scPharmaceuticals (SCPH) 10-Q 13 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Aug. 11, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
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 Interactive Data Current	Yes
Title of 12(b) Security	Common stock, par value $0.0001
Security Exchange Name	NASDAQ
Entity File Number	001-38293
Entity Incorporation, State or Country Code	DE
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
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		27,319,959

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 78,860	$ 72,624
Short term investments	40,469
Prepaid expenses	2,897	2,619
VAT receivable	298	310
Other current assets	12	94
Total current assets	122,536	75,647
Restricted cash	182	182
Property and equipment, net	110	127
Right-of-use lease assets - operating, net	1,002	1,179
Deposits and other assets	89	148
Total assets	123,919	77,283
Current liabilities
Accounts payable	770	1,142
Accrued expenses	4,724	3,688
Lease obligation - operating, short term	435	407
Total current liabilities	5,929	5,237
Term loan, long term	19,076	18,915
Lease obligation - operating, long term	717	943
Derivative liability		765
Other liabilities	138	58
Total liabilities	25,860	25,918
Commitments and contingencies (Note 11)
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 June 30, 2020; 19,418,955 and 27,287,997 shares issued and outstanding as of December 31, 2019 and June 30, 2020, respectively	3	2
Additional paid-in capital	242,898	180,818
Accumulated deficit	(144,842)	(129,455)
Total stockholders’ equity	98,059	51,365
Total liabilities and stockholders’ equity	$ 123,919	$ 77,283

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
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	27,287,997	19,418,955
Common stock, shares outstanding	27,287,997	19,418,955

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating expenses:
Research and development	$ 5,139	$ 5,496	$ 9,285	$ 12,020
General and administrative	2,537	1,839	5,040	4,162
Total operating expenses	7,676	7,335	14,325	16,182
Loss from operations	(7,676)	(7,335)	(14,325)	(16,182)
Other expense	(1)	(14)	(32)	(22)
Interest income	21	463	245	953
Interest expense	(639)	(369)	(1,275)	(723)
Net loss and comprehensive loss	$ (8,295)	$ (7,255)	$ (15,387)	$ (15,974)
Net loss per share — basic and diluted	$ (0.36)	$ (0.39)	$ (0.71)	$ (0.86)
Weighted average common shares outstanding — basic and diluted	23,355,418	18,580,430	21,786,946	18,578,091

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	At The Market Offering	Underwritten Public Offering	Common Stock	Common StockAt The Market Offering	Common StockUnderwritten Public Offering	Additional Paid-in Capital	Additional Paid-in CapitalAt The Market Offering	Additional Paid-in CapitalUnderwritten Public Offering	Accumulated Deficit
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	(15,974)
Ending Balance at Jun. 30, 2019	63,469			$ 2			175,900			(112,433)
Ending Balance, Shares at Jun. 30, 2019				18,580,430
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
Beginning Balance at Dec. 31, 2019	51,365			$ 2			180,818			(129,455)
Beginning Balance, Shares at Dec. 31, 2019				19,418,955
Net loss	(7,092)									(7,092)
Issuance of common stock, net of commissions and issuance costs		$ 10,253						$ 10,253
Issuance of common stock net of commissions and issuance costs, Shares					1,502,892
Issuance of common stock upon exercise of stock options	154						154
Issuance of common stock upon exercise of stock options, Shares				30,143
Vesting of restricted stock	(84)						(84)
Vesting of restricted stock, Shares				29,890
Stock-based compensation	508						508
Ending Balance at Mar. 31, 2020	55,104			$ 2			191,649			(136,547)
Ending Balance, Shares at Mar. 31, 2020				20,981,880
Beginning Balance at Dec. 31, 2019	51,365			$ 2			180,818			(129,455)
Beginning Balance, Shares at Dec. 31, 2019				19,418,955
Net loss	$ (15,387)
Issuance of common stock upon exercise of stock options, Shares	115,671
Ending Balance at Jun. 30, 2020	$ 98,059			$ 3			242,898			(144,842)
Ending Balance, Shares at Jun. 30, 2020				27,287,997
Beginning Balance at Mar. 31, 2020	55,104			$ 2			191,649			(136,547)
Beginning Balance, Shares at Mar. 31, 2020				20,981,880
Net loss	(8,295)									(8,295)
Issuance of common stock, net of commissions and issuance costs			$ 50,148			$ 1			$ 50,147
Issuance of common stock net of commissions and issuance costs, Shares						6,220,589
Issuance of common stock upon exercise of stock options	561						561
Issuance of common stock upon exercise of stock options, Shares				85,528
Vesting of restricted stock	(80)						(80)
Stock-based compensation	621						621
Ending Balance at Jun. 30, 2020	$ 98,059			$ 3			$ 242,898			$ (144,842)
Ending Balance, Shares at Jun. 30, 2020				27,287,997

