scPharmaceuticals (SCPH) 10-Q 12 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Nov. 11, 2019
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	SCPH
Entity Registrant Name	SCPHARMACEUTICALS INC.
Entity Central Index Key	0001604950
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		18,633,530
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock, par value $0.0001
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-38293
Entity Tax Identification Number	46-5184075
Entity Address, Address Line One	2400 District Avenue
Entity Address, Address Line Two	Suite 310
Entity Address, City or Town	Burlington
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01803
City Area Code	617
Local Phone Number	517-0730

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 83,562	$ 89,478
Prepaid expenses	894	1,757
VAT receivable	303	479
Other current assets	128	179
Total current assets	84,887	91,893
Restricted cash	182	182
Property and equipment, net	136	164
Right-of-use lease assets - operating, net	1,264	1,506
Deposits and other assets	197	10
Total assets	86,666	93,755
Current liabilities
Accounts payable	542	587
Accrued expenses	7,169	2,922
Term loan, short term		2,811
Lease obligation - operating, short term	393	353
Total current liabilities	8,104	6,673
Term loan, long term	18,842	6,826
Lease obligation - operating, long term	1,052	1,353
Derivative liability	766
Other liabilities	16	159
Total liabilities	28,780	15,011
Commitments and contingencies (Note 10)
Stockholders’ equity
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued and outstanding
Common stock, $0.0001 par value; 150,000,000 shares authorized as of September 30, 2019; 18,569,289 and 18,629,730 shares issued and outstanding as of December 31, 2018 and September 30, 2019, respectively	2	2
Additional paid-in capital	176,524	175,201
Accumulated deficit	(118,640)	(96,459)
Total stockholders’ equity	57,886	78,744
Total liabilities and stockholders’ equity	$ 86,666	$ 93,755

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001
Common stock, shares authorized	150,000,000
Common stock, shares issued	18,629,730	18,569,289
Common stock, shares outstanding	18,629,730	18,569,289

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating expenses:
Research and development	$ 4,293	$ 3,896	$ 16,314	$ 12,799
General and administrative	1,996	1,945	6,158	11,645
Total operating expenses	6,289	5,841	22,472	24,444
Loss from operations	(6,289)	(5,841)	(22,472)	(24,444)
Other (expense) income	83	(5)	61	(58)
Interest income	397	445	1,350	1,221
Interest expense	(398)	(360)	(1,121)	(1,062)
Net loss and comprehensive loss	$ (6,207)	$ (5,761)	$ (22,182)	$ (24,343)
Net loss per share — basic and diluted	$ (0.33)	$ (0.31)	$ (1.19)	$ (1.31)
Weighted average common shares outstanding — basic and diluted	18,584,327	18,569,289	18,580,192	18,551,690

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance at Dec. 31, 2017	$ 105,997	$ 2	$ 173,011	$ (67,016)
Beginning Balance, Shares at Dec. 31, 2017		18,534,240
Net loss	(8,732)			(8,732)
Issuance of common stock upon exercise of stock options	56		56
Issuance of common stock upon exercise of stock options, Shares		7,606
Vesting of restricted stock	1		1
Vesting of restricted stock, Shares		366
Stock-based compensation	622		622
Ending Balance at Mar. 31, 2018	97,944	$ 2	173,690	(75,748)
Ending Balance, Shares at Mar. 31, 2018		18,542,212
Beginning Balance at Dec. 31, 2017	105,997	$ 2	173,011	(67,016)
Beginning Balance, Shares at Dec. 31, 2017		18,534,240
Net loss	(24,343)
Ending Balance at Sep. 30, 2018	83,390	$ 2	174,747	(91,359)
Ending Balance, Shares at Sep. 30, 2018		18,569,289
Beginning Balance at Mar. 31, 2018	97,944	$ 2	173,690	(75,748)
Beginning Balance, Shares at Mar. 31, 2018		18,542,212
Net loss	(9,850)			(9,850)
Issuance of common stock upon exercise of stock options	2		2
Issuance of common stock upon exercise of stock options, Shares		26,955
Vesting of restricted stock, Shares		122
Stock-based compensation	497		497
Ending Balance at Jun. 30, 2018	88,593	$ 2	174,189	(85,598)
Ending Balance, Shares at Jun. 30, 2018		18,569,289
Net loss	(5,761)			(5,761)
Offering costs	(5)		(5)
Stock-based compensation	563		563
Ending Balance at Sep. 30, 2018	83,390	$ 2	174,747	(91,359)
Ending Balance, Shares at Sep. 30, 2018		18,569,289
Beginning Balance at Dec. 31, 2018	78,744	$ 2	175,201	(96,459)
Beginning Balance, Shares at Dec. 31, 2018		18,569,289
Net loss	(8,719)			(8,719)
Issuance of common stock upon exercise of stock options	18		18
Issuance of common stock upon exercise of stock options, Shares		11,141
Stock-based compensation	355		355
Ending Balance at Mar. 31, 2019	70,398	$ 2	175,574	(105,178)
Ending Balance, Shares at Mar. 31, 2019		18,580,430
Beginning Balance at Dec. 31, 2018	78,744	$ 2	175,201	(96,459)
Beginning Balance, Shares at Dec. 31, 2018		18,569,289
Net loss	$ (22,182)
Issuance of common stock upon exercise of stock options, Shares	20,141
Ending Balance at Sep. 30, 2019	$ 57,886	$ 2	176,524	(118,640)
Ending Balance, Shares at Sep. 30, 2019		18,629,730
Beginning Balance at Mar. 31, 2019	70,398	$ 2	175,574	(105,178)
Beginning Balance, Shares at Mar. 31, 2019		18,580,430
Net loss	(7,255)			(7,255)
Stock-based compensation	326		326
Ending Balance at Jun. 30, 2019	63,469	$ 2	175,900	(112,433)
Ending Balance, Shares at Jun. 30, 2019		18,580,430
Net loss	(6,207)			(6,207)
Issuance of common stock under at-the-market offering, net of issuance costs (Note 9)	256		256
Issuance of common stock under at-the-market offering, net of issuance costs, Shares		40,300
Issuance of common stock upon exercise of stock options	35		35
Issuance of common stock upon exercise of stock options, Shares		9,000
Stock-based compensation	333		333
Ending Balance at Sep. 30, 2019	$ 57,886	$ 2	$ 176,524	$ (118,640)
Ending Balance, Shares at Sep. 30, 2019		18,629,730

