Trevena (TRVN) 10-K 9 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Mar. 05, 2021	Jun. 30, 2020
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	001-36193
Entity Registrant Name	TREVENA INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-1469215
Entity Address, Address Line One	955 Chesterbrook Blvd.
Entity Address, Address Line Two	Suite 110
Entity Address, City or Town	Chesterbrook
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19087
City Area Code	610
Local Phone Number	354-8840
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	TRVN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float			$ 189.4
Entity Common Stock, Shares Outstanding		161,273,660
Entity Central Index Key	0001429560
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 109,403	$ 32,305
Accounts receivable, net	71
Marketable securities		3,500
Insurance recovery	9,000
Prepaid expenses and other current assets	570	1,683
Total current assets	119,044	37,488
Restricted cash	1,310	1,309
Property and equipment, net	2,253	2,705
Right-of-use lease asset	5,119	5,472
Other assets	13	20
Total assets	127,739	46,994
Current liabilities:
Accounts payable, net	1,693	1,047
Accrued expenses and other current liabilities	5,168	2,403
Estimated settlement liability	9,000
Current portion of loans payable, net		5,037
Lease liability	703	620
Total current liabilities	16,564	9,107
Leases, net of current portion	7,101	7,804
Warrant liability	6	5
Total liabilities	23,671	16,916
Commitments and contingencies (Note 8)
Stockholders' equity:
Common stock-$0.001 par value; 200,000,000 shares authorized at December 31, 2020 and December 31, 2019; 159,999,917 and 94,213,760 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively	160	94
Preferred stock-$0.001 par value; 5,000,000 shares authorized, none issued or outstanding at December 31, 2020 and December 31, 2019
Additional paid-in capital	546,422	443,129
Accumulated deficit	(442,514)	(413,145)
Total stockholders' equity	104,068	30,078
Total liabilities and stockholders' equity	$ 127,739	$ 46,994

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Balance Sheets
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock authorized (in shares)	200,000,000	200,000,000
Common stock issued (in shares)	159,999,917	94,213,760
Common stock outstanding (in shares)	159,999,917	94,213,760
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock authorized (in shares)	5,000,000	5,000,000
Preferred stock issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue:
Total revenue	$ 3,069	$ 31
Operating expenses:
Cost of goods sold	182
General and administrative	19,248	13,212
Research and development	13,124	13,291
Impairment of property and equipment	0	108
Total operating expenses	32,554	26,611
Loss from operations	(29,485)	(26,580)
Other income (expense):
Change in fair value of warrant liability	(1)	(4)
Other income, net	205	2,222
Interest income	240	418
Interest expense	(29)	(931)
Total other income	416	1,709
Loss before income tax expense	(29,069)	(24,871)
Foreign income tax expense	(300)
Net loss attributable to common stockholders	(29,369)	(24,871)
Other comprehensive (loss) gain, net:
Unrealized gain on marketable securities		9
Other comprehensive gain, net		9
Comprehensive loss	$ (29,369)	$ (24,862)
Per share information:
Net loss per share of common stock, basic and diluted (in dollars per share)	$ (0.23)	$ (0.27)
Weighted average common shares outstanding, basic and diluted (in shares)	127,623,859	91,677,963
Product revenue
Revenue:
Total revenue	$ 69
License revenue
Revenue:
Total revenue	$ 3,000	$ 31

Statements of Stockholders' Equ

Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Total
Beginning Balance at Dec. 31, 2018	$ 82	$ 429,727	$ (388,274)	$ (9)	$ 41,526
Balance (in shares) at Dec. 31, 2018	82,323,413
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense		3,232			3,232
Exercise of stock options		28			28
Exercise of stock options (in shares)	41,968
Issuance of warrants to underwriters in connection with equity offering		347			347
Issuance of common stock, net of issuance costs	$ 12	9,953			9,965
Issuance of common stock, net of issuance costs (in shares)	11,442,408
Shares repurchased by the Company (in shares)	(122)
Issuance of common stock upon vesting of RSUs, net of shares withheld for employee taxes		(158)			(158)
Issuance of common stock upon vesting of RSUs, net of shares withheld for employee taxes (in shares)	406,093
Unrealized gain on marketable securities				$ 9	9
Net loss			(24,871)		(24,871)
Ending Balance at Dec. 31, 2019	$ 94	443,129	(413,145)		$ 30,078
Balance (in shares) at Dec. 31, 2019	94,213,760				94,213,760
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense		3,284			$ 3,284
Exercise of stock options	$ 1	135			136
Exercise of stock options (in shares)	197,640
Net exercise of common stock warrant (in shares)	201,925
Issuance of common stock, net of issuance costs	$ 64	100,946			101,010
Issuance of common stock, net of issuance costs (in shares)	64,344,354
Issuance of common stock upon vesting of RSUs, net of shares withheld for employee taxes	$ 1	(1,072)			(1,071)
Issuance of common stock upon vesting of RSUs, net of shares withheld for employee taxes (in shares)	1,042,238
Net loss			(29,369)		(29,369)
Ending Balance at Dec. 31, 2020	$ 160	$ 546,422	$ (442,514)		$ 104,068
Balance (in shares) at Dec. 31, 2020	159,999,917				159,999,917

Statement of Stockholders' Equi

Statement of Stockholders' Equity (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common Stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (29,369)	$ (24,871)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	477	562
Stock-based compensation	3,284	3,232
Noncash interest expense on loans	8	331
Impairment of property and equipment	0	108
Loss on disposal of assets	2	12
Revaluation of warrant liability	1	4
Accretion of bond discount on marketable securities		(484)
Change in right-of-use asset	353	301
Changes in operating assets and liabilities:
Accounts receivable, prepaid expenses and other assets	1,049	(1,122)
Operating lease liabilities	(610)	(482)
Accounts payable, accrued expenses and other liabilities	3,411	(1,258)
Net cash used in operating activities	(21,394)	(23,667)
Investing activities:
Purchases of property and equipment	(27)
Maturities of marketable securities	3,500	79,389
Purchases of marketable securities		(53,806)
Net cash provided by investing activities	3,473	25,583
Financing activities:
Proceeds from exercise of common stock options	136	28
Proceeds from issuance of common stock, net	101,010	10,312
Payment of employee withholding taxes on vested restricted stock units	(1,071)	(158)
Capital lease payments	(10)	(12)
Repayments of loans payable, net	(5,045)	(12,667)
Net cash provided by (used in) financing activities	95,020	(2,497)
Net increase (decrease) in cash, cash equivalents and restricted cash	77,099	(581)
Cash, cash equivalents and restricted cash-beginning of period	33,614	34,195
Cash, cash equivalents and restricted cash-end of period	110,713	33,614
Supplemental disclosure of cash flow information:
Cash paid for interest	$ 19	600
Fair value of common stock warrants issued to underwriters		$ 347

