common stock (in shares)		21,301,800
Common stock issued, net of expenses (in shares)		17,751,500
Share price (in dollars per share)		$ 1.69
Common stock issued, net of expenses		$ 27,900,000
March 2018 Public Offering | Series 1 Warrant
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of warrants issued to purchase common stock (in shares)	13,198,075
Exercise price of warrants (in dollars per share)	$ 1.85	$ 1.85
March 2018 Public Offering | Series 2 Warrant
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of warrants issued to purchase common stock (in shares)	7,988,175
Exercise price of warrants (in dollars per share)	$ 2	$ 2

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2013USD ($)	Dec. 31, 2018USD ($)Segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Subsidiary, Sale of Stock [Line Items]
Cash, cash equivalents, and restricted cash		$ 11,767	$ 11,469	$ 35,656
Upfront payment received	$ 1,500
Deferred revenue estimated performance period	70 months
Revenue recognized from upfront payments		$ 257	257
Operating segments (number) | Segment		1
License and Service [Member]
Subsidiary, Sale of Stock [Line Items]
Revenue recognized from upfront payments		$ 300	$ 300
Sales Agreement
Subsidiary, Sale of Stock [Line Items]
Deferred offering costs		$ 200
Collaboration Revenue | R-Pharm, CJSC | Customer Concentration Risk
Subsidiary, Sale of Stock [Line Items]
Percentage of total revenue		100.00%	100.00%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Shares (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	4,052,913	3,075,994
Warrants to purchase Series C-1 Preferred | Warrant liability
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	14,033	14,033
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)	4,218,750	4,218,750
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)	122,435	122,435
March 2018 Public Offering Series 1 [Member] | Warrant liability
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	13,198,075	0
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)	7,988,175	0

Short-term Investments (Details

Short-term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 32,718	$ 32,424
Unrealized Gains	14	74
Unrealized Losses	(15)	(79)
Fair Value	32,717	32,419
Commercial paper
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	8,772	11,962
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	8,772	11,962
Overnight repurchase agreement
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	9,000	9,000
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	9,000	9,000
U.S. government securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	14,946	11,462
Unrealized Gains	14	74
Unrealized Losses	(15)	(79)
Fair Value	$ 14,945	$ 11,457

Short-term Investments - Additi

Short-term Investments - Additional Information (Details) $ in Millions	Dec. 31, 2018USD ($)
Investments Debt And Equity Securities [Abstract]
Held-to-maturity investments with contractual maturities less than one year	$ 32.7

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid research and development services	$ 245	$ 384
Prepaid insurance	200	279
Other prepaid expenses	20	62
Other receivable due from R-Pharm	0	251
NOL sale receivable	6,732	0
Other current assets	54	91
Total prepaid expenses and other current assets	$ 7,251	$ 1,067

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 577	$ 12
Less: accumulated depreciation and amortization	(61)	(8)
Total property and equipment	516	4
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	406	0
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	73	12
Other
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 98	$ 0

Accrued Expense (Details)

Accrued Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Payables And Accruals [Abstract]
Accrued research and development expenses	$ 587	$ 609
Accrued employee bonus compensation	1,197	763
Employee withholdings	21	29
Other accrued expenses	298	304
Total accrued expenses	$ 2,103	$ 1,705

Borrowings - Additional Informa

Borrowings - Additional Information (Details) - USD ($)	Mar. 07, 2019	Sep. 30, 2016
Warrants to purchase common stock associated with Solar loan agreement
Debt Instrument [Line Items]
Number of warrants issued to purchase common stock (in shares)		122,435
Exercise price of warrants (in dollars per share)		$ 3.6754
Warrants issued, expiration period		5 years
6.0% Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Face amount	$ 16,000,000
Date of issuance and sale of notes	Mar. 7, 2019
Interest rate	6.00%
Secured Debt | Term Loan
Debt Instrument [Line Items]
Loan agreement term		48 months
Face amount		$ 15,000,000
Secured Debt | Term Loan | 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 ($)ft²	Jul. 22, 2015USD ($)ft²	Dec. 31, 2018USD ($)Agreement	Dec. 31, 2017USD ($)
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
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. Under the lease, the Company must furnish a security deposit in the form of a standby letter of credit in the amount of $0.3 million, which will be reduced by fifty-five thousand dollars every two years for ten years after the commencement of the lease
Security deposit in the form of a standby letter of credit	$ 300,000
Decrease in security deposit	$ 55,000
Number of additional license agreements | Agreement			2
License agreements fee			$ 2,300,000
Maximum
Commitment And Contingencies [Line Items]
Milestone payments from the Company			19,000,000
Jersey City, New Jersey
Commitment And Contingencies [Line Items]
Area of subleased space (in sqft) | ft²		10,141
Base rent, per month		$ 25,000
Annual increase in base rent (percent)		3.00%
Security deposit paid		$ 100,000
Rent expense			$ 500,000	$ 300,000