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities
Net loss	$ (22,182,000)	$ (24,343,000)
Adjustments to reconcile net loss to cash used in operating activities
Depreciation expense	29,000	29,000
Amortization expense - right-of-use leased assets - operating	241,000	218,000
Stock-based compensation	1,014,000	1,682,000
Non-cash interest expense	260,000	278,000
Fair value adjustment to derivative liability	3,000
Changes in operating assets and liabilities
Prepaid expenses and other assets	1,088,000	51,000
Accounts payable, accrued expenses and other liabilities	3,940,000	(926,000)
Net cash used in operating activities	(15,607,000)	(23,011,000)
Cash flows from investing activities
Purchases of property and equipment		(41,000)
Net cash used in investing activities		(41,000)
Cash flows from financing activities
Costs related to initial public offering		(5,000)
Proceeds from at-the-market offering, net of commissions	259,000
At-the-market offering costs	(189,000)
Proceeds from term loan, net of costs	9,568,000
Proceeds from the exercise of vested stock options	53,000	58,000
Net cash provided by financing activities	9,691,000	53,000
Net decrease in cash, cash equivalents and restricted cash	(5,916,000)	(22,999,000)
Cash, cash equivalents and restricted cash at beginning of period	89,660,000	118,480,000
Cash, cash equivalents and restricted cash at end of period	83,744,000	95,481,000
Supplemental cash flow information
Interest paid	925,000	738,000
Taxes paid	296,000	283,000
Supplemental non-cash information
Acquisition of right-of-use leased assets - operating, net of disposal		$ 26,000
Issuance of derivative in connection with modification of term loan	763,000
Transfer of issuance costs from other noncurrent assets to equity	$ 3,000

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Description of Business scPharmaceuticals LLC was formed as a Limited Liability Company under the laws of the State of Delaware on February 19, 2013. On March 24, 2014, scPharmaceuticals LLC was converted to a Delaware corporation and changed its name to scPharmaceuticals Inc. (“the Company”). The Company is a pharmaceutical company focused on developing and commercializing products that have the potential to optimize the delivery of infused therapies, advance patient care and reduce healthcare costs. The Company’s proprietary platform is designed to enable the subcutaneous administration of therapies that have previously been limited to intravenous, or IV, delivery. The Company’s headquarters and primary place of business is Burlington, Massachusetts. In January 2019, following a Type C meeting with the Food and Drug Administration, management implemented a restructuring plan to reduce operating costs and better align its workforce with the needs of its business. The Company recorded a charge of $1.4 million during the nine months ended September 30, 2019 related to the restructuring plan, which included severance, benefits and related costs. The Company recorded $966,000 and $426,000 in research and development expenses and general and administrative expenses related to the restructuring, respectively. The Company paid $1.3 million of these costs during the nine months ended September 30, 2019 and expects to pay $18,000 in the fourth quarter of 2019. The remainder of the restructuring charge consists of a non-cash charge of $70,000 related to the modification of stock options (Note 6). As of September 30, 2019, the Company had a balance of $18,000 in accrued expenses related to severance benefits, and related costs associated with the restructuring plan. Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and have been prepared on a basis which assumes that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The condensed consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiary, scPharmaceuticals Securities Corporation. Certain information and disclosures normally included in financial statements in accordance with U.S. GAAP have been condensed or omitted. Accordingly, these condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements and related notes for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 21, 2019. The Company has determined that it operates in one segment. The accompanying condensed consolidated balance sheet as of September 30, 2019, the condensed consolidated statements of operations and comprehensive loss and stockholders’ equity for the three and nine months ended September 30, 2018 and 2019 and condensed consolidated statements of cash flows for the nine months ended September 30, 2018 and 2019 are unaudited. The unaudited condensed consolidated financial statements have been prepared on a basis consistent with that used to prepare the Company’s audited annual financial statements and include, in the opinion of management, adjustments, consisting of normal recurring items, necessary for the fair statement of the condensed consolidated financial statements. The operating results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results expected for the full year ending December 31, 2019.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reported periods. Actual results could differ from those estimates. Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consists of bank deposits, certificates of deposit and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. As of September 30, 2019, the Company classified $182,000 as restricted cash related to a letter of credit issued as a security deposit in connection with the Company’s lease of its corporate office facilities (Note 10). Cash, cash equivalents and restricted cash consist of the following: December 31, 2018 September 30, 2019 Cash and cash equivalents $ 89,478 $ 83,562 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 89,660 $ 83,744 Derivative Liability In September 2019, the Company entered into a new loan and security agreement with Solar Capital Ltd. and Silicon Valley Bank (the “2019 Loan Agreement”) to refinance the Company’s 2017 Loan Agreement (Note 8). In connection with the 2019 Loan Agreement, the Company also entered into an exit agreement with Solar Capital Ltd. and Silicon Valley Bank (the “Exit Agreement”). The Exit Agreement provides for a payment to the lenders in the amount of 4% of the loan commitment, or $800,000, upon the occurrence of an exit event, as defined in the Exit Agreement. The Company classifies the exit payment obligation as a liability on its balance sheet because it represents a contingent payment obligation that is not clearly and closely related to the host instrument and meets the definition of a derivative. The derivative liability was initially recorded at fair value upon execution of the 2019 Loan Agreement and is subsequently remeasured to fair value at each reporting date. Changes in the fair value of the derivative liability are recognized as a component of other income (expense), net in the statement of operations and comprehensive loss. Changes in the fair value of the derivative liability will continue to be recognized until an exit event occurs. Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use (“ROU”) lease assets, current portion of lease obligations, and long term lease obligations on the Company’s balance sheets. ROU lease assets represent the Company’s right to use an underlying asset for the lease term and lease obligations represent the Company’s obligation to make lease payments arising from the lease. Operating ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The ROU lease asset excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Income Taxes The Company accounts for income taxes in accordance with the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) 740, Income Taxes. The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions. The tax benefits recorded are based on a determination of whether and how much of a tax benefit taken by the Company in its tax filings or positions is “more likely than not” to be realized following resolution of any uncertainty related to the tax benefit, assuming that the matter in question will be raised by the tax authorities. Potential interest and penalties associated with such uncertain tax positions are recorded as a component of income tax expense. At September 30, 2019, the Company had no such accruals. Recently Issued Accounting Standards In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820) (“ASU 2018-13”). ASU 2018-13 modifies fair value disclosure requirements, specifically around level transfers and valuation of Level 3 assets and liabilities. ASU 2018-13 is effective for financial statements issued for annual and interim periods beginning after December 15, 2019 for all entities. Early adoption of all or part of ASU No. 2018-13 is permitted. The Company does not expect ASU 2018-13 to have a material impact on its financial statements.