Organization and Description of

Organization and Description of the Business	12 Months Ended
	Dec. 31, 2020
Organization and Description of the Business
Organization and Description of the Business	1. Organization and Description of the Business Trevena, Inc., or the Company, was incorporated in Delaware as Parallax Therapeutics, Inc. on November 9, 2007. The Company began operations in December 2007, and its name was changed to Trevena, Inc. on January 3, 2008. The Company is a biopharmaceutical company focused on the development and commercialization of novel medicines for patients affected by central nervous system, or CNS, disorders. The Company operates in one segment and has its principal office in Chesterbrook, Pennsylvania. Since commencing operations in 2007, the Company has devoted substantially all of its financial resources and efforts to research and development, including nonclinical studies and clinical trials. The Company has never been profitable. In late 2017, the Company submitted a new drug application, or NDA, for OLINVYK™ (OLINVYK) injection, or OLINVYK, to the United States Food and Drug Administration, or the FDA. In August 2020, the FDA approved the NDA for OLINVYK and the Company initiated commercial launch of OLINVYK in the first quarter of 2021. Since the Company’s inception, the Company has incurred losses and negative cash flows from operations. At December 31, 2020, the Company had an accumulated deficit of $442.5 million. The Company’s net loss was $29.4 million and $24.9 million for the years ended December 31, 2020 and 2019, respectively. The Company follows the provisions of Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 205-40, Presentation of Financial Statements—Going Concern Certain prior period amounts have been reclassified to conform to the current period presentation, the effect of which was not material to the Company’s interim financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or U.S. GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the ASC and Accounting Standards Updates, or ASUs, of the FASB. The Company’s functional currency is the U.S. dollar. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Management used significant estimates in the following areas, among others: stock-based compensation expense, the determination of the fair value of stock-based awards, the fair value of common stock warrants, the accounting for research and development costs, accrued expenses and the recoverability of the Company’s net deferred tax assets and related valuation allowance. The Company is also subject to certain contingent liabilities with respect to existing or potential claims, lawsuits and other proceedings. The Company accrues liabilities when it considers probable that future costs will be incurred and such costs can be reasonably estimated, and recognizes an asset for proceeds from related insurance claims that are considered probable of recovery. The financial data and other information disclosed in these notes are not necessarily indicative of the results to be expected for any future year or period. The Company bases its estimates on historical experience and also on assumptions that it believes are reasonable, however, actual results could significantly differ from those results. Cash, Cash Equivalents and Marketable Securities The Company considers all highly liquid investments that have maturities of three months or less when acquired to be cash equivalents. Cash equivalents are valued at cost, which approximates their fair market value. The Company maintains a portion of its cash and cash equivalent balances in money market mutual funds that may invest substantially all of their assets in U.S. government agency securities and U.S. Treasury securities. The Company classifies its marketable securities as “available-for-sale,” pursuant to ASC Topic 320, Investments—Debt and Equity Securities The fair value of the Company’s investments is determined based on observable market quotes or valuation models using assessments of counterparty credit worthiness, credit default risk of underlying security and overall capital market liquidity. The Company reviews unrealized losses associated with available-for-sale securities to determine the classification as “temporary” or “other-than-temporary” impairment. A temporary impairment results in an unrealized loss being recorded in other comprehensive income (loss). If a decline in the fair value is considered other-than-temporary, based on available evidence, the unrealized loss is transferred from other comprehensive income (loss) to the statement of operations. The Company considers various factors in determining the classification, including the length of time and extent to which the fair value has been less than the Company’s cost basis, the financial condition and near-term prospects of the issuer or investee, and the Company’s ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. Realized gains (losses) are included in interest income (expense) in the statement of operations and comprehensive income (loss) on a specific identification basis. Restricted Cash The Company maintains $1.3 million as collateral under a letter of credit for the Company’s facility lease obligations in Chesterbrook, Pennsylvania. The Company has recorded this deposit and accumulated interest thereon as restricted cash on its balance sheet. Fair Value of Financial Instruments The carrying amount of the Company’s financial instruments, which include cash and cash equivalents, marketable securities, restricted cash, accounts payable and accrued expenses approximate their fair values, given their short-term nature. The carrying amount of the Company’s loans payable at December 31, 2019 is the nominal value of the loan payable, net of unamortized debt discount and deferred charges. The Company had no loans payable at December 31, 2020. The nominal value approximates fair value because the interest rate is reflective of the rate the Company could obtain on debt with similar terms and conditions. Certain of the Company’s common stock warrants are carried at fair value, as disclosed in Note 3. The Company has evaluated the estimated fair value of financial instruments using available market information and management’s estimates. The use of different market assumptions and/or estimation methodologies could have a significant effect on the estimated fair value amounts. See Note 3 for additional information. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents, marketable securities and restricted cash. The Company’s investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. The Company has no off-balance sheet concentrations of credit risk such as foreign currency exchange contracts, option contracts or other hedging arrangements. Property and Equipment Property and equipment consists of computer and laboratory equipment, software, office equipment, furniture, manufacturing equipment and leasehold improvements and is recorded at cost. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Upon disposal, retirement or sale, the related cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the results of operations. Property and equipment are depreciated on a straight-line basis over their estimated useful lives. The Company uses a life of three years for computer equipment and five years for laboratory equipment, office equipment, furniture, manufacturing equipment and software. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the asset. The Company reviews long-lived assets when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets. $0.1 million of impairment losses were recorded during the year ended December 31, 2019. No impairment losses were recorded during the year ended December 31, 2020. Leases At the commencement of a lease, the Company recognizes a liability to make lease payments and an asset representing the right to use the underlying asset during the lease term. The lease liability is measured at the present value of lease payments over the lease term, including variable fees that are known or subject to a minimum floor. The lease liability includes lease component fees, while non-lease component fees are expensed as incurred for all asset classes. When a contract excludes an implicit rate, the Company utilizes an incremental borrowing rate based on information available at the lease commencement date including lease term and geographic region. The initial valuation of the right-of-use, or ROU, asset includes the initial measurement of the lease liability, lease payments made in advance of the lease commencement date, and initial direct costs incurred by the Company and excludes lease incentives. Leases with an initial term of 12 months or less are classified as short-term leases and are not recorded on the balance sheet. The lease expense for short-term leases is recognized on a straight-line basis over the lease term. The Company tests for impairment of the ROU assets whenever circumstances indicate that the carrying amount of the asset may not be recoverable. Common Stock Warrants Freestanding warrants that are related to the purchase of common stock are classified as liabilities and recorded at fair value regardless of the timing of the redemption feature or the redemption price or the likelihood of redemption. These warrants are subject to re-measurement at each balance sheet date and any change in fair value is recognized as a component of change in fair value of warrant liability in the statements of operations and comprehensive loss. The Company will continue to adjust the liability for changes in fair value until the earlier of the exercise or expiration of the warrants. The warrants are classified as Level 3 liabilities. The value of these warrants was immaterial as of December 31, 2020 and 2019. In addition, in connection with entering into loan agreements, the Company has issued warrants to purchase shares of the Company’s common stock. These detachable warrant instruments qualify for equity classification and have been allocated upon the relative fair value of the base instrument and the warrant. See Note 6 and Note 7 for additional information. Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company’s chief operating decision maker is the chief executive officer. The Company and the chief executive officer view the Company’s operations and manage its business as one operating segment. All long-lived assets of the Company reside in the United States. Revenue In accordance with FASB’s ASC 606, Revenue from Contracts with Customers, or ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, it performs the following five steps: (i) (ii) (iii) (iv) (v) The Company applies the five-step model to contracts when it determines that it is probable it will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. See Note 9 and Note 10, respectively, for a full discussion of the Company’s product revenue and license revenue. Research and Development Research and development costs are charged to expense as incurred. Research and development costs include, but are not limited to, personnel expenses, clinical trial supplies, fees for clinical trial services, manufacturing costs, consulting costs, and allocated overhead, including rent, equipment depreciation, and utilities. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as subject enrollment, clinical site activations or information provided to the Company by its vendors with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid or accrued research and development expense, as the case may be. As part of the process of preparing its financial statements, the Company is required to estimate its expenses resulting from its obligations under contracts with vendors, clinical research organizations and consultants, and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company’s objective is to reflect the appropriate trial expenses in its financial statements by matching those expenses with the period in which services are performed and efforts are expended. The Company may account for these expenses according to the progress of the trial as measured by subject progression and the timing of various aspects of the trial. The Company determines accrual estimates through financial models taking into account discussion with applicable personnel and outside service providers as to the progress or state of consummation of trials, or the services completed. During the course of a clinical trial, the Company adjusts its clinical expense recognition if actual results differ from its estimates. The Company makes estimates of its accrued expenses as of each balance sheet date based on the facts and circumstances known to it at that time. The Company’s clinical trial accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in it reporting amounts that are too high or too low for any particular period. For the years ended December 31, 2020 and 2019, there were no material adjustments to the Company’s prior period estimates of accrued expenses for clinical trials. Stock-Based Compensation The Company has equity incentive plans under which various types of equity-based awards including, but not limited to, incentive stock options, non-qualified stock options, and restricted stock unit awards, may be granted to employees, non-employee directors, and non-employee consultants. At December 31, 2020, the Company had two stock-based compensation plans, which are more fully described in Note 7. The Company also has an inducement plan under which various types of equity-based awards, including non-qualified stock options and restricted stock awards, may be granted to new employees. The Company has applied the fair value recognition provisions of Financial Accounting Standards Board Accounting Standards Codification Topic 718, Compensation — Stock Compensation, to account for stock-based compensation for employees. The Company recognizes compensation expense for all stock-based awards based on the estimated grant-date fair values. For restricted stock unit awards to employees, the fair value is based on the closing price of the Company’s common stock on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as expense on a straight-line basis over the requisite service period. The fair value of stock options is determined using the Black-Scholes option pricing model. The Company utilizes a dividend yield of zero based on the fact that the Company has never paid cash dividends and has no current intention of paying cash dividends. The Company elected an accounting policy to record forfeitures as they occur. For stock awards that vest based on performance conditions (e.g., achievement of certain milestones), expense is recognized when it is probable that the conditions will be met. See Note 7 for a discussion of the assumptions used by the Company in determining the grant date fair value of options granted under the Black-Scholes option pricing model, as well as a summary of the stock option activity under the Company’s stock-based compensation plan for all years presented. Income Taxes Income taxes are recorded in accordance with ASC Topic 740, Income Taxes The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position, as well as consideration of the available facts and circumstances. To date, the Company has not taken any uncertain tax position or recorded any reserves, interest or penalties. On December 22, 2017, the U.S. government enacted comprehensive tax legislation informally titled the Tax Cuts and Jobs Act of 2017, or the Tax Act. Additionally, the SEC staff issued SAB 118, which provides guidance on accounting for the effects of the Tax Act. See Note 14. Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Comprehensive income (loss) relates to unrealized investment gains or losses on the Company’s marketable securities for all periods presented. Basic and Diluted Net Loss Per Share of Common Stock The Company’s basic net loss per share is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. The diluted net loss per common share is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. Because the impact of these items is anti-dilutive during periods of net loss, there was no difference between basic and diluted net loss per share of common stock for all periods presented. Recently Adopted Accounting Standards In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement Fair Value Measurement Recent Accounting Standards Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes ​

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2020
Fair Value of Financial Instruments
Fair Value of Financial Instruments	3. Fair Value of Financial Instruments ASC Topic 820, Fair Value Measurement, ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes among the following: Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. Level 2—Valuations based on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active and models for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations based on inputs that are unobservable and significant to the overall fair value measurement. To the extent that the 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. Cash, Cash Equivalents, Restricted Cash, and Marketable Securities The following table presents the Company’s cash, cash equivalents, restricted cash, and marketable securities as of December 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Adjusted ​ Unrealized ​ Unrealized ​ ​ ​ ​ Cash and Cash ​ Restricted ​ Marketable ​ ​ Cost Gains Losses Fair Value Equivalents Cash Securities Cash ​ $ 6,100 ​ $ — ​ $ — ​ $ 6,100 ​ $ 4,790 ​ $ 1,310 ​ $ — Level 1 (1): ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ 104,613 ​ — ​ — ​ 104,613 ​ 104,613 ​ — ​ — U.S. treasury securities ​ — ​ — ​ — ​ — ​ — ​ — ​ — Subtotal ​ 104,613 ​ — ​ — ​ 104,613 ​ 104,613 ​ — ​ — Level 2 (2): ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ — ​ — ​ — ​ — ​ — ​ — ​ — Total ​ $ 110,713 ​ $ — ​ $ — ​ $ 110,713 ​ $ 109,403 ​ $ 1,310 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ Adjusted ​ Unrealized ​ Unrealized ​ ​ ​ ​ Cash and Cash ​ Restricted ​ Marketable ​ Cost Gains Losses Fair Value Equivalents Cash Securities Cash ​ $ 9,302 ​ $ — ​ $ — ​ $ 9,302 ​ $ 7,993 ​ $ 1,309 ​ $ — Level 1 (1): ​ ​ ​ ​ ​ ​ ​ Money market funds ​ 18,306 ​ — ​ — ​ 18,306 ​ 18,306 ​ — ​ — U.S. treasury securities ​ ​ 5,996 ​ — ​ — ​ 5,996 ​ 2,496 ​ — ​ 3,500 Subtotal ​ 24,302 ​ — ​ — ​ 24,302 ​ 20,802 ​ — ​ 3,500 Level 2 (2): ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ 3,510 ​ — ​ — ​ 3,510 ​ 3,510 ​ — ​ — Total ​ $ 37,114 ​ $ — ​ $ — ​ $ 37,114 ​ $ 32,305 ​ $ 1,309 ​ $ 3,500 (1) The fair value of Level 1 securities is estimated based on quoted prices in active markets for identical assets or liabilities. (2) The fair value of Level 2 securities is estimated based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term on the assets or liabilities. The Company classifies investments available to fund current operations as current assets on its balance sheets. As of December 31, 2020, the Company did not hold any investment securities exceeding a one-year maturity. The Company maintains $1.3 million as collateral under a letter of credit for the Company’s facility lease obligations in Chesterbrook, Pennsylvania. The Company has recorded this deposit and accumulated interest thereon as restricted cash on its balance sheet. Unrealized gains and losses on marketable securities are recorded as a separate component of accumulated other comprehensive income (loss) included in stockholders’ equity. Realized gains (losses) are included in interest income (expense) in the statement of operations and comprehensive income (loss) on a specific identification basis. The Company did not record any realized gains or losses on marketable securities during the years ended December 31, 2020 and 2019. To date, the Company has not recorded any impairment charges on marketable securities related to other-than-temporary declines in market value. Accretion of bond discount on marketable securities is included in other income as a separate component of other income (expense) on the statement of operations and comprehensive loss. Interest income on marketable securities is recorded as interest income on the statement of operations and comprehensive loss. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. The Company does not hold material Level 3 securities, and therefore, there were no transfers in or out of Level 3 in the hierarchy during the years ended December 31, 2020 or 2019.

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2020
Property and Equipment, net
Property and Equipment, net	4. Property and Equipment, net Property and equipment consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated ​ ​ ​ ​ ​ ​ ​ ​ Useful ​ December 31, ​ Life in Years 2020 2019 Computers and software ​ 3 5 ​ $ 476 ​ $ 480 Office equipment and furniture ​ 5 ​ 721 ​ 706 Manufacturing equipment ​ 5 ​ 10 ​ 10 Leasehold improvements ​ 10 ​ 3,082 ​ 3,082 Leased assets ​ 5 ​ 45 ​ 45 Total property and equipment ​ ​ ​ 4,334 ​ 4,323 Less accumulated depreciation and amortization ​ ​ ​ (2,081) ​ (1,618) Property and equipment, net ​ ​ ​ ​ $ 2,253 ​ $ 2,705 ​ Depreciation and amortization expense was $0.5 million and $0.6 million for the years ended December 31, 2020 and 2019, respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2020
Accrued Expenses and Other Current Liabilities
Accrued Expenses and Other Current Liabilities	5. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Compensation and benefits ​ $ 2,919 ​ $ 1,786 Commercial expenses ​ ​ 605 ​ ​ — Legal expenses ​ ​ 784 ​ ​ 86 Pharmaceutical development expenses ​ 413 ​ 445 Accrued interest ​ — ​ 18 Other accrued expenses and other current liabilities ​ 447 ​ 68 Total accrued expenses and other current liabilities ​ $ 5,168 ​ $ 2,403 ​