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Lease Payments (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Commitments And Contingencies Disclosure [Abstract]
2019	$ 498
2020	508
2021	518
2022	529
2023	716
Thereafter	4,203
Total	$ 6,972

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	Mar. 08, 2018	Sep. 30, 2016	Jun. 21, 2016	Jul. 31, 2006	Dec. 31, 2018	Dec. 31, 2017	Sep. 14, 2018	May 07, 2014
Schedule Of Capitalization Equity [Line Items]
Common stock, par value (in dollars per share)					$ 0.001	$ 0.001
Common stock, shares authorized (in shares)					125,000,000	125,000,000
Common stock, shares issued (in shares)					47,971,989	28,971,651
Common stock, shares outstanding (in shares)					47,971,989	28,971,651
Preferred stock, shares authorized (in shares)					5,000,000	5,000,000		5,000,000
Preferred stock, par value (in dollars per share)					$ 0.001	$ 0.001		$ 0.001
Preferred stock, shares issued (in shares)					0	0
Preferred stock, shares outstanding (in shares)					0	0
Common stock issued, net of expenses (in shares)	17,751,500		9,375,000
Warrant liabilities fair value adjustment					$ (11,866,000)	$ (2,729,000)
Warrant liabilities					$ 1,000,000
Warrants to purchase common stock associated with Solar loan agreement
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)		122,435
Exercise price of warrants (in dollars per share)		$ 3.6754
Warrant expiration period		5 years
June 2016 Public Offering
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)							4,218,750
Exercise price of warrants (in dollars per share)			$ 3				$ 3
Number of shares received per warrant (in shares)			0.45
Warrant expiration period			5 years
March 2018 Public Offering
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)	21,301,800
Common stock issued, net of expenses (in shares)	17,751,500
Warrant liability | June 2016 Public Offering | Maximum
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)			4,218,750
Warrant liability | March 2018 Public Offering | Maximum
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)	21,301,800
Series 1 Warrant
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)					115,550
Proceeds from Warrant Exercises					$ 200,000
warrants expiration	Mar. 14, 2019
Series 1 Warrant | March 2018 Public Offering
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)							13,198,075
Exercise price of warrants (in dollars per share)	$ 1.85						$ 1.85
Number of shares received per warrant (in shares)	0.75
Warrant term	371 days
Series 1 Warrant | March 2018 Public Offering | Maximum
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)	13,313,625
Series 2 Warrant | March 2018 Public Offering
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)							7,988,175
Exercise price of warrants (in dollars per share)	$ 2						$ 2
Number of shares received per warrant (in shares)	0.45
Warrant term	5 years
Series 2 Warrant | March 2018 Public Offering | Maximum
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)	7,988,175
Series C-1 Convertible Preferred Stock [Member]
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)				196,923
Exercise price of warrants (in dollars per share)				$ 3.25
Fair value of warrants				$ 500,000
Derivative Liability					$ 0	$ 0
Common Stock
Schedule Of Capitalization Equity [Line Items]
Number of warrants issued to purchase common stock (in shares)				14,033
Exercise price of warrants (in dollars per share)				$ 45.61

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Detail) - shares	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Common shares reserved for future issuance	30,404,957	8,076,576
2014 Equity Incentive Plan
Class of Stock [Line Items]
Common shares reserved for future issuance	612,018	492,382
2014 Employee Stock Purchase Plan
Class of Stock [Line Items]
Common shares reserved for future issuance	81,667	83,617
2015 Inducement Plan
Class of Stock [Line Items]
Common shares reserved for future issuance	5,000	5,000
Series C1 Preferred Warrants
Class of Stock [Line Items]
Common shares reserved for future issuance	14,033	14,033
June 2016 Public Offering | Warrant liability
Class of Stock [Line Items]
Common shares reserved for future issuance	4,218,750	4,218,750
March 2018 Public Offering | Series 1 Warrant
Class of Stock [Line Items]
Common shares reserved for future issuance	13,198,075	0
March 2018 Public Offering | Series 2 Warrant
Class of Stock [Line Items]
Common shares reserved for future issuance	7,988,175	0
Warrants to purchase common stock associated with Solar loan agreement | Warrant liability
Class of Stock [Line Items]
Common shares reserved for future issuance	122,435	122,435
Stock options
Class of Stock [Line Items]
Common shares reserved for future issuance	4,052,913	3,075,994
Restricted Stock Units
Class of Stock [Line Items]
Common shares reserved for future issuance	111,891	64,365