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Loss per Share	3. Net Loss per Share Net Loss per Share Attributable to Common Stockholders The following table sets forth the computation of basic and diluted net loss per share of common stock (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, 2018 2019 2018 2019 Net loss and comprehensive loss $ (5,761 ) $ (6,207 ) $ (24,343 ) $ (22,182 ) Weighted-average shares used in computing net loss per share 18,569,289 18,584,327 18,551,690 18,580,192 Net loss per share, basic and diluted $ (0.31 ) $ (0.33 ) $ (1.31 ) $ (1.19 ) The Company’s potentially dilutive securities, which include stock options and unvested restricted stock, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect. Three Months Ended September 30, Nine Months Ended September 30, 2018 2019 2018 2019 Stock options to purchase common stock 1,746,287 1,424,018 1,746,287 1,424,018 Unvested restricted stock — 160,900 — 160,900 Total 1,746,287 1,584,918 1,746,287 1,584,918

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Property and Equipment	4. Property and Equipment Purchased property and equipment consist of the following (dollars in thousands): ESTIMATED USEFUL LIFE December 31, 2018 September 30, 2019 Office equipment 5 years $ 10 $ 10 Office furniture 7 years 116 116 Computer equipment 3 years 8 8 Leasehold improvements Life of lease 95 95 229 229 Less: Accumulated depreciation (65 ) (93 ) Property and equipment, net $ 164 $ 136 Depreciation expense for the three months ended September 30, 2018 and September 30, 2019 was $10,000 and $10,000, respectively. Depreciation expense for the nine months ended September 30, 2018 and September 30, 2019 was $29,000 and $29,000, respectively. Leased property and equipment consist of the following (dollars in thousands): ESTIMATED USEFUL LIFE December 31, 2018 September 30, 2019 Right-of-use lease assets - operating Lease term $ 2,024 $ 2,024 Less: Accumulated amortization (518 ) (760 ) Right-of-use lease assets - operating, net $ 1,506 $ 1,264 Amortization expense for the three months ended September 30, 2018 and September 30, 2019 was $74,000 and $82,000, respectively. Amortization expense for the nine months ended September 30, 2018 and September 30, 2019 was $218,000 and $241,000, respectively.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2019
Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consist of (in thousands): December 31, 2018 September 30, 2019 Contract research and development $ 1,492 $ 4,146 Unrecoverable component costs — 1,668 Employee compensation and related costs 727 923 Consulting and professional service fees 356 338 State taxes 165 36 Severance costs 133 18 Other 49 40 Total accrued expenses $ 2,922 $ 7,169

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	6. Stock-Based Compensation Stock Options The Company’s 2017 Stock Option and Incentive Plan (the “2017 Stock Plan”) became effective in November 2017, upon the closing of the Company’s initial public offering and will expire in October 2027. Under the 2017 Stock Plan, the Company may grant incentive stock options, non-statutory stock options, restricted stock awards, restricted stock units (“RSUs”) and other stock-based awards. The Company’s 2014 Stock Incentive Plan (the “2014 Stock Plan”) was terminated in November 2017 upon the completion of the Company’s initial public offering and no further options were granted under the 2014 Stock Plan. At September 30, 2019, there were 830,962 options outstanding under the 2014 Plan. As of September 30, 2019, there were 3,166,868 shares of the Company’s common stock authorized for issuance under the 2017 Stock Plan, including 252,707 options that have been forfeited from the 2014 Plan. At September 30, 2019, there were 2,412,912 options available for issuance under the 2017 Stock Plan, 593,056 options outstanding and 160,900 restricted stock units outstanding. Awards granted under the 2017 Plan have a term of ten years. Vesting of awards under the 2017 Stock Plan is determined by the board of directors, but is generally over one to four-year terms. The fair value of options at date of grant was estimated using the Black-Scholes option-pricing model with the following assumptions: Nine Months Ended September 30, 2018 2019 Risk-free interest rate 2.42%-2.86% 1.61%-2.51% Expected dividend yield 0% 0% Expected life 5.5-7.0 years 5.5-6.1 years Expected volatility 76%-86% 72%-74% Weighted-average grant date fair value $ 7.57 $ 2.17 The following table summarizes information about stock option activity during the nine months ended September 30, 2019 (in thousands, except share and per share data): NUMBER OF SHARES WEIGHTED- AVERAGE EXERCISE PRICE WEIGHTED- AVERAGE REMAINING CONTRACTUAL TERM AGGREGATE INTRINSIC VALUE Outstanding, December 31, 2018 1,588,306 $ 6.75 Granted 145,022 3.34 Exercised (20,141 ) 2.62 Forfeited (289,169 ) 8.54 Outstanding, September 30, 2019 1,424,018 $ 6.09 7.84 $ 1,842 Vested and exercisable, September 30, 2019 854,952 $ 6.20 7.45 $ 1,024 Vested and expected to vest, September 30, 2019 1,308,083 $ 6.15 7.76 $ 1,661 The following table summarizes information about RSU activity during the nine months ended September 30, 2019: RSUs AVERAGE GRANT DATE FAIR VALUE (IN DOLLARS PER SHARE) Outstanding, December 31, 2018 — $ — Granted 160,900 1.43 Vested — — Forfeited — — RSUs outstanding at September 30, 2019 160,900 $ 1.43 Unrecognized compensation expense related to unvested options as of September 30, 2019 was $1.8 million and will be recognized over the remaining vesting periods of the underlying awards. The weighted-average period over which such compensation is expected to be recognized is 1.9 years. Unrecognized compensation expense related to unvested RSUs as of September 30, 2019 was $116,000 and will be recognized over the remaining vesting periods of the underlying awards. The weighted-average period over which such compensation is expected to be recognized is 1.3 years. During The Company recorded stock-based compensation expense in the following expense categories of its accompanying condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2018 and 2019 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2019 2018 2019 Research and development $ 154 $ 75 $ 394 $ 215 General and administrative 409 258 1,288 799 Total $ 563 $ 333 $ 1,682 $ 1,014