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities
Net loss	$ (15,387,000)	$ (15,974,000)
Adjustments to reconcile net loss to cash used in operating activities
Depreciation expense	17,000	19,000
Amortization expense - right-of-use leased assets - operating	177,000	159,000
Accretion of discount on investments	(1,000)
Stock-based compensation	1,129,000	681,000
Non-cash interest expense	246,000	173,000
Fair value adjustment to derivative liability	30,000
Changes in operating assets and liabilities
Prepaid expenses and other assets	(259,000)	107,000
Accounts payable, accrued expenses and other liabilities	343,000	4,806,000
Net cash used in operating activities	(13,705,000)	(10,029,000)
Cash flows from investing activities
Purchases of short term investments	(40,469,000)
Net cash used in investing activities	(40,469,000)
Cash flows from financing activities
Proceeds from common stock offering, net	50,191,000
Proceeds from at-the-market offering, net	10,388,000
Proceeds from the exercise of vested stock options	715,000	18,000
Payment of term loan exit fee	(800,000)
Settlements of restricted stock units for tax withholding obligations	(84,000)
Net cash provided by financing activities	60,410,000	18,000
Net (decrease) increase in cash, cash equivalents and restricted cash	6,236,000	(10,011,000)
Cash, cash equivalents and restricted cash at beginning of period	72,806,000	89,660,000
Cash, cash equivalents and restricted cash at end of period	79,042,000	79,649,000
Supplemental cash flow information
Interest paid	1,436,000	608,000
Taxes paid	$ 144,000	$ 256,000

Description of Business and Bas

Description of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2020
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 strategy is designed to enable the subcutaneous administration of therapies that have previously been limited to intravenous (“IV”) delivery. The Company’s headquarters and primary place of business is Burlington, Massachusetts. 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, 2019 included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on March 24, 2020. The Company has determined that it operates in one segment. The accompanying condensed consolidated balance sheet as of June 30, 2020, the condensed consolidated statements of operations and comprehensive loss and stockholders’ equity for the three and six months ended June 30, 2019 and 2020 and condensed consolidated statements of cash flows for the six months ended June 30, 2019 and 2020 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 six months ended June 30, 2020 are not necessarily indicative of the results expected for the full year ending December 31, 2020. Liquidity As of June 30, 2020, the Company had an accumulated deficit of approximately $144.8 million. As of June 30, 2020, the Company had cash, cash equivalents, restricted cash, and marketable securities of $119.5 million. The Company believes that its existing cash, cash equivalents, restricted cash and marketable securities will be sufficient to meet its cash commitments for at least the next 12 months after the date that the interim condensed consolidated financial statements are issued.

Significant Accounting Policies

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2020
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 June 30, 2020, 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 11). Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, 2019 June 30, 2020 Cash and cash equivalents $ 72,624 $ 78,860 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 72,806 $ 79,042 Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and available-for-sale securities. The Company maintains its cash and cash equivalent balances with high-quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s marketable securities consist of United States Treasury and mortgage-backed securities. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to hold a minimum rating, thereby reducing credit risk exposure. Investments The Company invests excess cash balances in United States Treasury and mortgage-backed securities. The Company determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company reports available-for-sale investments at fair value at each balance sheet date and includes any unrealized gains and losses in accumulated other comprehensive income (loss), a component of stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense). If any adjustment to fair value reflects a decline in the value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is “other than temporary,” including the intention to sell and, if so, marks the investment to market through a charge to the Company’s consolidated statements of operations and comprehensive loss. 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 June 30, 2020, 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. The Company adopted ASU 2018-13 on January 1, 2020 and there has not been any impact to its financial statements.

Net Loss per Share

Net Loss per Share	6 Months Ended
	Jun. 30, 2020
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 June 30, Six Months Ended June 30, 2019 2020 2019 2020 Net loss and comprehensive loss $ (7,255 ) $ (8,295 ) $ (15,974 ) $ (15,387 ) Weighted-average shares used in computing net loss per share 18,580,430 23,355,418 18,578,091 21,786,946 Net loss per share, basic and diluted $ (0.39 ) $ (0.36 ) $ (0.86 ) $ (0.71 ) The Company’s potentially dilutive securities, which include stock options and unvested restricted stock units, 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 June 30, Six Months Ended June 30, 2019 2020 2019 2020 Stock options to purchase common stock 1,430,788 2,029,843 1,430,788 2,029,843 Unvested restricted stock units 160,900 80,450 160,900 80,450 Total 1,591,688 2,110,293 1,591,688 2,110,293