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	Jan. 03, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Income tax benefit		$ 6,736,000	$ 0
Loss before taxes		$ 19,204,000	$ 25,060,000
Corporate income tax rate		21.00%	34.00%
Temporary expensing for certain business assets and property, percent		100.00%
Maximum deduction percentage of pre-NOL taxable income		80.00%
Unrecognized tax benefits that would impact effective tax rate		$ 0
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit		0
Income tax examination, penalties and interest accrued		$ 0
Maximum
Operating Loss Carryforwards [Line Items]
Corporate income tax rate		21.00%	35.00%
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward		$ 194,900,000	$ 171,500,000
Tax credit carryforward		3,100,000
NOL subject to expiration		171,900,000
NOL subject not to expiration		$ 23,000,000
NOL expiration date		Dec. 31, 2038
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward		$ 150,800,000	$ 166,400,000
State | New Jersey | Subsequent Event
Operating Loss Carryforwards [Line Items]
Cash receipt from the sale of state NOLs	$ 6,700,000

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Amount
Income taxes from continuing operations at statutory rate	$ (4,033)	$ (8,520)
State income taxes	(985)	(1,075)
State effect of permanent items	(585)	(112)
Stock-based compensation	94	35
Deferred rate change	438	23,776
Warrants issuance	(2,492)	(928)
Other	71	828
NOL sale	(3,938)	0
Increase in valuation allowance	4,694	(14,004)
Total income tax benefit	$ (6,736)	$ 0
Percent of Pretax Income
Income taxes from continuing operations at statutory rate	21.00%	34.00%
State income taxes	5.10%	4.30%
State effect of permanent items	3.00%	0.40%
Stock-based compensation	(0.50%)	(0.10%)
Deferred rate change	(2.30%)	(94.90%)
Warrants issuance	13.00%	3.70%
Other	(0.34%)	(3.30%)
NOL sale	20.50%	0.00%
Increase in valuation allowance	(24.40%)	55.90%
Total income tax benefit	35.10%	0.00%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Accrued expenses	$ 0	$ 182
Stock-based compensation	0	1,309
Other	0	49
Current deferred tax assets	0	1,540
Accrued expenses	132	0
Stock-based compensation	1,911	0
Other	(31)	0
Net operating loss carryforwards	44,730	40,504
Research and development credits	3,226	3,230
Noncurrent deferred tax assets (liabilities)	49,968	43,734
Total deferred tax assets	49,968	45,274
Valuation allowances	(49,968)	(45,274)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits	$ 436	$ 623
Additions for tax positions of current period	0	0
Additions for tax positions of prior periods	0	0
Deferred rate change	0	(187)
Unrecognized tax benefits	$ 436	$ 436

Stock-based Compensation - 2009

Stock-based Compensation - 2009 Stock Option Plan (Details) - 2009 Stock Option Plan	12 Months Ended
	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period of options	10 years
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of exercise price	100.00%
Vesting period of options	3 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of exercise price	110.00%
Vesting period of options	4 years

Stock-based Compensation - 2014

Stock-based Compensation - 2014 Equity Incentive Plan (Details) - 2014 Equity Incentive Plan - shares	May 02, 2014	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional awards expected to be granted (in shares)	0
Expiration period of options		10 years
Common stock outstanding percentage	4.00%
Number of shares of common stock for future issuance, board of directors prerogative, increase in period (in shares)	0
Share-based compensation arrangement by share-based payment award, number of additional shares authorized		1,158,866	984,376
Possible future issuance under equity compensation plan (in shares)		612,018
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of options		3 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of options		4 years
Base number of new shares available for future issuance under equity incentive plan (in shares)	1,122,731
Common stock issuable period	10 years