Loans Payable

Loans Payable	12 Months Ended
	Dec. 31, 2020
Loans Payable
Loans Payable	6. Loans Payable In September 2014, the Company entered into a loan and security agreement with Oxford Finance LLC and Pacific Western Bank (formerly Square 1 Bank) (together, the lenders), pursuant to which the lenders agreed to lend the Company up to $35.0 million in a three-tranche series of term loans (Term Loans A, B, and C). In September 2014, December 2015 and March 2017, the Company incurred borrowings under the agreement in the aggregate initial principal amount of $28.5 million. Term Loans A and B accrued interest at 6.5% per annum and Term Loan C accrued interest at 6.98% per annum. The Company was required to make payments of interest only on borrowings under the loan agreement on a monthly basis through and including January 1, 2018; payments of principal in equal monthly installments and accrued interest began on January 1, 2018 and continued until the loan matured on March 1, 2020. On March 2, 2020, the Company made its final payment under the loan and security agreement with the lenders. Upon the last payment date of the amounts borrowed under the agreement, the Company was required to pay a final payment fee of $1.9 million, equal to 6.6% of the aggregate amounts borrowed. In connection with entering into the agreement, the Company issued to the lenders and the placement agent warrants to purchase an aggregate of 7,678 shares of Trevena’s common stock. Warrants exercisable for an aggregate of 5,728 shares remain outstanding as of December 31, 2020. These warrants were exercisable upon issuance and have an exercise price of $5.8610 per share. The warrants may be exercised on a cashless basis and will terminate on the earlier of September 19, 2024 or the closing of a merger or consolidation transaction in which the Company is not the surviving entity. In connection with the draw of Term Loan B, the Company issued to the lenders and the placement agent additional warrants to purchase an aggregate of 34,961 shares of the Company’s common stock. These warrants have substantially the same terms as those noted above, have an exercise price of $10.6190 per share and an expiration date of December 23, 2025. In connection with draw of Term Loan C, the Company issued to the lenders and placement agent additional warrants to purchase an aggregate of 62,241 shares of the Company’s common stock. These warrants have substantially the same terms as those noted above and have an exercise price of $3.6150 per share and an expiration date of March 31, 2027. These detachable warrant instruments have qualified for equity classification and have been allocated upon the relative fair value of the base instrument and the warrants, according to the guidance of ASC 470-20-25-2. As of December 31, 2020, there are no borrowings outstanding attributable to Term Loans A, B, or C. Interest expense of $0.02 million and $0.6 million was recorded during the years ended December 31, 2020 and 2019, respectively. The Company incurred lender and third-party costs of $1.0 million related to the issuance of its term loans. Per ASU 2015 03, Interest-Imputation of Interest, debt discount and debt issuance costs are to be presented as a contra-liability to the debt on the balance sheet. These costs were amortized to interest expense over the life of the loans using the effective interest method. Immaterial amounts of debt discount and debt issuance cost were amortized to interest expense during the year ended December 31, 2020. A total of $0.1 million of debt discount and debt issuance costs were amortized to interest expense during the year ended December 31, 2019. The following table summarizes how the issuance of Term Loans A, B, and C are reflected on the balance sheet at December 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 2019 Gross proceeds ​ $ — ​ $ 3,167 Debt discount and debt issuance costs (1) ​ — ​ 1,870 Carrying value ​ — ​ 5,037 Current portion of loans payable, net ​ — ​ 5,037 Loans payable, net ​ $ — ​ $ — (1) Includes the final fee payment due upon last payment date of the amounts borrowed.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity
Stockholders' Equity	7. Stockholders’ Equity Equity Offerings Under its certificate of incorporation, the Company was authorized to issue up to 200,000,000 shares of common stock as of December 31, 2020 and December 31, 2019. The Company also was authorized to issue up to 5,000,000 shares of preferred stock as of December 31, 2020 and December 31, 2019. The Company is required, at all times, to reserve and keep available out of its authorized but unissued shares of common stock sufficient shares to effect the conversion of the shares of the preferred stock and all outstanding stock options and warrants. Registered Underwritten Public Offering ATM Programs On April 17, 2019, the Company entered into a Common Stock Sales Agreement with H.C. Wainwright & Co., LLC, or Wainwright, pursuant to which the Company may offer and sell through Wainwright, from time to time at the Company’s sole discretion, shares of its common stock, having an aggregate offering price of up to $50.0 million, or the HCW ATM Program. Sales of the shares of common stock are deemed to be “at-the-market offerings,” as defined in Rule 415 under the Securities Act. On December 31, 2020, the Company and Wainwright entered into Amendment No. 1 to Common Stock Sales Agreement, or the Amendment, to amend the Common Stock Sales Agreement to, among other things, update the reference to the registration statement pursuant to which the shares of Common Stock may be sold and to include an additional $50.0 million of shares of Common Stock in the HCW ATM Program. For the year ended December 31, 2020, the Company issued and sold approximately 39.3 million shares of common stock under the HCW ATM Program. The net offering proceeds to the Company in 2020 for sales under the HCW ATM Program were approximately $47.3 million after deducting related expenses, including commissions. As of December 31, 2020, and following the Amendment, there was approximately $50.0 million remaining available for future issuances under the HCW ATM Program. Registered Direct Offering and Concurrent Warrant Issuance On January 29, 2019, the Company entered into securities purchase agreements with two institutional investors wherein the Company agreed to sell to the investors an aggregate of 10,000,000 shares of its common stock, at an offering price of $1.00 per share, in a registered direct offering. The net proceeds to the Company from the offering were $9.2 million, after deducting fees and the expenses of the placement agent. Pursuant to a letter agreement dated January 28, 2019, the Company engaged Wainwright to act as its exclusive placement agent in connection with the issuance and sale of the shares. The Company paid Wainwright 7.0% of the aggregate gross proceeds in the offering and $50,000 for certain expenses, and it issued warrants to purchase 500,000 shares of common stock to certain designees of Wainwright. These warrants have a term of five years, are immediately exercisable and have an exercise price of $1.25 per share. During the year ended December 31, 2020, 327,500 of these warrants were exercised in a cashless exercise for 201,925 common shares. The warrants are classified as equity and were recorded at fair value as of the date of issuance on the Company’s Consolidated Balance Sheets and no further adjustments to their valuation are made. The letter agreement also includes indemnification obligations of the Company and other provisions customary for transactions of this nature. Equity Incentive Plans In 2008, the Company adopted the 2008 Equity Incentive Plan, as amended on February 29, 2008, January 7, 2010, July 8, 2010, December 10, 2010, June 23, 2011 and June 17, 2013, collectively, the 2008 Plan, that authorized the Company to grant restricted stock and stock options to eligible employees, directors and consultants to the Company. In 2013, the Company adopted the 2013 Equity Incentive Plan, as amended on May 14, 2014, collectively, 2013 Plan. The 2013 Plan became effective upon the Company’s entry into the underwriting agreement related to its IPO in January 2014 and, as of such date, no further grants were permitted under the 2008 Plan. The 2013 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance-based stock awards and other forms of equity compensation (collectively, stock awards), all of which may be granted to employees, including officers, non-employee directors and consultants of the Company. Additionally, the 2013 Plan provides for the grant of cash and stock-based performance awards. The 2013 Plan contains an “evergreen” provision, pursuant to which the number of shares of common stock available for issuance under the plan automatically increases on January 1 of each year beginning in 2015. On December 15, 2016, the Company adopted the Trevena, Inc. Inducement Plan, or the Inducement Plan, effective January 1, 2017, pursuant to which the Company reserved 500,000 shares of the Company’s common stock for issuance under the Inducement Plan. The Plan provides for nonstatutory stock options and restricted stock unit awards. The only persons eligible to receive grants of awards under the Inducement Plan are individuals who satisfy the standards for inducement grants under Nasdaq Marketplace Rule 5635(c)(4) and the related guidance under Nasdaq IM 5635-1, including individuals who were not previously an employee or director of the Company or are following a bona fide period of non-employment, in each case as an inducement material to such individual’s agreement to enter into employment with the Company. Under all Plans, the amount, terms of grants and exercisability provisions are determined by the board of directors or its designee. The term of the options may be up to 10 years, and options are exercisable in cash or as otherwise determined by the board of directors or its designee. Vesting generally occurs over a period of not greater than four years. For performance-based stock awards, the Company recognizes expense when achievement of the performance condition is probable, over the requisite service period. The estimated grant-date fair value of the Company’s share-based awards is amortized on a straight-line basis over the awards’ service periods. Share-based compensation expense recognized was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Research and development ​ $ 781 ​ $ 825 General and administrative ​ 2,497 ​ 2,407 Cost of goods sold ​ ​ 6 ​ ​ — Total stock-based compensation ​ $ 3,284 ​ $ 3,232 ​ Stock Options A summary of stock option activity and related information from January 1, 2019 through December 31, 2020 follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ Weighted ​ Remaining ​ ​ ​ ​ Average ​ Contractual ​ ​ Number of ​ Exercise ​ Term ​ ​ Shares ​ Price ​ (in years) Balance, January 1, 2019 8,265,207 ​ $ 3.99 6.99 Granted 1,033,000 ​ 1.10 ​ ​ Exercised (41,968) ​ 0.68 ​ ​ Forfeited/Cancelled (1,687,935) ​ (4.94) ​ ​ Balance, December 31, 2019 7,568,304 ​ $ 3.40 7.01 Granted 2,477,486 ​ 1.90 ​ ​ Exercised (197,640) ​ 0.68 ​ ​ Forfeited/Cancelled (283,631) ​ (3.33) ​ ​ Balance, December 31, 2020 9,564,519 ​ $ 3.07 7.17 Vested or expected to vest at December 31, 2020 9,564,519 ​ $ 3.07 7.17 Exercisable at December 31, 2020 5,536,713 ​ $ 3.88 5.94 ​ The intrinsic value of the options exercisable as of December 31, 2020 was $1.6 million, based on the Company’s closing stock price of $2.14 per share and a weighted average exercise price of $3.88 per share. The Company uses the Black-Scholes option-pricing model to estimate the fair value of stock options at the grant date. The Black-Scholes model requires the Company to make certain estimates and assumptions, including estimating the fair value of the Company’s common stock, assumptions related to the expected price volatility of the Company’s stock, the period during which the options will be outstanding, the rate of return on risk-free investments and the expected dividend yield for the Company’s stock. The per-share weighted average grant date fair value of the options granted to employees and directors during the years ended December 31, 2020 and 2019 was estimated at $1.48 and $0.86 per share, respectively, on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Expected term of options (in years) 6.1 6.1 Risk-free interest rate 0.6 % 1.9 % Expected volatility 97.3 % 98.9 % Dividend yield — % — % ​ The weighted average valuation assumptions were determined as follows: ● Risk-free interest rate: The Company based the risk-free interest rate on the interest rate payable on U.S. Treasury securities in effect at the time of grant for a period that is commensurate with the assumed expected option term. ● Expected term of options: Due to its lack of sufficient historical data, the Company estimates the expected life of its employee stock options using the “simplified” method, as prescribed in Staff Accounting Bulletin No. 107. ● Expected stock price volatility: The Company estimates the expected volatility based on the actual historical volatility of the Company’s stock price using daily closing prices over a period equal to the expected term of the associated award. Prior to January 1, 2018, the Company estimated the expected volatility based on actual historical volatility of the stock price of similar companies with publicly-traded equity securities. ● Expected annual dividend yield: The Company estimated the expected dividend yield based on consideration of its historical dividend experience and future dividend expectations. The Company has not historically declared or paid dividends to stockholders. Moreover, it does not intend to pay dividends in the future, but instead expects to retain any earnings to invest in the continued growth of the business. Accordingly, the Company assumed an expected dividend yield of 0.0% . ● Estimated forfeiture rate: The Company elected to record forfeitures upon occurrence, rather than utilizing an estimate. As of December 31, 2020, there was $4.4 million of total unrecognized compensation expense related to unvested stock options that will be recognized over the weighted average remaining period of 3.26 years. Restricted Stock Units During the year ended December 31, 2020, the Company granted 2,536,850 restricted stock units, or RSUs, to employees. The units vest annually over a four year period. The weighted average fair market value per RSU on the grant date was $2.11, which is equal to the closing price of the Company’s common stock on the date of the grant RSU-related expense is recognized on a straight-line basis over the vesting period. Upon vesting, these awards may be settled on a net-exercise basis to cover any required withholding tax with the remaining amount converted into an equivalent number of shares of common stock. There were 477,255 shares of common stock underlying vested RSUs that were withheld during the year ended December 31, 2020, based on the value of the RSU awards as determined by the Company’s closing stock price on the applicable vesting date. The shares withheld for taxes are again available for issuance under the plan. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ Number of ​ Grant Date ​ ​ Awards ​ Fair Value Non-vested at January 1, 2019 1,255,000 ​ $ 0.65 Granted 2,500,585 ​ 0.74 Vested (572,500) ​ 0.65 Forfeited/Cancelled (237,500) ​ 0.65 Non-vested at December 31, 2019 2,945,585 ​ $ 0.73 Granted 2,536,850 ​ 2.11 Vested (1,519,493) ​ 0.71 Forfeited (191,600) ​ 0.69 Non-vested at December 31, 2020 3,771,342 ​ $ 1.66 ​ For the years ended December 31, 2020 and 2019, the Company recorded $1.1 million and $0.5 million, respectively, in stock-based compensation expense related to RSUs, which is reflected in the statements of operations and comprehensive loss. As of December 31, 2020, there was $6.1 million of total unrecognized compensation expense related to unvested RSUs that will be recognized over the weighted average remaining period of 3.57 years. Shares Available for Future Grant At December 31, 2020, the Company has the following shares available to be granted: ​ ​ ​ ​ ​ ​ ​ Inducement ​ ​ 2013 Plan ​ Plan Available at December 31, 2019 4,394,301 205,000 Authorized 3,768,550 ​ — Granted (5,014,336) ​ — Shares withheld for taxes not issued ​ 477,255 ​ — Forfeited/Cancelled 427,731 ​ 47,500 Available at December 31, 2020 4,053,501 252,500 ​ Shares Reserved for Future Issuance At December 31, 2020, the Company has reserved the following shares of common stock for issuance: ​ ​ ​ Stock options outstanding under 2013 Plan 9,317,019 Restricted stock units outstanding under 2013 Plan 3,771,342 Shares reserved for future issuance under 2013 Plan 4,053,501 Stock options outstanding under Inducement Plan 247,500 Shares reserved for future issuance under Inducement Plan ​ 252,500 Shares reserved for future issuance under 2013 Employee Stock Purchase Plan 225,806 Warrants outstanding 295,591 Total shares of common stock reserved for future issuance 18,163,259 ​