Investments

Investments	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
Investments	4. Investments Cash in excess of the Company’s immediate requirements is invested in accordance with the Company’s investment policy that primarily seeks to maintain adequate liquidity and preserve capital. The following table summarizes the Company’s investments, by category, as of June 30, 2020 (in thousands): Investments - Current: June 30, 2020 Debt securities - available-for-sale $ 40,469 Total $ 40,469 A summary of the Company’s available-for-sale classified investments as of June 30, 2020 consisted of the following (in thousands): At June 30, 2020 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value United States Treasury securities $ 35,973 $ - $ - $ 35,973 Mortgage-backed securities 4,496 - - 4,496 Total $ 40,469 $ - $ - $ 40,469 The amortized cost and fair value of the Company’s available-for-sale investments, by contract maturity, as of June 30, 2020 consisted of the following (in thousands): Amortized Cost Fair Value Due in one year or less $ 40,469 $ 40,469 Total $ 40,469 $ 40,469

Property and Equipment

Property and Equipment	6 Months Ended
	Jun. 30, 2020
Property Plant And Equipment [Abstract]
Property and Equipment	5. Property and Equipment Purchased property and equipment consist of the following (dollars in thousands): ESTIMATED USEFUL LIFE December 31, 2019 June 30, 2020 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 (102 ) (119 ) Property and equipment, net $ 127 $ 110 Depreciation expense for the three months ended June 30, 2019 and June 30, 2020 was $9,000 and $9,000, respectively. Depreciation expense for the six months ended June 30, 2019 and June 30, 2020 was $19,000 and $17,000, respectively.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2020
Accruals [Abstract]
Accrued Expenses	6. Accrued Expenses Accrued expenses consist of the following (in thousands): December 31, 2019 June 30, 2020 Contract research and development $ 2,001 $ 2,937 Employee compensation and related costs 1,250 1,315 Consulting and professional service fees 296 364 Interest 91 85 State taxes 49 20 Other 1 3 Total accrued expenses $ 3,688 $ 4,724

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	7. 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 June 30, 2020, there were 703,636 options outstanding under the 2014 Stock Plan. As of June 30, 2020, there were 3,894,270 shares of the Company’s common stock authorized for issuance under the 2017 Stock Plan, including 265,203 options that have been forfeited from the 2014 Stock Plan. At June 30, 2020, there were 2,466,174 options available for issuance under the 2017 Stock Plan, 1,326,207 options outstanding and 80,450 RSUs outstanding. Awards granted under the 2017 Stock 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: Six Months Ended June 30, 2019 2020 Risk-free interest rate 1.85%-2.51% 0.41% - 1.71% Expected dividend yield 0% 0% Expected life 5.5-6.0 years 5.5-6.6 years Expected volatility 73%-74% 72%-75% Weighted-average grant date fair value $ 2.14 $ 4.06 The following table summarizes information about stock option activity during the six months ended June 30, 2020 (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, 2019 1,439,518 $ 6.09 Granted 763,702 6.32 Exercised (115,671 ) 6.18 Forfeited (57,706 ) 9.97 Outstanding, June 30, 2020 2,029,843 $ 6.06 8.08 $ 4,128 Vested and exercisable, June 30, 2020 956,575 $ 5.69 7.00 $ 2,435 Vested and expected to vest, June 30, 2020 1,669,947 $ 6.01 7.80 $ 3,605 Of the options granted in the six months ended June 30, 2020, 226,110 were performance-based options. Vesting of these performance-based options is contingent on the occurrence of certain regulatory and commercial milestones. The Company is recognizing the expense as straight-line over the expected performance achievement term. The following table summarizes information about RSU activity during the six months ended June 30, 2020: RSUs AVERAGE GRANT DATE FAIR VALUE (IN DOLLARS PER SHARE) Outstanding, December 31, 2019 160,900 $ 3.25 Granted — — Vested (80,450 ) 3.25 Forfeited — — RSUs outstanding at June 30, 2020 80,450 $ 3.25 The number of RSUs vested includes shares of common stock withheld on behalf of employees to satisfy the minimum statutory tax withholding requirements. On June 30, 2020, 42,250 RSUs vested as a result of a regulatory milestone. 31,962 common shares were issued on July 2, 2020 related to the vesting event. Unrecognized compensation expense related to unvested options as of June 30, 2020 was $2.6 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 2.0 years. Unrecognized compensation expense related to unvested RSUs as of June 30, 2020 was $177,000 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 0.6 years. 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 six months ended June 30, 2019 and 2020 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2020 2019 2020 Research and development $ 72 $ 177 $ 140 $ 321 General and administrative 254 444 541 808 Total $ 326 $ 621 $ 681 $ 1,129