Stock-based Compensation - 2015

Stock-based Compensation - 2015 Inducement Plan (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Mar. 26, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)	1,259,530	1,256,770
2015 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under the plan (in shares)			450,000
Granted (shares)	0
Possible future issuance under equity compensation plan (in shares)	5,000

Stock-based Compensation - Opti

Stock-based Compensation - Option Valuation Method - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted average value of options granted in period (in dollars per share)	$ 0.90	$ 1.39
Aggregate fair value of options granted	$ 1.1	$ 1.8

Stock-based Compensation - Op_2

Stock-based Compensation - Option Valuation Method (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted average expected volatility, employees	52.31%	51.38%
Weighted average expected volatility, non-employees directors	58.65%	53.86%
Weighted average risk-free interest rate, employees	2.64%	2.07%
Weighted average risk-free interest rate, non-employees directors	2.44%	2.01%
Weighted average expected term (in years), employees	6 years 7 days	6 years 14 days
Weighted average expected term (in years), non-employees directors	5 years 3 months 10 days	5 years 4 months 13 days

Stock-based Compensation - Stoc

Stock-based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Beginning balance - Outstanding (shares)	3,075,994	1,819,444
Granted (shares)	1,259,530	1,256,770
Exercised (shares)	0	0
Forfeited/expired (shares)	(282,611)	(220)
Ending balance - Outstanding (shares)	4,052,913	3,075,994	1,819,444
Exercisable (shares)	2,323,907	1,602,114
Vested or expected to vest (shares)	4,052,913	3,075,994
Weighted- Average Exercise Price
Beginning balance - Outstanding (in dollars per share)	$ 5.59	$ 7.52
Granted (in dollars per share)	1.73	2.80
Exercised (in dollars per share)	0	0
Forfeited/expired (in dollars per share)	5.81	9.64
Ending balance - Outstanding (in dollars per share)	4.37	5.59	$ 7.52
Exercisable (in dollars per share)	5.77	7.19
Vested or expected to vest (in dollars per share)	$ 4.37	$ 5.59
Weighted- Average Remaining Contractual Life (in years)
Balance - Outstanding	7 years 2 months 23 days	7 years 2 months 23 days	6 years 11 months 23 days
Exercisable	6 years 2 months 26 days	5 years 9 months 10 days
Vested or expected to vest	7 years 2 months 23 days	7 years 2 months 23 days
Aggregate Intrinsic Value ($000)
Balance - Outstanding	$ 0	$ 151	$ 32
Exercisable	0	15
Vested and expected to vest	$ 0	$ 151

Stock-based Compensation - St_2

Stock-based Compensation - Stock Option Activity - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Total fair value of shares vested during the year	$ 1.8	$ 1.6
Total unrecognized compensation cost related to unvested share-based compensation arrangements	$ 2.1
Total unrecognized compensation cost related to unvested share-based compensation arrangements, recognition period	2 years 1 month 24 days

Stock-based Compensation - Sche

Stock-based Compensation - Schedule of Restricted Stock Units ("RSU") Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares
Weighted Average Grant Date Fair Value Per Share
Total unrecognized compensation cost related to unvested share-based compensation arrangements, recognition period	2 years 1 month 24 days
Restricted Stock Units
Number of Shares
Beginning balance - Outstanding (shares) | shares	64,365
Options granted in period (shares) | shares	68,000
Vested (shares) | shares	(14,785)
Forfeited (shares) | shares	(5,689)
Ending balance - Outstanding (shares) | shares	111,891
Weighted Average Grant Date Fair Value Per Share
Beginning balance - Outstanding (in dollars per share) | $ / shares	$ 2.70
Granted (in dollars per share) | $ / shares	1.65
Vested (in dollars per share) | $ / shares	2.68
Forfeited (in dollars per share) | $ / shares	2.89
Ending balance - Outstanding (in dollars per share) | $ / shares	$ 2.06
Vesting percentage	25.00%
Vesting period of options	4 years
Total unrecognized compensation cost related to unvested RSU share-based compensation | $	$ 0.2
Total unrecognized compensation cost related to unvested share-based compensation arrangements, recognition period	2 years 8 months 23 days