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies.
Commitments and Contingencies	8. Commitments and Contingencies Leases The Company leases office space in Chesterbrook, Pennsylvania and equipment. The Company’s principal office is located at 955 Chesterbrook Boulevard, Chesterbrook, Pennsylvania, where the Company currently leases approximately 8,231 square feet of developed office space on the first floor and 40,565 square feet of developed office space on the second floor. The lease term for this space extends through May 2028. On October 11, 2018, the Company entered into an agreement with The Vanguard Group, Inc., or Vanguard, whereby Vanguard agreed to sublease the 40,565 square feet of space on the second floor for an initial term of 37 months. On October 2, 2020, Vanguard notified the Company that they exercised the first option to extend the sublease term for three years through November 30, 2024. Vanguard has a second option to extend the sublease term for an additional three years through November 30, 2027. The sublease provides for rent abatement for the first month of the term; thereafter, the rent payable to the Company by Vanguard under the sublease is (i) $0.50 less during months 2 through 13 of the sublease and (ii) in month 14 and thereafter of the sublease, $1.00 less than the base rent payable by the Company under its master lease with Chesterbrook Partners, L.P. Vanguard also is responsible for paying to the Company all tenant energy costs, annual operating costs, and annual tax costs attributable to the subleased space during the term of the sublease. Rent expense and associated sublease income are recorded in the Company’s statements of operations and comprehensive loss as other income (expense). Supplemental balance sheet information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 December 31, 2019 ​ Operating leases: ​ ​ ​ Operating lease right-of-use assets $ 5,119 $ 5,472 ​ Other current liabilities ​ ​ 696 ​ ​ 611 ​ Operating lease liabilities ​ ​ 7,097 ​ ​ 7,793 ​ Total operating lease liabilities ​ $ 7,793 ​ $ 8,404 ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance leases: ​ ​ ​ ​ ​ ​ ​ Property and equipment, at cost ​ $ 45 ​ $ 45 ​ Accumulated depreciation ​ ​ (34) ​ ​ (25) ​ Property and equipment, net ​ ​ 11 ​ ​ 20 ​ Other current liabilities ​ ​ 7 ​ ​ 9 ​ Other long-term liabilities ​ ​ 4 ​ ​ 11 ​ Total finance lease liabilities ​ $ 11 ​ $ 20 ​ ​ The components of lease expense were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, ​ ​ 2020 2019 Operating lease costs: ​ ​ ​ ​ ​ ​ ​ Operating lease rental expense ​ ​ $ 1,256 ​ $ 1,187 Other income ​ ​ ​ (1,195) ​ ​ (1,263) Total operating lease costs ​ ​ $ 61 ​ $ (76) ​ ​ ​ ​ ​ ​ ​ ​ Finance lease costs: ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ ​ $ 9 ​ $ 11 Interest on lease liabilities ​ ​ ​ 1 ​ ​ 2 Total finance lease costs ​ ​ $ 10 ​ $ 13 ​ Supplemental cash flow information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ 2020 2019 Cash paid for amounts included in the measurement of lease liabilities ​ ​ Operating cash flows from operating leases ​ $ (179) ​ $ (167) Operating cash flows from finance leases ​ — ​ — Financing cash flows from finance leases ​ ​ (10) ​ (12) ​ ​ Our operating lease liabilities will mature, as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Financing Leases 2021 ​ $ 1,376 ​ $ 8 2022 ​ 1,401 ​ 4 2023 ​ 1,425 ​ — 2024 ​ 1,450 ​ — 2025 and beyond ​ 5,136 ​ — Total minimum lease payments ​ $ 10,788 ​ $ 12 Interest Expense ​ ​ (2,995) ​ ​ (1) Lease liability ​ $ 7,793 ​ $ 11 ​ Per the terms of our sublease, we expect the following inflows (in thousands): ​ ​ ​ ​ ​ Sublease 2021 ​ $ 1,098 2022 ​ 1,118 2023 ​ ​ 1,139 2024 ​ 996 2025 and beyond ​ — Total minimum lease payments ​ $ 4,351 ​ Weighted average lease term and discount rates are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Weighted average remaining lease term (years) ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 7 ​ ​ 8 Finance leases ​ ​ 1 ​ ​ 2 Weighted average discount rate ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 9.2% ​ ​ 9.2% Finance leases ​ ​ 6.5% ​ ​ 6.5% ​ The Company had no deferred rent at December 31, 2020 or 2019 related to its facility leases. Legal Proceedings In October and November 2018, the Company and certain current and former officers and directors were sued in three purported class actions filed in the U.S. District Court for the Eastern District of Pennsylvania, or the EDPA, alleging violations of the federal securities laws. In January 2019, the three lawsuits were consolidated into one action, and on May 29, 2019, the District Court appointed a group of five individual investors as lead plaintiffs. A consolidated amended complaint was filed on August 2, 2019, alleging, among other things, that the Company and two former officers made false and misleading statements regarding the Company’s business, operations, and prospects, including certain statements made relating to the Company’s End-of-Phase 2 meeting with the FDA, and certain statements concerning top-line results from the Company’s Phase 3 studies. The plaintiffs seek, among other remedies, unspecified damages, attorneys’ fees and other costs, and unspecified equitable or injunctive relief. On August 28, 2020, the EDPA granted in part and denied in part the defendants’ motion to dismiss. On October 2, 2020, the Company and the individual defendants filed their answer to the amended complaint, denying all liability. On February 11, 2021, the parties agreed in principle to a settlement, which is subject to final documentation and approval by the Court. The Company and the individual defendants do not acknowledge any wrongdoing as part of the settlement, and a monetary payment of $8.5 million will be made to the plaintiffs and their counsel, all of which will be funded by the Company’s insurance carriers. The Company has recorded the $8.5 million estimated settlement liability and the $8.5 million estimated insurance recovery in its 2020 financial statements. The Company continues to believe that the claims are without merit, and if necessary, the Company intends to vigorously defend itself and its former officers against the allegations. In December 2018, a shareholder derivative action was filed on behalf of the Company and against certain current and former officers and directors in the EDPA, and in February 2019, two additional, similar shareholder derivative actions were filed in the U.S. District Court for the District of Delaware. A fourth similar shareholder derivative action was filed in the EDPA in September 2019, and a fifth, similar derivative action was filed in the EDPA in November 2019. A similar sixth derivative action was filed in the EDPA in September 2020. These cases, which involve facts similar to the consolidated securities lawsuits, assert claims against the individual defendants for, among other things, breach of fiduciary duty, waste of corporate assets, violations of the federal securities laws, and unjust enrichment, and they make a number of demands, including for monetary damages and other equitable and injunctive relief. Some of the derivative actions have been stayed in favor of the consolidated securities lawsuits. The Company recorded in the fourth quarter of 2020 an estimated liability of $0.5 million and a corresponding insurance recovery of the same amount.

Product Revenue

Product Revenue	12 Months Ended
	Dec. 31, 2020
Revenue
Product Revenue	9. Product Revenue Performance Obligation The Company’s performance obligation is the supply of finished pharmaceutical products to its customers. The Company’s customers consist of major wholesale distributors. The Company’s customer contracts generally consist of both a master agreement, which is signed by the Company and its customer, and a customer submitted purchase order, which is governed by the terms and conditions of the master agreement. Revenue is recognized when the Company transfers control of its products to the customer, which occurs at a point-in-time, upon delivery. The Company offers standard payment terms to its customers and has elected the practical expedient to not adjust the promised amount of consideration for the effects of a significant financing, since the period between when the Company transfers the product to the customer and when the customer pays for that product is one year or less. Taxes collected from customers relating to product revenue and remitted to governmental authorities are excluded from revenues. The consideration amounts due from customers as a result of product revenue are subject to variable consideration, as described further below. The Company offers standard product warranties which provide assurance that the product will function as expected and in accordance with specifications. Customers cannot purchase warranties separately and these warranties do not give rise to a separate performance obligation. The Company permits the return of product under certain circumstances, mainly upon at or near product expiration, instances of shipping errors or where product is damaged in transit. The Company accrues for the customer’s right to return as part of its variable consideration. See below for further details. Variable Consideration The Company includes an estimate of variable consideration in its transaction price at the time of sale, when control of the product transfers to the customer. Variable consideration includes distributor chargebacks, prompt payment (cash) discounts, distribution service fees and product returns. The Company assesses whether or not an estimate of its variable consideration is constrained and has determined that the constraint does not apply, since it is probable that a significant reversal in the amount of cumulative revenue will not occur in the future when the uncertainty associated with the variable consideration is subsequently resolved. The Company’s estimates for variable consideration are adjusted as required at each reporting period for specific known developments that may result in a change in the amount of total consideration it expects to receive. Distributor Chargebacks When a product that is subject to a contractual price agreement is sold to a third party, the difference between the price paid to the Company by the wholesaler and the price under the specific contract is charged back to the Company by the wholesaler. Utilizing this information, the Company estimates a chargeback percentage for each product and records an allowance for chargebacks as a reduction to revenue when the Company records sales of the products. We reduce the chargeback allowance when a chargeback request from a wholesaler is processed. Reserves for distributor chargebacks are included in accounts receivable, net on the consolidated balance sheet. Prompt Payment (Cash) Discounts The Company provides customers with prompt payment discounts which may result in adjustments to the price that is invoiced for the product transferred, in the case that payments are made within a defined period. The Company’s prompt payment discount reserves are based on actual net sales and contractual discount rates. Reserves for prompt payment discounts are included in accounts receivable, net on the consolidated balance sheet. Distribution Service Fees The Company pays distribution service fees to its customers based on a fixed percentage of the product price. These fees are not in exchange for a distinct good or service and therefore are recognized as a reduction of the transaction price. The Company reserves for these fees based on actual net sales, contractual fee rates negotiated with the customer and the mix of the products in the distribution channel that remain subject to fees. Reserves for distribution service fees are included in accounts receivable, net on the consolidated balance sheet. Product Returns Generally, the Company’s customers have the right to return any unopened product during the eighteen 18 six 6 twelve 12 Six 6 two forty-eight 48 The Company recognizes the amount of expected returns as a refund liability, representing the obligation to return the customer’s consideration. Since the returns primarily consist of expired and short dated products that will not be resold, the Company does not record a return asset for the right to recover the goods returned by the customer at the time of the initial sale (when recognition of revenue is deferred due to the anticipated return). Accrued product return estimates are recorded in accrued expenses and other current liabilities on the consolidated balance sheet. Concentration of Revenue Two of the Company’s largest customers account for 100% of total product revenue for the year ended December 31, 2020. The following table presents a rollforward of the major categories of sales-related deductions included in trade receivable allowances for the year ended December 31, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Sales Discounts Chargebacks Fee for Service Balance, January 1, 2020 ​ $ — ​ $ — ​ $ — Provision related to current period sales ​ ​ 2 ​ ​ 5 ​ ​ 10 Adjustment related to prior period sales ​ — ​ — ​ — Credit or payments made during the period ​ ​ — ​ ​ — ​ ​ — Balance, December 31, 2020 ​ $ 2 ​ $ 5 ​ $ 10 ​