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	8. 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 as of June 30, 2020 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 $ 78,165 $ 78,165 $ — $ — Total cash equivalents 78,165 78,165 — — United States Treasury securities 35,973 35,973 — — Mortgage-backed securities 4,496 — 4,496 — Investments 40,469 35,973 4,496 — Total $ 118,634 $ 114,138 $ 4,496 $ —

Term Loan

Term Loan	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Term Loan	9. 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 (together, the “Lenders”), 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 the London Inter-bank Offered Rate (“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 six months ended June 30, 2019, the Company recorded $66,000 and $116,000, 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 six months ended June 30, 2019, the Company recorded $27,000 and $57,000, respectively, related to the amortization of the final payment fee associated with the 2017 Loan Agreement. In September 2019, the Company replaced the 2017 Loan Agreement with a new $20.0 million term loan with the Lenders (the “2019 Loan Agreement”). The restructured four-year term loan facility allows for an expansion of the 2017 Loan Agreement. Some of the proceeds from the 2019 Loan Agreement were used to pay off the 2017 Loan Agreement including the final fee of $325,000. The 2019 Loan Agreement extends the term of the credit facility until September 17, 2023. The payoff of the 2017 Loan Agreement was treated as a modification of the debt. Debt issuance costs for the 2019 Loan Agreement, including unamortized issuance costs for the 2017 Loan Agreement, will be amortized to interest expense over the remaining term of the 2019 Loan Agreement using the effective-interest method. 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 June 30, 2020 was 10.18%. Pursuant to the 2019 Loan Agreement, the Company provided a first priority security interest in substantially all of the Company’s assets, including intellectual property, subject to certain exceptions. The Company entered into an 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 “Exit Fee). 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. The derivative liability is re-measured at each balance sheet date and any changes in estimated fair value is recorded as other income (expense). The Company paid the Exit Fee during the six months ended June 30, 2020 in conjunction with the Company’s public offering, which was deemed to be an exit event pursuant to the Exit Agreement (Note 10). Prior to the public offering, the Company recorded $30,000 in non-cash expense as a fair value adjustment to the derivative liability in 2020. As of June 30, 2020, unpaid borrowings under the 2019 Loan Agreement totaled $20.0 million. For the three and six months ended June 30, 2020, the Company recorded $85,000 and $166,000, respectively, 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 six months ended June 30, 2020, the Company recorded $40,000 and $80,000, respectively, 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): June 30, 2020 Face value $ 20,000 Less: discount (924 ) Total $ 19,076 Less: current portion - Total $ 19,076 As of June 30, 2020, 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	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Stockholders' Equity	10. Stockholders’ Equity At-the-Market Issuance Sales Agreement On August 23, 2019, the Company entered into an Open Market Sale Agreement SM During the three months ended March 31, 2020, the Company sold a total of 1,502,892 ATM Shares under the ATM Agreement, in the open market, at a weighted average gross selling price of $7.13 per share for net proceeds of $10.4 million, which completed the program. The Company charged $135,000 in costs related to establish and activate the program against additional paid in capital upon issuance of shares in 2020. Sale of Common Stock In May 2020, the Company completed an underwritten public offering of 5,780,347 shares of its common stock (the “2020 Offering Shares”), pursuant to the Registration Statement. The 2020 Offering Shares were sold at an offering price of $8.65 per share, resulting in net proceeds of $46.6 million, after deducting underwriting discounts, commissions and offering expenses. In addition, the underwriters of the offering were granted the option for a period of 30 days to purchase up to an additional 867,052 shares of common stock at $8.65 per share. In June 2020, the underwriters exercised their option and purchased an additional 440,242 shares of common stock at $8.65 per share, resulting in additional net proceeds to the Company of $3.6 million, after deducting underwriting discounts, commissions and offering expenses.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	11 . 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 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 June 30, 2020 (in thousands): Year ended: December 31, 2020 $ 266 December 31, 2021 537 December 31, 2022 496 Total minimum lease payments 1,299 Less imputed interest (147 ) Total $ 1,152 Six Months Ended June 30, 2019 2020 Lease cost: Operating lease cost $ 246 $ 243 Short-term lease cost 4 - Sublease income (25 ) (25 ) Total lease cost $ 225 $ 218 Other information Cash paid for amounts included in the measurement of lease liabilities $ 254 $ 267 Operating cash flows from operating leases $ (13 ) $ (20 ) Weighted-average remaining lease term - operating leases 3.4 years 2.4 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. In February 2020, the sublease was extended until December 31, 2022. Research and Development Agreements As part of the Company’s research and development efforts, the Company enters into research and development agreements with certain 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)	6 Months Ended
	Jun. 30, 2020
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 June 30, 2020, 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 11). Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, 2019 June 30, 2020 Cash and cash equivalents $ 72,624 $ 78,860 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 72,806 $ 79,042
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and available-for-sale securities. The Company maintains its cash and cash equivalent balances with high-quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s marketable securities consist of United States Treasury and mortgage-backed securities. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to hold a minimum rating, thereby reducing credit risk exposure.
Investments	Investments The Company invests excess cash balances in United States Treasury and mortgage-backed securities. The Company determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company reports available-for-sale investments at fair value at each balance sheet date and includes any unrealized gains and losses in accumulated other comprehensive income (loss), a component of stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense). If any adjustment to fair value reflects a decline in the value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is “other than temporary,” including the intention to sell and, if so, marks the investment to market through a charge to the Company’s consolidated statements of operations and comprehensive loss.
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 June 30, 2020, 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. The Company adopted ASU 2018-13 on January 1, 2020 and there has not been any impact to its financial statements.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Schedule of Cash, Cash Equivalents and Restricted Cash	As of June 30, 2020, 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 11). Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, 2019 June 30, 2020 Cash and cash equivalents $ 72,624 $ 78,860 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 72,806 $ 79,042