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	7. Fair Value of Financial Instruments The Financial Accounting Standards Board (“FASB”) Accounting Standard Codification (“ASC”) Topic, Fair Value Measurements and Disclosures (“ASC 820”), Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and observable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying values of the Company’s cash and restricted cash, prepaid expenses, value added tax, or VAT, receivable and deposits approximate their fair values due to their short-term nature. The carrying value of the Company’s loan payable was considered a reasonable estimate of fair value because the Company’s interest rate is near current market rates for instruments with similar characteristics. The following table summarizes the Company’s assets and liabilities as of September 30, 2019 that are measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): TOTAL Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash equivalents $ 62,549 $ 62,549 $ — $ — Total $ 62,549 $ 62,549 $ — $ — Liabilities: Derivative liability $ 766 $ — $ — $ 766 Total $ 766 $ — $ — $ 766 The fair value of the derivative liability recognized in connection with the Company’s 2019 Loan Agreement (Note 8) was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The fair value of the derivative liability was determined using the probability-weighted expected return method (“PWERM”), which considered as inputs the timing and probability of occurrence of an exit event, the amount of the payment, and the risk-free discount rate reflecting the expected risk profile for each of the potential settlement scenarios.

Term Loan

Term Loan	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Term Loan	8. Term Loan In May 2017, the Company entered into a loan and security agreement (the “2017 Loan Agreement”), with Solar Capital Ltd. and Silicon Valley Bank for $10.0 million. The 2017 Loan Agreement had a maturity date of May 1, 2021. Debt issuance costs for the 2017 Loan Agreement were to be amortized to interest expense over the remaining term of the 2017 Loan Agreement using the effective-interest method. The interest rate under the 2017 Loan Agreement was LIBOR plus 8.45%. The initial interest-only period was until November 30, 2018, followed by a 30-month principal and interest period. The First Amendment to the Loan and Security Agreement, entered into in November 2018, extended the interest-only period through May 2019. The Third Amendment to the Loan and Security Agreement, entered into in May 2019, extended the interest-only period through August 2019, with the ability to further extend the interest only period to November 2019. Pursuant to the 2017 Loan Agreement, the Company provided a first priority security interest in all existing and after-acquired assets, excluding intellectual property, owned by the Company. For the three and nine months ended September 30, 2019, the Company recorded $53,000 and $169,000, respectively, related to the amortization of debt discount associated with the 2017 Loan Agreement. For the three and nine months ended September 30, 2018 the Company recorded $68,000 and $212,000, respectively, related to the amortization of debt discount associated with the 2017 Loan Agreement. The 2017 Loan Agreement allowed the Company to voluntarily prepay all (but not less than all) of the outstanding principal at any time. A prepayment premium of 1% would be assessed on the outstanding principal. A final payment fee of $250,000 was due upon the earlier to occur of the maturity date or prepayment of such borrowings. The final payment fee was increased to $325,000 in the First Amendment to the 2017 Loan Agreement. For the three and nine months ended September 30, 2019, the Company recorded $23,000 and $80,000, respectively, related to the amortization of the final payment fee associated with the 2017 Loan Agreement. For the three and nine months ended September 30, 2018, the Company recorded $22,000 and $66,000, respectively, related to the amortization of the final payment fee associated with the 2017 Loan Agreement. In September 2019, the Company paid off the outstanding balance of the 2017 Loan Agreement, including accrued interest, The payoff was treated as a modification of the debt. The interest rate under the 2019 Loan Agreement is the higher of (i) LIBOR plus 7.95% or (ii) 10.18% and there is an interest-only period until September 30, 2021. The rate at September 30, 2019 was 10.18%. Pursuant to the 2019 Loan Agreement, the Company provided a first priority security interest in all existing and after-acquired assets owned by the Company, including all intellectual property and subject to certain exceptions. The Company entered into the Exit Agreement in connection with the 2019 Loan Agreement which provides for an aggregate payment of 4% of the loan commitment, or $800,000, to the lenders upon the occurrence of an exit event. The Company concluded that the exit payment obligation met the definition of a derivative that was required to be accounted for as a separate unit of accounting. The Company recorded the issuance-date fair value of the derivative liability of $763,000 as a debt discount and as a derivative liability in the Company’s balance sheet. As of September 30, 2019, unpaid borrowings under the 2019 Loan Agreement totaled $20.0 million. For the three and nine months ended September 30, 2019, the Company recorded $5,000 related to the amortization of debt discount associated with the 2019 Loan Agreement. The 2019 Loan Agreement allows the Company to voluntarily prepay all (but not less than all) of the outstanding principal at any time. A prepayment premium of 3% or 1% through the one-year anniversary and the two-year anniversary, respectively, would be assessed on the outstanding principal. After the two-year anniversary, a 0.5% prepayment premium would be assessed on the outstanding principal. A final payment fee of $500,000 is due upon the earlier to occur of the maturity date or prepayment of such borrowings. For the three and nine months ended September 30, 2019, the Company recorded $6,000 related to the amortization of the final payment fee associated with the 2019 Loan Agreement. In an event of default under the 2019 Loan Agreement, the interest rate will be increased by 5% and the balance under the loan may become immediately due and payable at the option of the lenders. The 2019 Loan Agreement includes restrictions on, among other things, the Company’s ability to incur additional indebtedness, change the name or location of the Company’s business, merge with or acquire other entities, pay dividends or make other distributions to holders of its capital stock, make certain investments, engage in transactions with affiliates, create liens, sell assets or pay subordinated debt. Total term loan and unamortized debt discount balances are as follows (in thousands): September 30, 2019 Face value $ 20,000 Less: discount (1,158 ) Total $ 18,842 Less: current portion — Total $ 18,842 As of September 30, 2019, future principal payments due under the 2019 Loan Agreement are as follows (in thousands): Year ended: December 31, 2021 $ 2,500 December 31, 2022 10,000 December 31, 2023 7,500 Total $ 20,000