License Revenue

License Revenue	12 Months Ended
	Dec. 31, 2020
License Revenue
License Revenue	10. License Revenue License and Commercialization Agreement with Pharmbio Korea Inc. In April 2018, the Company entered into an exclusive license agreement with Pharmbio Korea Inc., or Pharmbio, for the development and commercialization of OLINVYK for the management of moderate to severe acute pain in South Korea. Under the terms of the agreement, the Company received an upfront, non-refundable cash payment of $3.0 million (less applicable withholding taxes of $0.5 million) in June 2018, and will receive a cash commercial milestone of up to $0.5 million if OLINVYK is approved in South Korea and tiered royalties on product sales in South Korea ranging from high single digits to 20%, less applicable withholding taxes. As part of the agreement, the Company also granted Pharmbio an option to manufacture OLINVYK, on a non-exclusive basis, for the development and commercialization of the product in South Korea, subject to a separate arrangement to be entered into if Pharmbio exercises the option. The license agreement is terminable by Pharmbio for any reason upon 180 days written notice. In accordance with the terms of the agreement, Pharmbio is solely responsible for all development and regulatory activities in South Korea. The parties have formed a Joint Development Committee with equal representation from the Company and Pharmbio to provide overall coordination and oversight of the development of OLINVYK in South Korea. The parties also agreed to form a Joint Manufacturing and Commercialization Committee at least six months prior to the anticipated date of regulatory approval of OLINVYK in South Korea to provide overall coordination and oversight of the manufacture and commercialization of OLINVYK in South Korea. License Agreement with Jiangsu Nhwa Pharmaceutical Co. Ltd. In April 2018, the Company also entered into an exclusive license agreement with Jiangsu Nhwa Pharmaceutical Co. Ltd., or Nhwa, for the development and commercialization of OLINVYK for the management of moderate to severe acute pain in China. Under the terms of this agreement, the Company received an upfront, non-refundable cash payment of $2.5 million (less applicable withholding taxes of $0.3 million) in July 2018. In August 2020, the Company received a milestone payment of $3.0 million (less applicable withholding taxes of $0.3 million), that became payable by Nhwa upon FDA approval of OLINVYK. The Company is also eligible to receive a cash milestone payment of $3.0 million, subject to Chinese withholding taxes, upon regulatory approval of OLINVYK in China, up to an additional $6.0 million of commercialization milestone payments based on product sales levels in China, and a ten percent royalty on all net product sales in China, less applicable withholding taxes. As part of the agreement, the Company also granted Nhwa an option to manufacture OLINVYK, on an exclusive basis in China, for the development and commercialization of the product in China. In the second quarter of 2018, Nhwa elected to exercise this manufacturing option and the Company and Nhwa expect to enter into a separate agreement for such services. The license agreement is terminable by Nhwa for any reason upon 180 days written notice. In accordance with the terms of the agreement, Nhwa is solely responsible for all development and regulatory activities in China. The parties have formed a Joint Development Committee with equal representation from the Company and Nhwa to provide overall coordination and oversight of the development of OLINVYK in China. The parties also agreed to form a Joint Manufacturing and Commercialization Committee at least six months prior to the anticipated date of regulatory approval of OLINVYK in China to provide overall coordination and oversight of the manufacture and commercialization of OLINVYK in China. For the year ended December 31, 2020 and 2019, license revenue in the accompanying statements of operations and comprehensive loss is comprised of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 ​ 2019 Pharmbio Korea Inc. ​ $ — ​ $ — Jiangsu Nhwa Pharmaceutical Co. Ltd. ​ ​ 3,000 ​ ​ 31 Total license revenues ​ $ 3,000 ​ $ 31 ​

Restructuring Charges

Restructuring Charges	12 Months Ended
	Dec. 31, 2020
Restructuring Charges
Restructuring Charges	11. Restructuring Charges On November 8, 2018, upon the approval of the Company's Board of Directors, the Company announced a restructuring of approximately one- third The following table summarizes the restructuring balances at December 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Balance, January 1 ​ $ — ​ $ 1,419 Current year restructuring costs ​ ​ — ​ ​ — Payment of employee severance costs ​ — ​ (1,419) Balance, December 31 ​ $ — ​ $ — ​

Net Loss Per Common Share

Net Loss Per Common Share	12 Months Ended
	Dec. 31, 2020
Net Loss Per Common Share
Net Loss Per Common Share	12. Net Loss Per Common Share The following table sets forth the computation of basic and diluted net loss per share for the periods indicated (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Basic and diluted net loss per common share calculation: ​ ​ Net loss ​ $ (29,369) ​ $ (24,871) Net loss attributable to common stockholders ​ $ (29,369) ​ $ (24,871) Weighted average common shares outstanding ​ 127,623,859 ​ 91,677,963 Net loss per share of common stock - basic and diluted ​ $ (0.23) ​ $ (0.27) ​ The following outstanding securities at December 31, 2020 and 2019 have been excluded from the computation of diluted weighted shares outstanding, as they would have been anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Options outstanding 9,564,519 7,568,304 RSUs outstanding ​ 3,771,342 ​ 2,945,585 Warrants 295,591 623,091 Total 13,631,452 11,136,980 ​

Comprehensive Income (Loss)

Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2020
Comprehensive Income (Loss)
Comprehensive Income (Loss)	13. Comprehensive Income (Loss) The following table presents changes in the components of accumulated other comprehensive income or loss, net of tax (in thousands): ​ ​ ​ ​ Balance, January 1, 2019 $ (9) Net unrealized gain on marketable securities ​ 9 Balance, December 31, 2019 $ — Net unrealized gain on marketable securities ​ — Balance, December 31, 2020 ​ $ — ​ There were no reclassifications out of accumulated other comprehensive income or loss as well as no tax effect for all periods presented.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Taxes
Income Taxes	14. Income Taxes The income tax provision for the years ended December 31, 2020 and 2019 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Current: ​ ​ ​ ​ ​ ​ Foreign ​ $ 300 ​ $ — Federal ​ ​ — ​ ​ — State ​ — ​ — Total ​ 300 ​ — Deferred ​ ​ Foreign ​ ​ — ​ ​ — Federal ​ ​ — ​ ​ — State ​ — ​ — Total ​ — ​ — Total income tax provision (benefit) ​ $ 300 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets and liabilities reflect the net effects of net operating losses, or NOLs, and tax credit carryovers and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Realization of the deferred tax assets is contingent on future taxable income and based upon the level of historical losses, management has concluded that the deferred tax assets do not meet the more-likely-than-not threshold for realizability. Accordingly, a full valuation allowance continues to be recorded against the Company's deferred tax assets as of December 31, 2020 and 2019. The Company’s valuation allowance increased by $5.9 million and $9.0 million for the years ended December 31, 2020 and 2019, respectively. Significant components of the Company’s net deferred tax assets as of December 31, 2020 and 2019 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Deferred tax assets: ​ ​ ​ ​ ​ ​ NOLs ​ $ 25,949 ​ $ 22,033 Research and development credits ​ 14,920 ​ 14,138 Research and development expenses capitalized for tax purposes ​ 93,812 ​ 92,350 Equity-based compensation ​ ​ 4,130 ​ ​ 4,586 Deferred rent ​ 772 ​ 847 Depreciation ​ 246 ​ 162 Other temporary differences ​ 730 ​ 538 Total deferred tax assets ​ 140,559 ​ 134,654 Deferred tax liabilities: ​ ​ Prepaid expenses ​ (119) ​ (86) Total deferred tax liabilities ​ (119) ​ (86) Net deferred tax assets ​ 140,440 ​ 134,568 Less valuation allowance ​ (140,440) ​ (134,568) Net deferred tax asset ​ $ — ​ $ — ​ A reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes as reflected in the financial statements is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Percent of pre-tax income: U.S. federal statutory income tax rate 21.0 % 21.0 % Permanent Differences 1.0 % — % State taxes, net of federal benefit 4.8 % 8.3 % Research and development credit 2.6 % 3.4 % Withholding Tax ​ (1.0) % — % Stock compensation ​ (6.9) % — % Other (2.3) % 3.3 % Change in valuation allowance (20.2) % (36.0) % Effective income tax rate (1.0) % — % ​ As of December 31, 2020, the Company had U.S. federal and state NOLs of $90.2 million and $88.8 million, respectively, that begin to expire starting in 2027. As of December 31, 2020, the Company had federal research and development tax credit carryforwards of $14.9 million that begin to expire in 2027. Net operating loss and tax credit carryforwards may become subject to annual limitations in the event of certain cumulative changes in the ownership interest of significant stockholders over a three-year period in excess of 50%, as defined by Sections 382 and 383 of the Internal Revenue Code as well as similar state provisions. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The Company files income tax returns in the U.S. and the Commonwealth of Pennsylvania. Tax years for 2017 and thereafter are open and potentially subject to examination by the federal and state taxing authorities. The Company is currently not under examination by the Internal Revenue Service or any other jurisdictions for any tax years. To the extent the Company utilizes any tax attributes from a tax period that may otherwise be closed due to statute expiration, the Internal Revenue Service, state tax authorities, or other governing parties may still adjust the tax attributes upon their examination of the future period in which the attribute was utilized. There are no uncertain tax positions recorded for any federal or state positions. The Company’s policy is to record interest and penalties related to tax matters in income tax expense.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2020
Employee Benefit Plan
Employee Benefit Plan	15. Employee Benefit Plan The Company sponsors a 401(k) defined contribution plan for its employees. Employee contributions are voluntary. The Company matches employee contributions in an amount equal to 100% of the first 3% of eligible compensation and 50% of the next 2% of eligible compensation, and such employer contributions are immediately vested. During each of the years ended December 31, 2020 and 2019, the Company provided matching contributions of $0.2 million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or U.S. GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the ASC and Accounting Standards Updates, or ASUs, of the FASB. The Company’s functional currency is the U.S. dollar.
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 amounts reported in the financial statements and accompanying notes. Management used significant estimates in the following areas, among others: stock-based compensation expense, the determination of the fair value of stock-based awards, the fair value of common stock warrants, the accounting for research and development costs, accrued expenses and the recoverability of the Company’s net deferred tax assets and related valuation allowance. The Company is also subject to certain contingent liabilities with respect to existing or potential claims, lawsuits and other proceedings. The Company accrues liabilities when it considers probable that future costs will be incurred and such costs can be reasonably estimated, and recognizes an asset for proceeds from related insurance claims that are considered probable of recovery. The financial data and other information disclosed in these notes are not necessarily indicative of the results to be expected for any future year or period. The Company bases its estimates on historical experience and also on assumptions that it believes are reasonable, however, actual results could significantly differ from those results.
Cash and Cash Equivalents and Marketable Securities	Cash, Cash Equivalents and Marketable Securities The Company considers all highly liquid investments that have maturities of three months or less when acquired to be cash equivalents. Cash equivalents are valued at cost, which approximates their fair market value. The Company maintains a portion of its cash and cash equivalent balances in money market mutual funds that may invest substantially all of their assets in U.S. government agency securities and U.S. Treasury securities. The Company classifies its marketable securities as “available-for-sale,” pursuant to ASC Topic 320, Investments—Debt and Equity Securities The fair value of the Company’s investments is determined based on observable market quotes or valuation models using assessments of counterparty credit worthiness, credit default risk of underlying security and overall capital market liquidity. The Company reviews unrealized losses associated with available-for-sale securities to determine the classification as “temporary” or “other-than-temporary” impairment. A temporary impairment results in an unrealized loss being recorded in other comprehensive income (loss). If a decline in the fair value is considered other-than-temporary, based on available evidence, the unrealized loss is transferred from other comprehensive income (loss) to the statement of operations. The Company considers various factors in determining the classification, including the length of time and extent to which the fair value has been less than the Company’s cost basis, the financial condition and near-term prospects of the issuer or investee, and the Company’s ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. Realized gains (losses) are included in interest income (expense) in the statement of operations and comprehensive income (loss) on a specific identification basis.
Restricted Cash	Restricted Cash The Company maintains $1.3 million as collateral under a letter of credit for the Company’s facility lease obligations in Chesterbrook, Pennsylvania. The Company has recorded this deposit and accumulated interest thereon as restricted cash on its balance sheet.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amount of the Company’s financial instruments, which include cash and cash equivalents, marketable securities, restricted cash, accounts payable and accrued expenses approximate their fair values, given their short-term nature. The carrying amount of the Company’s loans payable at December 31, 2019 is the nominal value of the loan payable, net of unamortized debt discount and deferred charges. The Company had no loans payable at December 31, 2020. The nominal value approximates fair value because the interest rate is reflective of the rate the Company could obtain on debt with similar terms and conditions. Certain of the Company’s common stock warrants are carried at fair value, as disclosed in Note 3. The Company has evaluated the estimated fair value of financial instruments using available market information and management’s estimates. The use of different market assumptions and/or estimation methodologies could have a significant effect on the estimated fair value amounts. See Note 3 for additional information.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents, marketable securities and restricted cash. The Company’s investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. The Company has no off-balance sheet concentrations of credit risk such as foreign currency exchange contracts, option contracts or other hedging arrangements.
Property and Equipment	Property and Equipment Property and equipment consists of computer and laboratory equipment, software, office equipment, furniture, manufacturing equipment and leasehold improvements and is recorded at cost. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Upon disposal, retirement or sale, the related cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the results of operations. Property and equipment are depreciated on a straight-line basis over their estimated useful lives. The Company uses a life of three years for computer equipment and five years for laboratory equipment, office equipment, furniture, manufacturing equipment and software. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the asset. The Company reviews long-lived assets when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets. $0.1 million of impairment losses were recorded during the year ended December 31, 2019. No impairment losses were recorded during the year ended December 31, 2020.
Leases	Leases At the commencement of a lease, the Company recognizes a liability to make lease payments and an asset representing the right to use the underlying asset during the lease term. The lease liability is measured at the present value of lease payments over the lease term, including variable fees that are known or subject to a minimum floor. The lease liability includes lease component fees, while non-lease component fees are expensed as incurred for all asset classes. When a contract excludes an implicit rate, the Company utilizes an incremental borrowing rate based on information available at the lease commencement date including lease term and geographic region. The initial valuation of the right-of-use, or ROU, asset includes the initial measurement of the lease liability, lease payments made in advance of the lease commencement date, and initial direct costs incurred by the Company and excludes lease incentives. Leases with an initial term of 12 months or less are classified as short-term leases and are not recorded on the balance sheet. The lease expense for short-term leases is recognized on a straight-line basis over the lease term. The Company tests for impairment of the ROU assets whenever circumstances indicate that the carrying amount of the asset may not be recoverable.
Common Stock Warrants	Common Stock Warrants Freestanding warrants that are related to the purchase of common stock are classified as liabilities and recorded at fair value regardless of the timing of the redemption feature or the redemption price or the likelihood of redemption. These warrants are subject to re-measurement at each balance sheet date and any change in fair value is recognized as a component of change in fair value of warrant liability in the statements of operations and comprehensive loss. The Company will continue to adjust the liability for changes in fair value until the earlier of the exercise or expiration of the warrants. The warrants are classified as Level 3 liabilities. The value of these warrants was immaterial as of December 31, 2020 and 2019. In addition, in connection with entering into loan agreements, the Company has issued warrants to purchase shares of the Company’s common stock. These detachable warrant instruments qualify for equity classification and have been allocated upon the relative fair value of the base instrument and the warrant. See Note 6 and Note 7 for additional information.
Segment Information	Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company’s chief operating decision maker is the chief executive officer. The Company and the chief executive officer view the Company’s operations and manage its business as one operating segment. All long-lived assets of the Company reside in the United States.
Revenue	Revenue In accordance with FASB’s ASC 606, Revenue from Contracts with Customers, or ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, it performs the following five steps: (i) (ii) (iii) (iv) (v) The Company applies the five-step model to contracts when it determines that it is probable it will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. See Note 9 and Note 10, respectively, for a full discussion of the Company’s product revenue and license revenue.
Research and Development	Research and Development Research and development costs are charged to expense as incurred. Research and development costs include, but are not limited to, personnel expenses, clinical trial supplies, fees for clinical trial services, manufacturing costs, consulting costs, and allocated overhead, including rent, equipment depreciation, and utilities. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as subject enrollment, clinical site activations or information provided to the Company by its vendors with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid or accrued research and development expense, as the case may be. As part of the process of preparing its financial statements, the Company is required to estimate its expenses resulting from its obligations under contracts with vendors, clinical research organizations and consultants, and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company’s objective is to reflect the appropriate trial expenses in its financial statements by matching those expenses with the period in which services are performed and efforts are expended. The Company may account for these expenses according to the progress of the trial as measured by subject progression and the timing of various aspects of the trial. The Company determines accrual estimates through financial models taking into account discussion with applicable personnel and outside service providers as to the progress or state of consummation of trials, or the services completed. During the course of a clinical trial, the Company adjusts its clinical expense recognition if actual results differ from its estimates. The Company makes estimates of its accrued expenses as of each balance sheet date based on the facts and circumstances known to it at that time. The Company’s clinical trial accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in it reporting amounts that are too high or too low for any particular period. For the years ended December 31, 2020 and 2019, there were no material adjustments to the Company’s prior period estimates of accrued expenses for clinical trials.
Stock-Based Compensation	Stock-Based Compensation The Company has equity incentive plans under which various types of equity-based awards including, but not limited to, incentive stock options, non-qualified stock options, and restricted stock unit awards, may be granted to employees, non-employee directors, and non-employee consultants. At December 31, 2020, the Company had two stock-based compensation plans, which are more fully described in Note 7. The Company also has an inducement plan under which various types of equity-based awards, including non-qualified stock options and restricted stock awards, may be granted to new employees. The Company has applied the fair value recognition provisions of Financial Accounting Standards Board Accounting Standards Codification Topic 718, Compensation — Stock Compensation, to account for stock-based compensation for employees. The Company recognizes compensation expense for all stock-based awards based on the estimated grant-date fair values. For restricted stock unit awards to employees, the fair value is based on the closing price of the Company’s common stock on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as expense on a straight-line basis over the requisite service period. The fair value of stock options is determined using the Black-Scholes option pricing model. The Company utilizes a dividend yield of zero based on the fact that the Company has never paid cash dividends and has no current intention of paying cash dividends. The Company elected an accounting policy to record forfeitures as they occur. For stock awards that vest based on performance conditions (e.g., achievement of certain milestones), expense is recognized when it is probable that the conditions will be met. See Note 7 for a discussion of the assumptions used by the Company in determining the grant date fair value of options granted under the Black-Scholes option pricing model, as well as a summary of the stock option activity under the Company’s stock-based compensation plan for all years presented.
Income Taxes	Income Taxes Income taxes are recorded in accordance with ASC Topic 740, Income Taxes The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position, as well as consideration of the available facts and circumstances. To date, the Company has not taken any uncertain tax position or recorded any reserves, interest or penalties. On December 22, 2017, the U.S. government enacted comprehensive tax legislation informally titled the Tax Cuts and Jobs Act of 2017, or the Tax Act. Additionally, the SEC staff issued SAB 118, which provides guidance on accounting for the effects of the Tax Act. See Note 14.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Comprehensive income (loss) relates to unrealized investment gains or losses on the Company’s marketable securities for all periods presented.
Basic and Diluted Net Loss Per Share of Common Stock	Basic and Diluted Net Loss Per Share of Common Stock The Company’s basic net loss per share is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. The diluted net loss per common share is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. Because the impact of these items is anti-dilutive during periods of net loss, there was no difference between basic and diluted net loss per share of common stock for all periods presented.
Recent Accounting Pronouncements	Recently Adopted Accounting Standards In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement Fair Value Measurement Recent Accounting Standards Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value of Financial Instruments
Schedule of cash, cash equivalents and marketable securities	The following table presents the Company’s cash, cash equivalents, restricted cash, and marketable securities as of December 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Adjusted ​ Unrealized ​ Unrealized ​ ​ ​ ​ Cash and Cash ​ Restricted ​ Marketable ​ ​ Cost Gains Losses Fair Value Equivalents Cash Securities Cash ​ $ 6,100 ​ $ — ​ $ — ​ $ 6,100 ​ $ 4,790 ​ $ 1,310 ​ $ — Level 1 (1): ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ 104,613 ​ — ​ — ​ 104,613 ​ 104,613 ​ — ​ — U.S. treasury securities ​ — ​ — ​ — ​ — ​ — ​ — ​ — Subtotal ​ 104,613 ​ — ​ — ​ 104,613 ​ 104,613 ​ — ​ — Level 2 (2): ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ — ​ — ​ — ​ — ​ — ​ — ​ — Total ​ $ 110,713 ​ $ — ​ $ — ​ $ 110,713 ​ $ 109,403 ​ $ 1,310 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ Adjusted ​ Unrealized ​ Unrealized ​ ​ ​ ​ Cash and Cash ​ Restricted ​ Marketable ​ Cost Gains Losses Fair Value Equivalents Cash Securities Cash ​ $ 9,302 ​ $ — ​ $ — ​ $ 9,302 ​ $ 7,993 ​ $ 1,309 ​ $ — Level 1 (1): ​ ​ ​ ​ ​ ​ ​ Money market funds ​ 18,306 ​ — ​ — ​ 18,306 ​ 18,306 ​ — ​ — U.S. treasury securities ​ ​ 5,996 ​ — ​ — ​ 5,996 ​ 2,496 ​ — ​ 3,500 Subtotal ​ 24,302 ​ — ​ — ​ 24,302 ​ 20,802 ​ — ​ 3,500 Level 2 (2): ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ 3,510 ​ — ​ — ​ 3,510 ​ 3,510 ​ — ​ — Total ​ $ 37,114 ​ $ — ​ $ — ​ $ 37,114 ​ $ 32,305 ​ $ 1,309 ​ $ 3,500 (1) The fair value of Level 1 securities is estimated based on quoted prices in active markets for identical assets or liabilities. (2) The fair value of Level 2 securities is estimated based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term on the assets or liabilities.

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2020
Property and Equipment, net
Schedule of property and equipment	Property and equipment consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated ​ ​ ​ ​ ​ ​ ​ ​ Useful ​ December 31, ​ Life in Years 2020 2019 Computers and software ​ 3 5 ​ $ 476 ​ $ 480 Office equipment and furniture ​ 5 ​ 721 ​ 706 Manufacturing equipment ​ 5 ​ 10 ​ 10 Leasehold improvements ​ 10 ​ 3,082 ​ 3,082 Leased assets ​ 5 ​ 45 ​ 45 Total property and equipment ​ ​ ​ 4,334 ​ 4,323 Less accumulated depreciation and amortization ​ ​ ​ (2,081) ​ (1,618) Property and equipment, net ​ ​ ​ ​ $ 2,253 ​ $ 2,705

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Accrued Expenses and Other Current Liabilities
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Compensation and benefits ​ $ 2,919 ​ $ 1,786 Commercial expenses ​ ​ 605 ​ ​ — Legal expenses ​ ​ 784 ​ ​ 86 Pharmaceutical development expenses ​ 413 ​ 445 Accrued interest ​ — ​ 18 Other accrued expenses and other current liabilities ​ 447 ​ 68 Total accrued expenses and other current liabilities ​ $ 5,168 ​ $ 2,403

Loans Payable (Tables)