Net Loss per Share (Tables)

Net Loss per Share (Tables)	6 Months Ended
	Jun. 30, 2020
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 June 30, Six Months Ended June 30, 2019 2020 2019 2020 Net loss and comprehensive loss $ (7,255 ) $ (8,295 ) $ (15,974 ) $ (15,387 ) Weighted-average shares used in computing net loss per share 18,580,430 23,355,418 18,578,091 21,786,946 Net loss per share, basic and diluted $ (0.39 ) $ (0.36 ) $ (0.86 ) $ (0.71 )
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 units, 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 June 30, Six Months Ended June 30, 2019 2020 2019 2020 Stock options to purchase common stock 1,430,788 2,029,843 1,430,788 2,029,843 Unvested restricted stock units 160,900 80,450 160,900 80,450 Total 1,591,688 2,110,293 1,591,688 2,110,293

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
Summary of Investments by Category	The following table summarizes the Company’s investments, by category, as of June 30, 2020 (in thousands): Investments - Current: June 30, 2020 Debt securities - available-for-sale $ 40,469 Total $ 40,469
Summary of Available-for-Sale Classified Investments	A summary of the Company’s available-for-sale classified investments as of June 30, 2020 consisted of the following (in thousands): At June 30, 2020 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value United States Treasury securities $ 35,973 $ - $ - $ 35,973 Mortgage-backed securities 4,496 - - 4,496 Total $ 40,469 $ - $ - $ 40,469
Summary of Amortized Cost and Fair Value of Available-for-Sale Investments by Contract Maturity	The amortized cost and fair value of the Company’s available-for-sale investments, by contract maturity, as of June 30, 2020 consisted of the following (in thousands): Amortized Cost Fair Value Due in one year or less $ 40,469 $ 40,469 Total $ 40,469 $ 40,469

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2019 June 30, 2020 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 (102 ) (119 ) Property and equipment, net $ 127 $ 110

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2020
Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following (in thousands): December 31, 2019 June 30, 2020 Contract research and development $ 2,001 $ 2,937 Employee compensation and related costs 1,250 1,315 Consulting and professional service fees 296 364 Interest 91 85 State taxes 49 20 Other 1 3 Total accrued expenses $ 3,688 $ 4,724

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
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: Six Months Ended June 30, 2019 2020 Risk-free interest rate 1.85%-2.51% 0.41% - 1.71% Expected dividend yield 0% 0% Expected life 5.5-6.0 years 5.5-6.6 years Expected volatility 73%-74% 72%-75% Weighted-average grant date fair value $ 2.14 $ 4.06
Summary of Information about Stock Option Activity	The following table summarizes information about stock option activity during the six months ended June 30, 2020 (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, 2019 1,439,518 $ 6.09 Granted 763,702 6.32 Exercised (115,671 ) 6.18 Forfeited (57,706 ) 9.97 Outstanding, June 30, 2020 2,029,843 $ 6.06 8.08 $ 4,128 Vested and exercisable, June 30, 2020 956,575 $ 5.69 7.00 $ 2,435 Vested and expected to vest, June 30, 2020 1,669,947 $ 6.01 7.80 $ 3,605
Schedule of RSU Activity	The following table summarizes information about RSU activity during the six months ended June 30, 2020: RSUs AVERAGE GRANT DATE FAIR VALUE (IN DOLLARS PER SHARE) Outstanding, December 31, 2019 160,900 $ 3.25 Granted — — Vested (80,450 ) 3.25 Forfeited — — RSUs outstanding at June 30, 2020 80,450 $ 3.25
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 six months ended June 30, 2019 and 2020 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2020 2019 2020 Research and development $ 72 $ 177 $ 140 $ 321 General and administrative 254 444 541 808 Total $ 326 $ 621 $ 681 $ 1,129