Stockholders_ Equity

Stockholders’ Equity	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Stockholders’ Equity	9. At-the-Market Issuance Sales Agreement On August 23, 2019, the Company entered into an Open Market Sale Agreement SM Subject to the terms and conditions of the ATM Agreement, Jefferies will use its commercially reasonable efforts to sell the ATM Shares, based upon instructions from the Company, consistent with its normal trading and sales practices. The Company will pay Jefferies a commission equal to 3.0% of the gross sales proceeds of such ATM Shares. During the three months ended September 30, 2019, the Company sold a total of 40,300 ATM Shares under the ATM Agreement, in the open market, at an average gross selling price of $6.63 per share for net proceeds of $259,000. During the three months ended September 30, 2019, the Company incurred $189,000 of legal, accounting and other costs to establish and activate the ATM program. The Company charged $3,000 of these costs against additional paid in capital upon issuance of shares during the three months ended September 30,2019.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and Contingencies Operating Leases The Company leases office facilities and equipment under long-term, non-cancelable operating lease agreements. The leases expire at various dates through 2022 and do not include renewal options. Certain leases provide for increases in future minimum annual rental payments as defined in the lease agreements. The leases generally also include real estate taxes and common area maintenance (“CAM”) charges in the annual rental payments. Pursuant to the terms of its lease agreement for the Company’s headquarters, the Company obtained a letter of credit in the amount of approximately $182,000 as security on the lease obligation. The letter of credit is listed as restricted cash on the Company’s consolidated balance sheets. Short-term leases are leases having a term of twelve months or less. The Company recognizes short-term leases on a straight-line basis and does not record a related lease asset or liability for such leases. The following is a maturity analysis of the annual undiscounted cash flows of the operating lease liabilities as of September 30, 2019 (in thousands): Year ended: December 31, 2019 $ 131 December 31, 2020 528 December 31, 2021 537 December 31, 2022 496 Total minimum lease payments 1,692 Less imputed interest (247 ) Total $ 1,445 Nine Months Ended September 30, 2018 2019 Lease cost: Operating lease cost $ 348 $ 368 Short-term lease cost 6 6 Sublease income (26 ) (38 ) Total lease cost $ 328 $ 336 Other information Cash paid for amounts included in the measurement of lease liabilities $ 302 $ 384 Operating cash flows from operating leases $ 55 $ (21 ) Weighted-average remaining lease term - operating leases 4.2 years 3.2 years Weighted-average discount rate - operating leases 10.1 % 10.1 % In February 2018, the Company signed a sublease agreement for its facility located in Lexington, Massachusetts. The lease commenced on April 1, 2018 and has an initial term of three years with an extension term through December 2022. Research and Development Agreements As part of the Company’s research and development efforts, the Company enters into research and development agreements with unrelated companies. These agreements contain varying terms and provisions which include fees and milestones to be paid by the Company. Some of these agreements also contain provisions which require the Company to make payments for exclusivity in the development of products in the area of loop diuretics. Contingencies The Company follows subtopic 450-20 of the FASB Accounting Standards Codification to report accounting for contingencies. Certain conditions may exist as of the date the financial statements are issued, which may result in a loss to the Company but which will only be resolved when one or more future events occur or fail to occur. The Company assesses such contingent liabilities, and such assessment inherently involves an exercise of judgment. If the assessment of a contingency indicates that it is probable that a material loss has been incurred and the amount of the liability can be estimated, then the estimated liability would be accrued in the Company’s financial statements. If the assessment indicates that a potential material loss contingency is not probable but is reasonably possible, or is probable but cannot be estimated, then the nature of the contingent liability, and an estimate of the range of possible losses, if determinable and material, would be disclosed. Loss contingencies considered remote are generally not disclosed unless they involve guarantees, in which case the guarantees would be disclosed. Due to the discontinuation of use of the sc2Wear Infusor, the Company has received notice of termination costs related to the program. The Company has accrued all costs for which it either believes it is contractually liable or for which the Company has negotiated settlement agreements in good faith. However, certain of the Company’s vendors have claimed or billed for additional costs for which the Company believes it is not obligated. At this time, the Company estimates that additional termination costs, if any, will be immaterial to the Company’s financial statements.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reported periods. Actual results could differ from those estimates.
Cash Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consists of bank deposits, certificates of deposit and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. As of September 30, 2019, the Company classified $182,000 as restricted cash related to a letter of credit issued as a security deposit in connection with the Company’s lease of its corporate office facilities (Note 10). Cash, cash equivalents and restricted cash consist of the following: December 31, 2018 September 30, 2019 Cash and cash equivalents $ 89,478 $ 83,562 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 89,660 $ 83,744
Derivative Liability	Derivative Liability In September 2019, the Company entered into a new loan and security agreement with Solar Capital Ltd. and Silicon Valley Bank (the “2019 Loan Agreement”) to refinance the Company’s 2017 Loan Agreement (Note 8). In connection with the 2019 Loan Agreement, the Company also entered into an exit agreement with Solar Capital Ltd. and Silicon Valley Bank (the “Exit Agreement”). The Exit Agreement provides for a payment to the lenders in the amount of 4% of the loan commitment, or $800,000, upon the occurrence of an exit event, as defined in the Exit Agreement. The Company classifies the exit payment obligation as a liability on its balance sheet because it represents a contingent payment obligation that is not clearly and closely related to the host instrument and meets the definition of a derivative. The derivative liability was initially recorded at fair value upon execution of the 2019 Loan Agreement and is subsequently remeasured to fair value at each reporting date. Changes in the fair value of the derivative liability are recognized as a component of other income (expense), net in the statement of operations and comprehensive loss. Changes in the fair value of the derivative liability will continue to be recognized until an exit event occurs.
Leases	Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use (“ROU”) lease assets, current portion of lease obligations, and long term lease obligations on the Company’s balance sheets. ROU lease assets represent the Company’s right to use an underlying asset for the lease term and lease obligations represent the Company’s obligation to make lease payments arising from the lease. Operating ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The ROU lease asset excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) 740, Income Taxes. The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions. The tax benefits recorded are based on a determination of whether and how much of a tax benefit taken by the Company in its tax filings or positions is “more likely than not” to be realized following resolution of any uncertainty related to the tax benefit, assuming that the matter in question will be raised by the tax authorities. Potential interest and penalties associated with such uncertain tax positions are recorded as a component of income tax expense. At September 30, 2019, the Company had no such accruals.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820) (“ASU 2018-13”). ASU 2018-13 modifies fair value disclosure requirements, specifically around level transfers and valuation of Level 3 assets and liabilities. ASU 2018-13 is effective for financial statements issued for annual and interim periods beginning after December 15, 2019 for all entities. Early adoption of all or part of ASU No. 2018-13 is permitted. The Company does not expect ASU 2018-13 to have a material impact on its financial statements.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Schedule of Cash, Cash Equivalents and Restricted Cash	As of September 30, 2019, the Company classified $182,000 as restricted cash related to a letter of credit issued as a security deposit in connection with the Company’s lease of its corporate office facilities (Note 10). Cash, cash equivalents and restricted cash consist of the following: December 31, 2018 September 30, 2019 Cash and cash equivalents $ 89,478 $ 83,562 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 89,660 $ 83,744