Loans Payable (Tables)	12 Months Ended
	Dec. 31, 2020
Loans Payable
Schedule of debt	The following table summarizes how the issuance of Term Loans A, B, and C are reflected on the balance sheet at December 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 2019 Gross proceeds ​ $ — ​ $ 3,167 Debt discount and debt issuance costs (1) ​ — ​ 1,870 Carrying value ​ — ​ 5,037 Current portion of loans payable, net ​ — ​ 5,037 Loans payable, net ​ $ — ​ $ — (1) Includes the final fee payment due upon last payment date of the amounts borrowed.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity
Schedule of share-based compensation expense recognized	The estimated grant-date fair value of the Company’s share-based awards is amortized on a straight-line basis over the awards’ service periods. Share-based compensation expense recognized was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Research and development ​ $ 781 ​ $ 825 General and administrative ​ 2,497 ​ 2,407 Cost of goods sold ​ ​ 6 ​ ​ — Total stock-based compensation ​ $ 3,284 ​ $ 3,232
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ Weighted ​ Remaining ​ ​ ​ ​ Average ​ Contractual ​ ​ Number of ​ Exercise ​ Term ​ ​ Shares ​ Price ​ (in years) Balance, January 1, 2019 8,265,207 ​ $ 3.99 6.99 Granted 1,033,000 ​ 1.10 ​ ​ Exercised (41,968) ​ 0.68 ​ ​ Forfeited/Cancelled (1,687,935) ​ (4.94) ​ ​ Balance, December 31, 2019 7,568,304 ​ $ 3.40 7.01 Granted 2,477,486 ​ 1.90 ​ ​ Exercised (197,640) ​ 0.68 ​ ​ Forfeited/Cancelled (283,631) ​ (3.33) ​ ​ Balance, December 31, 2020 9,564,519 ​ $ 3.07 7.17 Vested or expected to vest at December 31, 2020 9,564,519 ​ $ 3.07 7.17 Exercisable at December 31, 2020 5,536,713 ​ $ 3.88 5.94
Schedule of weighted-average assumptions:	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Expected term of options (in years) 6.1 6.1 Risk-free interest rate 0.6 % 1.9 % Expected volatility 97.3 % 98.9 % Dividend yield — % — %
Schedule of changes in the status of non-vested RSU	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ Number of ​ Grant Date ​ ​ Awards ​ Fair Value Non-vested at January 1, 2019 1,255,000 ​ $ 0.65 Granted 2,500,585 ​ 0.74 Vested (572,500) ​ 0.65 Forfeited/Cancelled (237,500) ​ 0.65 Non-vested at December 31, 2019 2,945,585 ​ $ 0.73 Granted 2,536,850 ​ 2.11 Vested (1,519,493) ​ 0.71 Forfeited (191,600) ​ 0.69 Non-vested at December 31, 2020 3,771,342 ​ $ 1.66
Schedule of shares available to be granted under equity incentive plans	At December 31, 2020, the Company has the following shares available to be granted: ​ ​ ​ ​ ​ ​ ​ Inducement ​ ​ 2013 Plan ​ Plan Available at December 31, 2019 4,394,301 205,000 Authorized 3,768,550 ​ — Granted (5,014,336) ​ — Shares withheld for taxes not issued ​ 477,255 ​ — Forfeited/Cancelled 427,731 ​ 47,500 Available at December 31, 2020 4,053,501 252,500
Schedule of shares of common stock reserved/available	At December 31, 2020, the Company has reserved the following shares of common stock for issuance: ​ ​ ​ Stock options outstanding under 2013 Plan 9,317,019 Restricted stock units outstanding under 2013 Plan 3,771,342 Shares reserved for future issuance under 2013 Plan 4,053,501 Stock options outstanding under Inducement Plan 247,500 Shares reserved for future issuance under Inducement Plan ​ 252,500 Shares reserved for future issuance under 2013 Employee Stock Purchase Plan 225,806 Warrants outstanding 295,591 Total shares of common stock reserved for future issuance 18,163,259

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies.
Schedule of balance sheet information related to leases	Supplemental balance sheet information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 December 31, 2019 ​ Operating leases: ​ ​ ​ Operating lease right-of-use assets $ 5,119 $ 5,472 ​ Other current liabilities ​ ​ 696 ​ ​ 611 ​ Operating lease liabilities ​ ​ 7,097 ​ ​ 7,793 ​ Total operating lease liabilities ​ $ 7,793 ​ $ 8,404 ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance leases: ​ ​ ​ ​ ​ ​ ​ Property and equipment, at cost ​ $ 45 ​ $ 45 ​ Accumulated depreciation ​ ​ (34) ​ ​ (25) ​ Property and equipment, net ​ ​ 11 ​ ​ 20 ​ Other current liabilities ​ ​ 7 ​ ​ 9 ​ Other long-term liabilities ​ ​ 4 ​ ​ 11 ​ Total finance lease liabilities ​ $ 11 ​ $ 20 ​
Schedule of components of lease expense	The components of lease expense were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, ​ ​ 2020 2019 Operating lease costs: ​ ​ ​ ​ ​ ​ ​ Operating lease rental expense ​ ​ $ 1,256 ​ $ 1,187 Other income ​ ​ ​ (1,195) ​ ​ (1,263) Total operating lease costs ​ ​ $ 61 ​ $ (76) ​ ​ ​ ​ ​ ​ ​ ​ Finance lease costs: ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ ​ $ 9 ​ $ 11 Interest on lease liabilities ​ ​ ​ 1 ​ ​ 2 Total finance lease costs ​ ​ $ 10 ​ $ 13
Schedule of supplemental cash flow information	Supplemental cash flow information related to leases was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ 2020 2019 Cash paid for amounts included in the measurement of lease liabilities ​ ​ Operating cash flows from operating leases ​ $ (179) ​ $ (167) Operating cash flows from finance leases ​ — ​ — Financing cash flows from finance leases ​ ​ (10) ​ (12)
Schedule of maturities of operating lease liabilities	​ ​ Our operating lease liabilities will mature, as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Financing Leases 2021 ​ $ 1,376 ​ $ 8 2022 ​ 1,401 ​ 4 2023 ​ 1,425 ​ — 2024 ​ 1,450 ​ — 2025 and beyond ​ 5,136 ​ — Total minimum lease payments ​ $ 10,788 ​ $ 12 Interest Expense ​ ​ (2,995) ​ ​ (1) Lease liability ​ $ 7,793 ​ $ 11 ​
Schedule of maturities of financing lease liabilities	​ ​ Our operating lease liabilities will mature, as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Financing Leases 2021 ​ $ 1,376 ​ $ 8 2022 ​ 1,401 ​ 4 2023 ​ 1,425 ​ — 2024 ​ 1,450 ​ — 2025 and beyond ​ 5,136 ​ — Total minimum lease payments ​ $ 10,788 ​ $ 12 Interest Expense ​ ​ (2,995) ​ ​ (1) Lease liability ​ $ 7,793 ​ $ 11
Schedule of expected sublease inflows	Per the terms of our sublease, we expect the following inflows (in thousands): ​ ​ ​ ​ ​ Sublease 2021 ​ $ 1,098 2022 ​ 1,118 2023 ​ ​ 1,139 2024 ​ 996 2025 and beyond ​ — Total minimum lease payments ​ $ 4,351
Schedule of weighted average lease term and discount rates	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Weighted average remaining lease term (years) ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 7 ​ ​ 8 Finance leases ​ ​ 1 ​ ​ 2 Weighted average discount rate ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 9.2% ​ ​ 9.2% Finance leases ​ ​ 6.5% ​ ​ 6.5%

Product Revenue (Tables)

Product Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue
Schedule of major categories of sales-related deductions included in trade receivable allowances	The following table presents a rollforward of the major categories of sales-related deductions included in trade receivable allowances for the year ended December 31, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Sales Discounts Chargebacks Fee for Service Balance, January 1, 2020 ​ $ — ​ $ — ​ $ — Provision related to current period sales ​ ​ 2 ​ ​ 5 ​ ​ 10 Adjustment related to prior period sales ​ — ​ — ​ — Credit or payments made during the period ​ ​ — ​ ​ — ​ ​ — Balance, December 31, 2020 ​ $ 2 ​ $ 5 ​ $ 10

License Revenue (Tables)

License Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue
Schedule of license revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 ​ 2019 Pharmbio Korea Inc. ​ $ — ​ $ — Jiangsu Nhwa Pharmaceutical Co. Ltd. ​ ​ 3,000 ​ ​ 31 Total license revenues ​ $ 3,000 ​ $ 31

Restructuring Charges (Tables)

Restructuring Charges (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring Charges
Schedule of restructuring balances	The following table summarizes the restructuring balances at December 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Balance, January 1 ​ $ — ​ $ 1,419 Current year restructuring costs ​ ​ — ​ ​ — Payment of employee severance costs ​ — ​ (1,419) Balance, December 31 ​ $ — ​ $ —

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2020
Net Loss Per Common Share
Schedule of computation of basic and diluted net loss per share	The following table sets forth the computation of basic and diluted net loss per share for the periods indicated (in thousands, except share and per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2020 2019 Basic and diluted net loss per common share calculation: ​ ​ Net loss ​ $ (29,369) ​ $ (24,871) Net loss attributable to common stockholders ​ $ (29,369) ​ $ (24,871) Weighted average common shares outstanding ​ 127,623,859 ​ 91,677,963 Net loss per share of common stock - basic and diluted ​ $ (0.23) ​ $ (0.27)
Schedule of outstanding securities excluded from the computation of diluted weighted shares outstanding as they would have been anti-dilutive	​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Options outstanding 9,564,519 7,568,304 RSUs outstanding ​ 3,771,342 ​ 2,945,585 Warrants 295,591 623,091 Total 13,631,452 11,136,980

Comprehensive Income (Loss) (Ta

Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2020
Comprehensive Income (Loss)
Schedule of components of accumulated other comprehensive income or loss, net of tax	The following table presents changes in the components of accumulated other comprehensive income or loss, net of tax (in thousands): ​ ​ ​ ​ Balance, January 1, 2019 $ (9) Net unrealized gain on marketable securities ​ 9 Balance, December 31, 2019 $ — Net unrealized gain on marketable securities ​ — Balance, December 31, 2020 ​ $ —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Taxes
Schedule of income tax provision	The income tax provision for the years ended December 31, 2020 and 2019 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Current: ​ ​ ​ ​ ​ ​ Foreign ​ $ 300 ​ $ — Federal ​ ​ — ​ ​ — State ​ — ​ — Total ​ 300 ​ — Deferred ​ ​ Foreign ​ ​ — ​ ​ — Federal ​ ​ — ​ ​ — State ​ — ​ — Total ​ — ​ — Total income tax provision (benefit) ​ $ 300 ​ $ — ​ ​ ​ ​ ​ ​ ​
Schedule of significant components of the Company's deferred tax assets	Significant components of the Company’s net deferred tax assets as of December 31, 2020 and 2019 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Deferred tax assets: ​ ​ ​ ​ ​ ​ NOLs ​ $ 25,949 ​ $ 22,033 Research and development credits ​ 14,920 ​ 14,138 Research and development expenses capitalized for tax purposes ​ 93,812 ​ 92,350 Equity-based compensation ​ ​ 4,130 ​ ​ 4,586 Deferred rent ​ 772 ​ 847 Depreciation ​ 246 ​ 162 Other temporary differences ​ 730 ​ 538 Total deferred tax assets ​ 140,559 ​ 134,654 Deferred tax liabilities: ​ ​ Prepaid expenses ​ (119) ​ (86) Total deferred tax liabilities ​ (119) ​ (86) Net deferred tax assets ​ 140,440 ​ 134,568 Less valuation allowance ​ (140,440) ​ (134,568) Net deferred tax asset ​ $ — ​ $ —
Schedule of reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes as reflected in the financial statements	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2020 2019 Percent of pre-tax income: U.S. federal statutory income tax rate 21.0 % 21.0 % Permanent Differences 1.0 % — % State taxes, net of federal benefit 4.8 % 8.3 % Research and development credit 2.6 % 3.4 % Withholding Tax ​ (1.0) % — % Stock compensation ​ (6.9) % — % Other (2.3) % 3.3 % Change in valuation allowance (20.2) % (36.0) % Effective income tax rate (1.0) % — %

Organization and Description _2

Organization and Description of the Business (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)
Organization and Description of the Business
Number of operating segments | segment	1
Accumulated deficit	$ 442,514	$ 413,145
Net loss	$ 29,369	$ 24,871

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)itemsegment$ / shares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2018$ / shares
Investments
Marketable securities		$ 3,500
Restricted Cash
Letters of credit	$ 1,300
Property and Equipment
Impairment of property and equipment	$ 0	$ 108
Segment Information
Number of operating segments | segment	1
Stock-Based Compensation
Number of stock-based compensation plans | item	2
Dividend yield	0.00%
Basic and diluted net loss per common share calculation:
Difference between basic and diluted net loss per share of Common Stock (in dollars per share) | $ / shares	$ 0	$ 0	$ 0
Computer equipment
Property and Equipment
Estimated useful life	P3Y
Laboratory equipment, office equipment, furniture and software
Property and Equipment
Estimated useful life	P5Y