Stock-based Compensation - 20_2

Stock-based Compensation - 2014 Employee Stock Purchase Plan (Details) - 2014 Employee Stock Purchase Plan - shares	May 02, 2014	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
For possible future issuance under employee stock purchase plan (in shares)	47,794
Common stock issuable period	10 years
Common stock outstanding percentage	0.80%
Employee stock purchase plan, number of shares, which might be added to common stock outstanding (in shares)	29,411
Number of shares of common stock for future issuance, board of directors prerogative, increase in period (in shares)	0
Common stock issued through employee stock purchase plan (in shares)		31,361	18,132
Share-based compensation arrangement by share-based payment award, number of additional shares authorized		29,411	29,411
Possible future issuance under equity compensation plan (in shares)		81,667

Stock-based Compensation - Comp

Stock-based Compensation - Compensation Cost (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based compensation expense	$ 1,816,000	$ 1,662,000
Tax benefit from compensation expense	0	0
Cash received from option exercised	$ 0	$ 0

Stock-based Compensation - Expe

Stock-based Compensation - Expense Related to Stock Options (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense related to stock options	$ 1,816	$ 1,662
Research and development, net
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense related to stock options	519	458
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense related to stock options	$ 1,297	$ 1,204

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Measured on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	$ 11,767	$ 11,469
Fair value of financial liabilities	986	3,872
Warrant liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	986	3,872
Cash on deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets		1,316
Money market funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	11,226	10,153
Cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	213
Restricted cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	328
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	11,767	11,469
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) | Cash on deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets		1,316
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	11,226	10,153
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	213
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	328
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) | Cash on deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets		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 Other Observable Inputs (Level 2) | Cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	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
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	986	3,872
Significant Unobservable Inputs (Level 3) | Warrant liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial liabilities	986	3,872
Significant Unobservable Inputs (Level 3) | Cash on deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets		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
Significant Unobservable Inputs (Level 3) | Cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	0
Significant Unobservable Inputs (Level 3) | Restricted cash
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of financial assets	$ 0

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	12 Months Ended
	Dec. 31, 2018USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 3,872
Gain adjustment to fair value	(11,866)
Ending balance	986
Series 1 | Warrant liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
March 2018 Public Offering	3,480
Series 2 | Warrant liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
March 2018 Public Offering	$ 5,500

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)hour	Dec. 31, 2017USD ($)
Compensation And Retirement Disclosure [Abstract]
Work hours per week | hour	20
Employer matching percent	50.00%
Maximum percentage of contributions per employee	6.00%
Vesting period	4 years
Contribution amount | $	$ 0.1	$ 0.1

Subsequent Events - Additional

Subsequent Events - Additional Information (Details)	Mar. 07, 2019USD ($)d$ / shares	Jan. 03, 2019USD ($)	Jan. 01, 2019shares	Dec. 31, 2018shares	Dec. 31, 2017shares
6.0% Convertible Senior Notes due 2025
Subsequent Event [Line Items]
Date of issuance and sale of notes	Mar. 7, 2019
Aggregate principal amount of notes	$ 16,000,000
Interest rate	6.00%
Subsequent Event | 6.0% Convertible Senior Notes due 2025
Subsequent Event [Line Items]
Date of issuance and sale of notes	Mar. 7, 2019
Aggregate principal amount of notes	$ 16,000,000
Purchase price as percentage of principal amount	100.00%
Interest rate	6.00%
Payment terms	The Note will bear interest at a rate of 6.0% per annum payable semiannualy in arrears on March 15 and September 15 of each year, beginning September 15, 2019.
Notes maturity date	Mar. 15, 2025
Notes maturity description	The Note will mature on March 15, 2025, unless earlier converted, redeemed or repurchased.
Conversion terms	holders of the Note may convert their Note 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)	739.0983
Principal amount of notes used as the denominator for conversion into notes	$ 1,000
Initial conversion price of notes | $ / shares	$ 1.35
Conversion rate, number of shares to be issued per $1000 of principal (in shares) after adjustment to certain events	813
Principal amount of notes used as the denominator for conversion into notes after adjustment of certain events	$ 1,000
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%
Subsequent Event | State | New Jersey
Subsequent Event [Line Items]
Cash receipt from sale of NOLs		$ 6,700,000
2014 Equity Incentive Plan
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, number of additional shares authorized | shares				1,158,866	984,376
2014 Equity Incentive Plan | Subsequent Event
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, number of additional shares authorized | shares			1,918,879
2014 Employee Stock Purchase Plan
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, number of additional shares authorized | shares				29,411	29,411
2014 Employee Stock Purchase Plan | Subsequent Event
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, number of additional shares authorized | shares			29,411