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss Per Share of Common Stock	The following table sets forth the computation of basic and diluted net loss per share of common stock (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, 2018 2019 2018 2019 Net loss and comprehensive loss $ (5,761 ) $ (6,207 ) $ (24,343 ) $ (22,182 ) Weighted-average shares used in computing net loss per share 18,569,289 18,584,327 18,551,690 18,580,192 Net loss per share, basic and diluted $ (0.31 ) $ (0.33 ) $ (1.31 ) $ (1.19 )
Schedule of Antidilutive Securities Excluded from Computation of Net Loss Per Share	The Company’s potentially dilutive securities, which include stock options and unvested restricted stock, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect. Three Months Ended September 30, Nine Months Ended September 30, 2018 2019 2018 2019 Stock options to purchase common stock 1,746,287 1,424,018 1,746,287 1,424,018 Unvested restricted stock — 160,900 — 160,900 Total 1,746,287 1,584,918 1,746,287 1,584,918

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Schedule of Purchased Property and Equipment	Purchased property and equipment consist of the following (dollars in thousands): ESTIMATED USEFUL LIFE December 31, 2018 September 30, 2019 Office equipment 5 years $ 10 $ 10 Office furniture 7 years 116 116 Computer equipment 3 years 8 8 Leasehold improvements Life of lease 95 95 229 229 Less: Accumulated depreciation (65 ) (93 ) Property and equipment, net $ 164 $ 136
Schedule of Leased Property and Equipment	Leased property and equipment consist of the following (dollars in thousands): ESTIMATED USEFUL LIFE December 31, 2018 September 30, 2019 Right-of-use lease assets - operating Lease term $ 2,024 $ 2,024 Less: Accumulated amortization (518 ) (760 ) Right-of-use lease assets - operating, net $ 1,506 $ 1,264

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2019
Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of (in thousands): December 31, 2018 September 30, 2019 Contract research and development $ 1,492 $ 4,146 Unrecoverable component costs — 1,668 Employee compensation and related costs 727 923 Consulting and professional service fees 356 338 State taxes 165 36 Severance costs 133 18 Other 49 40 Total accrued expenses $ 2,922 $ 7,169

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Estimated Fair Value of Options Valuation Assumptions	The fair value of options at date of grant was estimated using the Black-Scholes option-pricing model with the following assumptions: Nine Months Ended September 30, 2018 2019 Risk-free interest rate 2.42%-2.86% 1.61%-2.51% Expected dividend yield 0% 0% Expected life 5.5-7.0 years 5.5-6.1 years Expected volatility 76%-86% 72%-74% Weighted-average grant date fair value $ 7.57 $ 2.17
Summary of Information about Stock Option Activity	The following table summarizes information about stock option activity during the nine months ended September 30, 2019 (in thousands, except share and per share data): NUMBER OF SHARES WEIGHTED- AVERAGE EXERCISE PRICE WEIGHTED- AVERAGE REMAINING CONTRACTUAL TERM AGGREGATE INTRINSIC VALUE Outstanding, December 31, 2018 1,588,306 $ 6.75 Granted 145,022 3.34 Exercised (20,141 ) 2.62 Forfeited (289,169 ) 8.54 Outstanding, September 30, 2019 1,424,018 $ 6.09 7.84 $ 1,842 Vested and exercisable, September 30, 2019 854,952 $ 6.20 7.45 $ 1,024 Vested and expected to vest, September 30, 2019 1,308,083 $ 6.15 7.76 $ 1,661
Schedule of RSU Activity	The following table summarizes information about RSU activity during the nine months ended September 30, 2019: RSUs AVERAGE GRANT DATE FAIR VALUE (IN DOLLARS PER SHARE) Outstanding, December 31, 2018 — $ — Granted 160,900 1.43 Vested — — Forfeited — — RSUs outstanding at September 30, 2019 160,900 $ 1.43
Summary of Stock-Based Compensation Expense	The Company recorded stock-based compensation expense in the following expense categories of its accompanying condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2018 and 2019 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2019 2018 2019 Research and development $ 154 $ 75 $ 394 $ 215 General and administrative 409 258 1,288 799 Total $ 563 $ 333 $ 1,682 $ 1,014

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table summarizes the Company’s assets and liabilities as of September 30, 2019 that are measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): TOTAL Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash equivalents $ 62,549 $ 62,549 $ — $ — Total $ 62,549 $ 62,549 $ — $ — Liabilities: Derivative liability $ 766 $ — $ — $ 766 Total $ 766 $ — $ — $ 766

Term Loan (Tables)

Term Loan (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Total Term Loan and Unamortized Debt Discount	Total term loan and unamortized debt discount balances are as follows (in thousands): September 30, 2019 Face value $ 20,000 Less: discount (1,158 ) Total $ 18,842 Less: current portion — Total $ 18,842
Schedule of Future Principal Payments Due	As of September 30, 2019, future principal payments due under the 2019 Loan Agreement are as follows (in thousands): Year ended: December 31, 2021 $ 2,500 December 31, 2022 10,000 December 31, 2023 7,500 Total $ 20,000

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating Lease Liabilities	The following is a maturity analysis of the annual undiscounted cash flows of the operating lease liabilities as of September 30, 2019 (in thousands): Year ended: December 31, 2019 $ 131 December 31, 2020 528 December 31, 2021 537 December 31, 2022 496 Total minimum lease payments 1,692 Less imputed interest (247 ) Total $ 1,445
Schedule of Lease Cost and Other Information of Operating Lease Liabilities	Nine Months Ended September 30, 2018 2019 Lease cost: Operating lease cost $ 348 $ 368 Short-term lease cost 6 6 Sublease income (26 ) (38 ) Total lease cost $ 328 $ 336 Other information Cash paid for amounts included in the measurement of lease liabilities $ 302 $ 384 Operating cash flows from operating leases $ 55 $ (21 ) Weighted-average remaining lease term - operating leases 4.2 years 3.2 years Weighted-average discount rate - operating leases 10.1 % 10.1 %

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended
	Dec. 31, 2019	Sep. 30, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Restructuring charges		$ 1,400,000
Restructuring cost paid		1,300,000
Non-cash charge related to modification of stock options		70,000
Severance, benefits, and related costs		18,000
Scenario, Forecast
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Restructuring cost paid	$ 18,000
Research and Development
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Restructuring charges		966,000
General and Administrative
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Restructuring charges		$ 426,000