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Summary of Assets Measured at Fair Value on Recurring Basis	The following table summarizes the Company’s assets as of June 30, 2020 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 $ 78,165 $ 78,165 $ — $ — Total cash equivalents 78,165 78,165 — — United States Treasury securities 35,973 35,973 — — Mortgage-backed securities 4,496 — 4,496 — Investments 40,469 35,973 4,496 — Total $ 118,634 $ 114,138 $ 4,496 $ —

Term Loan (Tables)

Term Loan (Tables)	6 Months Ended
	Jun. 30, 2020
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): June 30, 2020 Face value $ 20,000 Less: discount (924 ) Total $ 19,076 Less: current portion - Total $ 19,076
Schedule of Future Principal Payments Due	As of June 30, 2020, 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)	6 Months Ended
	Jun. 30, 2020
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 June 30, 2020 (in thousands): Year ended: December 31, 2020 $ 266 December 31, 2021 537 December 31, 2022 496 Total minimum lease payments 1,299 Less imputed interest (147 ) Total $ 1,152
Schedule of Lease Cost and Other Information of Operating Lease Liabilities	Six Months Ended June 30, 2019 2020 Lease cost: Operating lease cost $ 246 $ 243 Short-term lease cost 4 - Sublease income (25 ) (25 ) Total lease cost $ 225 $ 218 Other information Cash paid for amounts included in the measurement of lease liabilities $ 254 $ 267 Operating cash flows from operating leases $ (13 ) $ (20 ) Weighted-average remaining lease term - operating leases 3.4 years 2.4 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 ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ (144,842)	$ (129,455)
Cash, cash equivalents, restricted cash, and marketable securities	$ 119,500

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Schedule Of Accounting Policies [Line Items]
Restricted cash	$ 182,000	$ 182,000
Potential interest and penalties associated with uncertain tax positions, accruals	0
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	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 78,860	$ 72,624
Restricted cash	182	182
Cash, cash equivalents and restricted cash	$ 79,042	$ 72,806	$ 79,649	$ 89,660

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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net loss and comprehensive loss	$ (8,295)	$ (7,255)	$ (15,387)	$ (15,974)
Weighted-average shares used in computing net loss per share	23,355,418	18,580,430	21,786,946	18,578,091
Net loss per share, basic and diluted	$ (0.36)	$ (0.39)	$ (0.71)	$ (0.86)

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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	2,110,293	1,591,688	2,110,293	1,591,688
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	2,029,843	1,430,788	2,029,843	1,430,788
Unvested Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	80,450	160,900	80,450	160,900

Investments - Summary of Invest

Investments - Summary of Investments by Category (Details) $ in Thousands	Jun. 30, 2020USD ($)
Investments Debt And Equity Securities [Abstract]
Debt securities - available-for-sale	$ 40,469
Total	$ 40,469

Investments - Summary of Availa

Investments - Summary of Available-for-Sale Classified Investments (Details) $ in Thousands	Jun. 30, 2020USD ($)
Marketable Securities [Line Items]
Cost Basis	$ 40,469
Fair Value	40,469
United States Treasury Securities
Marketable Securities [Line Items]
Cost Basis	35,973
Fair Value	35,973
Mortgage-Backed Securities
Marketable Securities [Line Items]
Cost Basis	4,496
Fair Value	$ 4,496

Investments - Summary of Amorti

Investments - Summary of Amortized Cost and Fair Value of Available-for-Sale Investments by Contract Maturity (Details) $ in Thousands	Jun. 30, 2020USD ($)
Investments Debt And Equity Securities [Abstract]
Amortized Cost, Due in one year or less	$ 40,469
Amortized Cost, Total	40,469
Fair Value, Due in one year or less	40,469
Fair Value, Total	$ 40,469

Property and Equipment - Schedu

Property and Equipment - Schedule of Purchased Property and Equipment (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 229	$ 229
Less: Accumulated depreciation	(119)	(102)
Property and equipment, net	$ 110	127
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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Property Plant And Equipment [Abstract]
Depreciation expense	$ 9,000	$ 9,000	$ 17,000	$ 19,000