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Schedule Of Accounting Policies [Line Items]
Restricted cash	$ 182,000	$ 182,000
Potential interest and penalties associated with uncertain tax positions, accruals	$ 0
Solar Capital Ltd. and Silicon Valley Bank | 2019 Loan Agreement
Schedule Of Accounting Policies [Line Items]
Exit fee, percentage	4.00%
Exit fee	$ 800,000
Letter of Credit
Schedule Of Accounting Policies [Line Items]
Restricted cash	$ 182,000

Significant Accounting Polici_5

Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 83,562	$ 89,478
Restricted cash	182	182
Cash, cash equivalents and restricted cash	$ 83,744	$ 89,660	$ 95,481	$ 118,480

Net Loss per Share - Computatio

Net Loss per Share - Computation of Basic and Diluted Net Loss Per Share of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net loss and comprehensive loss	$ (6,207)	$ (5,761)	$ (22,182)	$ (24,343)
Weighted-average shares used in computing net loss per share	18,584,327	18,569,289	18,580,192	18,551,690
Net loss per share, basic and diluted	$ (0.33)	$ (0.31)	$ (1.19)	$ (1.31)

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	1,584,918	1,746,287	1,584,918	1,746,287
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	1,424,018	1,746,287	1,424,018	1,746,287
Unvested Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	160,900		160,900

Property and Equipment - Schedu

Property and Equipment - Schedule of Purchased Property and Equipment (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	Lease term
Property and equipment, gross	$ 229	$ 229
Less: Accumulated depreciation	(93)	(65)
Property and equipment, net	$ 136	164
Office Equipment
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	5 years
Property and equipment, gross	$ 10	10
Office Furniture
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	7 years
Property and equipment, gross	$ 116	116
Computer Equipment
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	3 years
Property and equipment, gross	$ 8	8
Leasehold Improvements
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	Life of lease
Property and equipment, gross	$ 95	$ 95

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Property Plant And Equipment [Abstract]
Depreciation expense	$ 10,000	$ 10,000	$ 29,000	$ 29,000
Amortization expense	$ 82,000	$ 74,000	$ 241,000	$ 218,000

Property and Equipment - Sche_2

Property and Equipment - Schedule of Leased Property and Equipment (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Right-of-use lease assets - operating	$ 2,024	$ 2,024
Less: Accumulated amortization	(760)	(518)
Right-of-use lease assets - operating, net	$ 1,264	$ 1,506
ESTIMATED USEFUL LIFE	Lease term

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accruals [Abstract]
Contract research and development	$ 4,146	$ 1,492
Unrecoverable component costs	1,668
Employee compensation and related costs	923	727
Consulting and professional service fees	338	356
State taxes	36	165
Severance costs	18	133
Other	40	49
Total accrued expenses	$ 7,169	$ 2,922

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional options granted	145,022
Stock option, number of shares outstanding	1,424,018	1,588,306
Unrecognized compensation expense	$ 1,800,000
Recognition period (in years)	1 year 10 months 24 days
Weighted average exercise price for vested options	$ 8.41
Incremental stock-based compensation expense	$ 70,000
Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards vesting term	1 year
Number of options vested	55,677
Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards vesting term	2 years
Number of options vested	85,432
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of restricted stock units outstanding	160,900	0
Unrecognized compensation expense	$ 116,000
Recognition period (in years)	1 year 3 months 18 days
2017 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option and incentive plan effective date	Nov. 30, 2017
Stock option and incentive plan expiration date	Oct. 31, 2027
Stock option, number of shares outstanding	593,056
Number of common shares authorized for issuance	3,166,868
Stock options, available for issuance	2,412,912
Term of awards granted	10 years
2017 Stock Plan | Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of restricted stock units outstanding	160,900
2017 Stock Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards vesting term	1 year
2017 Stock Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Awards vesting term	4 years
2014 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option and incentive plan expiration date	Nov. 30, 2017
Additional options granted	0
Stock option, number of shares outstanding	830,962
Number of options forfeited	252,707

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Estimated Fair Value of Options Valuation Assumptions (Details) - $ / shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	1.61%	2.42%
Risk-free interest rate, maximum	2.51%	2.86%
Expected dividend yield	0.00%	0.00%
Expected volatility, minimum	72.00%	76.00%
Expected volatility, maximum	74.00%	86.00%
Weighted-average grant date fair value	$ 2.17	$ 7.57
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	5 years 6 months	5 years 6 months
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	6 years 3 days	7 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Information about Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2019
NUMBER OF SHARES
Number of shares outstanding, beginning balance	1,588,306
Additional options granted	145,022
Number of shares exercised	(20,141)
Number of shares forfeited	(289,169)
Number of shares outstanding, ending balance	1,424,018
Vested and exercisable, ending balance	854,952
Vested and expected to vest, ending balance	1,308,083
WEIGHTED-AVERAGE EXERCISE PRICE
Weighted average exercise prices, outstanding beginning balance	$ 6.75
Weighted average exercise prices, granted	3.34
Weighted average exercise prices, exercised	2.62
Weighted average exercise prices, forfeited	8.54
Weighted average exercise prices, outstanding ending balance	6.09
Weighted average exercise prices, vested and exercisable ending balance	6.20
Weighted average exercise prices, vested and expected to vest ending balance	$ 6.15
WEIGHTED-AVERAGE REMAINING CONTRACTUAL TERM
Weighted average remaining contractual term, outstanding	7 years 10 months 2 days
Weighted average remaining contractual term, vested and exercisable	7 years 5 months 12 days
Weighted average remaining contractual term, vested and expected to vest	7 years 9 months 3 days
AGGREGATE INTRINSIC VALUE
Aggregate intrinsic value, outstanding ending balance	$ 1,842
Aggregate intrinsic value, vested and exercisable ending balance	1,024
Aggregate intrinsic value, vested and expected to vest ending balance	$ 1,661

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of RSU Activity (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs Outstanding, December 31, 2018 | shares	0
RSUs Granted | shares	160,900
RSUs outstanding at September 30, 2019 | shares	160,900
AVERAGE GRANT DATE FAIR VALUE, Outstanding, December 31, 2018 | $ / shares	$ 0
AVERAGE GRANT DATE FAIR VALUE, Granted | $ / shares	1.43
AVERAGE GRANT DATE FAIR VALUE, RSUs outstanding at September 30, 2019 | $ / shares	$ 1.43