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accruals [Abstract]
Contract research and development	$ 2,937	$ 2,001
Employee compensation and related costs	1,315	1,250
Consulting and professional service fees	364	296
Interest	85	91
State taxes	20	49
Other	3	1
Total accrued expenses	$ 4,724	$ 3,688

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	Jul. 02, 2020	Jun. 30, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional options granted		763,702
Stock option, number of shares outstanding		2,029,843	1,439,518
Unrecognized compensation expense		$ 2,600,000
Recognition period (in years)		2 years
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense		$ 177,000
Recognition period (in years)		7 months 6 days
Number of restricted stock units vested		80,450
Restricted Stock Units (RSUs) | Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common shares issued related to vesting	31,962
Restricted Stock Units (RSUs) | Regulatory Milestone
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of restricted stock units vested		42,250
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional options granted		226,110
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		1,326,207
Number of common shares authorized for issuance		3,894,270
Stock options, available for issuance		2,466,174
Term of option 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		80,450
2017 Stock Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting term		1 year
2017 Stock Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option 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		703,636
Number of options forfeited		265,203

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Estimated Fair Value of Options Valuation Assumptions (Details) - $ / shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	0.41%	1.85%
Risk-free interest rate, maximum	1.71%	2.51%
Expected dividend yield	0.00%	0.00%
Expected volatility, minimum	72.00%	73.00%
Expected volatility, maximum	75.00%	74.00%
Weighted-average grant date fair value	$ 4.06	$ 2.14
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 7 months 6 days	6 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Information about Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2020
NUMBER OF SHARES
Number of shares outstanding, beginning balance	1,439,518
Number of shares granted	763,702
Number of shares exercised	(115,671)
Number of shares forfeited	(57,706)
Number of shares outstanding, ending balance	2,029,843
Vested and exercisable, ending balance	956,575
Vested and expected to vest, ending balance	1,669,947
WEIGHTED-AVERAGE EXERCISE PRICE
Weighted average exercise prices, outstanding beginning balance	$ 6.09
Weighted average exercise prices, granted	6.32
Weighted average exercise prices, exercised	6.18
Weighted average exercise prices, forfeited	9.97
Weighted average exercise prices, outstanding ending balance	6.06
Weighted average exercise prices, vested and exercisable ending balance	5.69
Weighted average exercise prices, vested and expected to vest ending balance	$ 6.01
WEIGHTED-AVERAGE REMAINING CONTRACTUAL TERM
Weighted average remaining contractual term, outstanding	8 years 29 days
Weighted average remaining contractual term, vested and exercisable	7 years
Weighted average remaining contractual term, vested and expected to vest	7 years 9 months 18 days
AGGREGATE INTRINSIC VALUE
Aggregate intrinsic value, outstanding ending balance	$ 4,128
Aggregate intrinsic value, vested and exercisable ending balance	2,435
Aggregate intrinsic value, vested and expected to vest ending balance	$ 3,605

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of RSU Activity (Details) - Restricted Stock Units (RSUs)	6 Months Ended
	Jun. 30, 2020$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs Outstanding, December 31, 2019 | shares	160,900
RSUs Vested | shares	(80,450)
RSUs outstanding at June 30, 2020 | shares	80,450
AVERAGE GRANT DATE FAIR VALUE, Outstanding, December 31, 2019 | $ / shares	$ 3.25
AVERAGE GRANT DATE FAIR VALUE, Vested | $ / shares	3.25
AVERAGE GRANT DATE FAIR VALUE, RSUs outstanding at June 30, 2020 | $ / shares	$ 3.25

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 621	$ 326	$ 1,129	$ 681
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	177	72	321	140
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 444	$ 254	$ 808	$ 541

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Summary of Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring $ in Thousands	Jun. 30, 2020USD ($)
Assets
Cash equivalents	$ 78,165
Investments	40,469
Total	118,634
United States Treasury Securities
Assets
Investments	35,973
Mortgage-Backed Securities
Assets
Investments	4,496
Quoted Prices in Active Markets (Level 1) [Member]
Assets
Cash equivalents	78,165
Investments	35,973
Total	114,138
Quoted Prices in Active Markets (Level 1) [Member] | United States Treasury Securities
Assets
Investments	35,973
Significant Other Observable Inputs (Level 2) [Member]
Assets
Investments	4,496
Total	4,496
Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Securities
Assets
Investments	$ 4,496

Term Loan - Additional Informat

Term Loan - Additional Information (Details) - USD ($)	1 Months Ended			3 Months Ended		6 Months Ended
	Sep. 30, 2019	Nov. 30, 2018	May 31, 2017	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Debt Instrument [Line Items]
Fair value adjustment to derivative liability						$ 30,000
Solar Capital Ltd. and Silicon Valley Bank | 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					$ 66,000		$ 116,000
Prepayment premium thereafter						1.00%
Final payment fee						$ 250,000
Amortization of final payment fee					$ 27,000		$ 57,000
Payment of final fee	$ 325,000
Solar Capital Ltd. and Silicon Valley Bank | 2017 Loan Agreement | Libor
Debt Instrument [Line Items]
Basis spread on variable base rate			8.45%
Solar Capital Ltd. and Silicon Valley Bank | First Amendment to Loan and Security Agreement
Debt Instrument [Line Items]
Final payment fee		$ 325,000
Solar Capital Ltd. and Silicon Valley Bank | 2019 Loan Agreement
Debt Instrument [Line Items]
Loan and security agreement, amount	$ 20,000,000
Loan agreement, maturity date	Sep. 17, 2023
Amortization of debt discount				$ 85,000		166,000
Final payment fee						500,000
Amortization of final payment fee				$ 40,000		$ 80,000
Loan agreement, term	4 years
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%
Exit fee, percentage						4.00%
Exit fee						$ 800,000
Derivative liability recorded against exit fee obligation				$ 763,000		763,000
Fair value adjustment to derivative liability						30,000
Unpaid borrowings				$ 20,000,000		$ 20,000,000
Prepayment premium percentage after year two						0.50%
Increase in interest rate on default						5.00%
Solar Capital Ltd. and Silicon Valley Bank | 2019 Loan Agreement | Minimum
Debt Instrument [Line Items]
Interest rate, minimum				10.18%		10.18%
Prepayment premium percentage						1.00%
Solar Capital Ltd. and Silicon Valley Bank | 2019 Loan Agreement | Maximum
Debt Instrument [Line Items]
Prepayment premium percentage						3.00%
Solar Capital Ltd. and Silicon Valley Bank | 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	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total	$ 19,076	$ 18,915
2019 Loan Agreement | Solar Capital Ltd. and Silicon Valley Bank
Debt Instrument [Line Items]
Face value	20,000
Less: discount	(924)
Total	19,076
Total	$ 19,076

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	Jun. 30, 2020USD ($)
Debt Instrument [Line Items]
December 31, 2021	$ 2,500
December 31, 2022	10,000
December 31, 2023	7,500
Total	$ 20,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)	Aug. 23, 2019	Jun. 30, 2020	May 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020
ATM Agreement | Additional Paid-in Capital | Legal Accounting and Other Costs
Stockholders Equity Note [Line Items]
Stock issuance cost						$ 135,000
ATM Agreement | Jefferies | Common Stock
Stockholders Equity Note [Line Items]
Percentage of commission on gross sales proceeds	3.00%
Number of shares sold					1,502,892
Proceeds from sale of shares,Net					$ 10,400,000
ATM Agreement | Jefferies | Common Stock | Maximum
Stockholders Equity Note [Line Items]
Aggregate offering price	$ 15,000,000
ATM Agreement | Jefferies | Common Stock | Weighted Average
Stockholders Equity Note [Line Items]
Selling price per share					$ 7.13
Underwritten Public Offering | Common Stock
Stockholders Equity Note [Line Items]
Number of shares sold		440,242	5,780,347	6,220,589
Selling price per share		$ 8.65	$ 8.65	$ 8.65		$ 8.65
Proceeds from sale of shares,Net		$ 3,600,000	$ 46,600,000
Underwritten Public Offering | Common Stock | Maximum
Stockholders Equity Note [Line Items]
Option granted to purchase additional shares			867,052

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	1 Months Ended	6 Months Ended
	Feb. 28, 2018	Jun. 30, 2020	Dec. 31, 2019
Commitments And Contingencies [Line Items]
Operating leases expire		2022
Restricted cash		$ 182,000	$ 182,000
Short-term lease asset		1,002,000	1,179,000
Short-term lease liability		435,000	$ 407,000
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	Jun. 30, 2020USD ($)
Year ended:
December 31, 2020	$ 266
December 31, 2021	537
December 31, 2022	496
Total minimum lease payments	1,299
Less imputed interest	(147)
Total	$ 1,152

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Lease Cost and Other Information of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Lease cost:
Operating lease cost	$ 243	$ 246
Short-term lease cost		4
Sublease income	(25)	(25)
Total lease cost	218	225
Other information
Cash paid for amounts included in the measurement of lease liabilities	267	254
Operating cash flows from operating leases	$ (20)	$ (13)
Weighted-average remaining lease term - operating leases	2 years 4 months 24 days	3 years 4 months 24 days
Weighted-average discount rate - operating leases	10.10%	10.10%