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 333	$ 563	$ 1,014	$ 1,682
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	75	154	215	394
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 258	$ 409	$ 799	$ 1,288

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring $ in Thousands	Sep. 30, 2019USD ($)
Assets:
Cash equivalents	$ 62,549
Total	62,549
Liabilities:
Derivative liability	766
Total	766
Quoted Prices in Active Markets (Level 1) [Member]
Assets:
Cash equivalents	62,549
Total	62,549
Significant Unobservable Inputs (Level 3) [Member]
Liabilities:
Derivative liability	766
Total	$ 766

Term Loan - Additional Informat

Term Loan - Additional Information (Details) - Solar Capital Ltd. and Silicon Valley Bank - USD ($)	1 Months Ended			3 Months Ended		9 Months Ended
	Sep. 30, 2019	Nov. 30, 2018	May 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
2017 Loan Agreement
Debt Instrument [Line Items]
Loan and security agreement, amount			$ 10,000,000
Loan agreement, maturity date			May 1, 2021
Amortization of debt discount				$ 53,000	$ 68,000	$ 169,000	$ 212,000
Prepayment premium thereafter						1.00%
Final payment fee						$ 250,000
Amortization of final payment fee				23,000	$ 22,000	80,000	$ 66,000
2017 Loan Agreement | Libor
Debt Instrument [Line Items]
Basis spread on variable base rate			8.45%
First Amendment to Loan and Security Agreement
Debt Instrument [Line Items]
Final payment fee		$ 325,000
2019 Loan Agreement
Debt Instrument [Line Items]
Loan and security agreement, amount	$ 20,000,000			20,000,000		20,000,000
Loan agreement, maturity date	Sep. 17, 2023
Amortization of debt discount				5,000		5,000
Final payment fee						500,000
Amortization of final payment fee				$ 6,000		$ 6,000
Debt instrument, interest rate terms						The interest rate under the 2019 Loan Agreement is the higher of (i) LIBOR plus 7.95% or (ii) 10.18%
Debt instrument, effective interest rate	10.18%			10.18%		10.18%
Exit fee, percentage						4.00%
Exit fee						$ 800,000
Derivative liability recorded against exit fee obligation	$ 763,000			$ 763,000		763,000
Unpaid borrowings	$ 20,000,000			$ 20,000,000		$ 20,000,000
Prepayment premium percentage after year two						0.50%
Increase in interest rate on default						5.00%
2019 Loan Agreement | Minimum
Debt Instrument [Line Items]
Interest rate, minimum	10.18%			10.18%		10.18%
Prepayment premium percentage						1.00%
2019 Loan Agreement | Maximum
Debt Instrument [Line Items]
Prepayment premium percentage						3.00%
2019 Loan Agreement | Libor
Debt Instrument [Line Items]
Basis spread on variable base rate						7.95%

Term Loan - Schedule of Total T

Term Loan - Schedule of Total Term Loan and Unamortized Debt Discount (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Less: current portion		$ (2,811)
Term loan, long term	$ 18,842	$ 6,826
2019 Loan Agreement | Solar Capital Ltd. and Silicon Valley Bank
Debt Instrument [Line Items]
Face value	20,000
Less: discount	(1,158)
Total	18,842
Term loan, long term	$ 18,842

Term Loan - Schedule of Future

Term Loan - Schedule of Future Principal Payments Due (Details) - 2019 Loan Agreement - Solar Capital Ltd. and Silicon Valley Bank $ in Thousands	Sep. 30, 2019USD ($)
Debt Instrument [Line Items]
December 31, 2021	$ 2,500
December 31, 2022	10,000
December 31, 2023	7,500
Total	$ 20,000

Stockholders Equity - Additiona

Stockholders Equity - Additional Information (Details) - USD ($)	Aug. 23, 2019	Sep. 30, 2019	Sep. 30, 2019
Stockholders Equity Note [Line Items]
Common stock, par value		$ 0.0001	$ 0.0001
Stock issuance cost			$ 189,000
Common Stock
Stockholders Equity Note [Line Items]
Number of shares sold		40,300
ATM Agreement | Legal Accounting and Other Costs
Stockholders Equity Note [Line Items]
Stock issuance cost		$ 189,000
ATM Agreement | Additional Paid-in Capital | Legal Accounting and Other Costs
Stockholders Equity Note [Line Items]
Stock issuance cost		$ 3,000
ATM Agreement | Jefferies | Common Stock
Stockholders Equity Note [Line Items]
Common stock, par value	$ 0.0001
Percentage of commission on gross sales proceeds	3.00%
Number of shares sold		40,300
Selling price per share		$ 6.63	$ 6.63
Net proceeds from sale of shares		$ 259,000
ATM Agreement | Jefferies | Common Stock | Maximum
Stockholders Equity Note [Line Items]
Aggregate offering price	$ 15,000,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	1 Months Ended	9 Months Ended
	Feb. 28, 2018	Sep. 30, 2019	Dec. 31, 2018
Commitments And Contingencies [Line Items]
Operating leases expire		2022
Restricted cash		$ 182,000	$ 182,000
Short-term lease asset		1,264,000	1,506,000
Short-term lease liability		393,000	$ 353,000
Operating sublease term	3 years
Short-term Leases Recognized on Straight-line Basis
Commitments And Contingencies [Line Items]
Short-term lease asset		0
Short-term lease liability		0
Letter of Credit
Commitments And Contingencies [Line Items]
Restricted cash		182,000
Letter of Credit | Lease Agreement Require Standby Letter of Credit
Commitments And Contingencies [Line Items]
Restricted cash		$ 182,000

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019USD ($)
Year ended:
December 31, 2019	$ 131
December 31, 2020	528
December 31, 2021	537
December 31, 2022	496
Total minimum lease payments	1,692
Less imputed interest	(247)
Total	$ 1,445

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Lease Cost and Other Information of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Lease cost:
Operating lease cost	$ 368	$ 348
Short-term lease cost	6	6
Sublease income	(38)	(26)
Total lease cost	336	328
Other information
Cash paid for amounts included in the measurement of lease liabilities	384	302
Operating cash flows from operating leases	$ (21)	$ 55
Weighted-average remaining lease term - operating leases	3 years 2 months 12 days	4 years 2 months 12 days
Weighted-average discount rate - operating leases	10.10%	10.10%