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Hierarchy Table (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair value
Transfers between Level 2 and Level 3	$ 0	$ 0
Adjusted cost
Fair value
Cash and Cash Equivalents, Fair Value Disclosure	6,100	9,302
Assets, Fair Value Disclosure	110,713	37,114
Fair Value
Fair value
Cash and Cash Equivalents, Fair Value Disclosure	6,100	9,302
Assets, Fair Value Disclosure	110,713	37,114
Chesterbrook, Pennsylvania
Fair value
Letter of credit collateral	1,300
Cash and Cash Equivalents | Fair Value
Fair value
Cash and Cash Equivalents, Fair Value Disclosure	4,790	7,993
Assets, Fair Value Disclosure	109,403	32,305
Restricted Cash | Fair Value
Fair value
Cash and Cash Equivalents, Fair Value Disclosure	1,310	1,309
Assets, Fair Value Disclosure	1,310	1,309
Marketable Securities | Fair Value
Fair value
Assets, Fair Value Disclosure		3,500
Level 1 | Adjusted cost
Fair value
Investments, Fair Value Disclosure	104,613	24,302
Level 1 | Fair Value
Fair value
Investments, Fair Value Disclosure	104,613	24,302
Level 1 | Money market funds | Adjusted cost
Fair value
Investments, Fair Value Disclosure	104,613	18,306
Level 1 | Money market funds | Fair Value
Fair value
Investments, Fair Value Disclosure	104,613	18,306
Level 1 | U.S. treasury securities | Adjusted cost
Fair value
Investments, Fair Value Disclosure		5,996
Level 1 | U.S. treasury securities | Fair Value
Fair value
Investments, Fair Value Disclosure		5,996
Level 1 | Cash and Cash Equivalents | Fair Value
Fair value
Investments, Fair Value Disclosure	104,613	20,802
Level 1 | Cash and Cash Equivalents | Money market funds | Fair Value
Fair value
Investments, Fair Value Disclosure	$ 104,613	18,306
Level 1 | Cash and Cash Equivalents | U.S. treasury securities | Fair Value
Fair value
Investments, Fair Value Disclosure		2,496
Level 1 | Marketable Securities | Fair Value
Fair value
Investments, Fair Value Disclosure		3,500
Level 1 | Marketable Securities | U.S. treasury securities | Fair Value
Fair value
Investments, Fair Value Disclosure		3,500
Level 2 | U.S. government agency securities | Adjusted cost
Fair value
Investments, Fair Value Disclosure		3,510
Level 2 | U.S. government agency securities | Fair Value
Fair value
Investments, Fair Value Disclosure		3,510
Level 2 | Cash and Cash Equivalents | U.S. government agency securities | Fair Value
Fair value
Investments, Fair Value Disclosure		$ 3,510

Property and Equipment, net (De

Property and Equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property and Equipment
Total property and equipment	$ 4,334	$ 4,323
Accumulated depreciation	(2,081)	(1,618)
Property and equipment, net	2,253	2,705
Depreciation and amortization expense	477	562
Computers and software
Property and Equipment
Total property and equipment	$ 476	480
Computers and software | Minimum
Property and Equipment
Estimated useful life	P3Y
Computers and software | Maximum
Property and Equipment
Estimated useful life	P5Y
Office equipment and furniture
Property and Equipment
Estimated useful life	P5Y
Total property and equipment	$ 721	706
Manufacturing equipment
Property and Equipment
Estimated useful life	P5Y
Total property and equipment	$ 10	10
Leasehold improvements
Property and Equipment
Estimated useful life	P10Y
Total property and equipment	$ 3,082	3,082
Leased Assets
Property and Equipment
Estimated useful life	P5Y
Total property and equipment	$ 45	$ 45

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Expenses and Other Current Liabilities
Compensation and benefits	$ 2,919	$ 1,786
Commercial expenses	605
Legal expenses	784	86
Pharmaceutical development expenses	413	445
Accrued interest		18
Other accrued expenses and other current liabilities	447	68
Total accrued expenses and other current liabilities	$ 5,168	$ 2,403

Loans Payable (Details)

Loans Payable (Details) $ / shares in Units, $ in Thousands	Mar. 02, 2020USD ($)	Sep. 30, 2014USD ($)tranche$ / sharesshares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)	Sep. 30, 2020$ / sharesshares	Mar. 31, 2017USD ($)	Dec. 31, 2015$ / sharesshares
Long Term Debt
Interest expense			$ 29	$ 931
Amortization of debt discount and issuance costs				100
Loan and security agreement
Long Term Debt
Maximum amount available		$ 35,000
Debt number of tranches | tranche		3
Gross proceeds						$ 28,500
Final payment fee	$ 1,900
Final payment fee percentage	6.60%
Term Loan A | Common Stock | Warrants
Long Term Debt
Number of shares that can be purchased upon exercise of warrants (in shares) | shares		7,678	5,728
Exercise price | $ / shares		$ 5.8610
Term Loan B | Common Stock | Warrants
Long Term Debt
Number of shares that can be purchased upon exercise of warrants (in shares) | shares							34,961
Exercise price | $ / shares							$ 10.6190
Term Loan C
Long Term Debt
Interest rate (as a percent)		6.98%
Term Loan C | Common Stock | Warrants
Long Term Debt
Number of shares that can be purchased upon exercise of warrants (in shares) | shares					62,241
Exercise price | $ / shares					$ 3.6150
Term Loans A and B
Long Term Debt
Interest rate (as a percent)		6.50%
Term Loans A, B, and C
Long Term Debt
Gross proceeds				3,167
Aggregate principal balance outstanding			$ 0
Interest expense			$ 20	$ 600
Debt discount and debt issuance costs		$ 1,000

Loans Payable Schedule of Debt

Loans Payable Schedule of Debt (Details) $ in Thousands	Dec. 31, 2019USD ($)
Long Term Debt
Current portion of loans payable, net	$ 5,037
Term Loans A, B, and C
Long Term Debt
Gross proceeds	3,167
Debt discount and debt issuance costs	1,870
Carrying value	5,037
Current portion of loans payable, net	$ 5,037

Stockholders' Equity - Equity O

Stockholders' Equity - Equity Offerings (Details)	Jan. 29, 2019USD ($)Institution$ / sharesshares	Jan. 28, 2019USD ($)$ / sharesshares	Aug. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)shares	Apr. 17, 2019USD ($)
Stockholders' Equity
Common stock authorized (in shares) | shares				200,000,000	200,000,000
Preferred stock authorized (in shares) | shares				5,000,000	5,000,000
Proceeds from Issuance of Common Stock				$ 101,010,000	$ 10,312,000
Issuance of common stock, net of issuance costs				$ 101,010,000	$ 9,965,000
Wainwright
Stockholders' Equity
Percentage of aggregate gross proceeds paid		7.00%
Expenses paid		$ 50,000
Warrants to purchase shares of common stock | shares		500,000
Warrants term		5 years
Exercise price (in dollars per share) | $ / shares		$ 1.25
Number of warrants exercised in a cashless exercise | shares				327,500
Common shares issued in conversion of warrants | shares				201,925
At-the-market sales facility - April 17, 2019 agreement | Maximum
Stockholders' Equity
Offering amount						$ 50,000,000
At-the-market sales facility - December 31, 2020 agreement
Stockholders' Equity
Offering amount				$ 50,000,000
Private Placement
Stockholders' Equity
Issuance of common stock (in shares) | shares	10,000,000
Offering price (in dollars per share) | $ / shares	$ 1
Issuance of common stock, net of issuance costs	$ 9,200,000
Number of institutional investors | Institution	2
Public Offering
Stockholders' Equity
Issuance of common stock (in shares) | shares			25,000,000
Offering price (in dollars per share) | $ / shares			$ 2.30
Issuance of common stock, net of issuance costs			$ 53,700,000
Time period for full exercise of option to purchase additional shares			30 days
CW ATM Program
Stockholders' Equity
Issuance of common stock (in shares) | shares				39,300,000
Proceeds from Issuance of Common Stock				$ 47,300,000
Stock available for further issuance				$ 50,000,000

Stockholders' Equity - Equity I

Stockholders' Equity - Equity Incentive Plans (Details) - USD ($) $ in Thousands	Dec. 15, 2016	Dec. 31, 2020	Dec. 31, 2019
Equity Incentive Plans
Stock-based compensation		$ 3,284	$ 3,232
Research and Development Expense
Equity Incentive Plans
Stock-based compensation		781	825
General and Administrative Expense
Equity Incentive Plans
Stock-based compensation		2,497	$ 2,407
Cost of goods sold
Equity Incentive Plans
Stock-based compensation		$ 6
2008 Plan and 2013 Plan
Equity Incentive Plans
Authorized (in shares)	500,000
2008 Plan and 2013 Plan | Maximum
Equity Incentive Plans
Term of award		10 years
Vesting period		4 years

Stockholders' Equity - Options

Stockholders' Equity - Options Outstanding (Details) - Employee Stock Option - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Shares
Balance at the beginning of the period (in shares)	7,568,304	8,265,207
Granted (in shares)	2,477,486	1,033,000
Exercised (in shares)	(197,640)	(41,968)
Forfeited/Cancelled (in shares)	(283,631)	(1,687,935)
Balance at the end of the period (in shares)	9,564,519	7,568,304	8,265,207
Vested or expected to vest at the end of the period (in shares)	9,564,519
Exercisable at the end of the period (in shares)	5,536,713
Weighted-Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$ 3.40	$ 3.99
Granted (in dollars per share)	1.90	1.10
Exercised (in dollars per share)	0.68	0.68
Forfeited/Cancelled (in dollars per share)	(3.33)	(4.94)
Balance at the end of the period (in dollars per share)	3.07	$ 3.40	$ 3.99
Vested or expected to vest at the end of the period (in dollars per share)	3.07
Exercisable at the end of the period (in dollars per share)	$ 3.88
Intrinsic value of options exercisable	$ 1.6
Closing price of Company's stock (in dollars per share)	$ 2.14
Weighted Average Remaining Contractual Term
Options Outstanding at the end of the period	7 years 2 months 1 day	7 years 3 days	6 years 11 months 26 days
Vested or expected to vest at the end of the period	7 years 2 months 1 day
Exercisable at the end of the period	5 years 11 months 8 days

Stockholders' Equity - Assumpti

Stockholders' Equity - Assumptions Used (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Stockholders' Equity
Dividend yield	0.00%
Employee Stock Option
Stockholders' Equity
Weighted average grant date fair value (in dollars per share)	$ 1.48	$ 0.86
Expected term of options (in years)	6 years 1 month 6 days	6 years 1 month 6 days
Risk-free interest rate (as a percent)	0.60%	1.90%
Expected volatility (as a percent)	97.30%	98.90%
Dividend yield	0.00%	0.00%
Unrecognized compensation expense	$ 4.4
Weighted average remaining period for recognition of unrecognized compensation expense	3 years 3 months 3 days

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock Units (Details) - Restricted Stock Units - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Stockholders' Equity
Number of shares granted	2,536,850	2,500,585
Grant date fair value (in dollars per share)	$ 2.11	$ 0.74
Vesting period	4 years
Shares of common stock underlying vested RSUs withheld	477,255

Stockholders' Equity - Non-vest

Stockholders' Equity - Non-vested RSUs (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Weighted Average Grant Date Fair Value
Stock-based compensation	$ 3,284	$ 3,232
Restricted Stock Units
Number of Shares
Non-vested at beginning of period (in shares)	2,945,585	1,255,000
Granted (in shares)	2,536,850	2,500,585
Vested (in shares)	(1,519,493)	(572,500)
Forfeited/Cancelled	(191,600)	(237,500)
Non-vested at end of period (in shares)	3,771,342	2,945,585
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)	$ 0.73	$ 0.65
Granted (in dollars per share)	2.11	0.74
Vested (in dollars per share)	0.71	0.65
Forfeited (in dollars per share)	0.69	0.65
Non-vested at end of period (in dollars per share)	$ 1.66	$ 0.73
Stock-based compensation	$ 1,100	$ 500
Unrecognized compensation expense	$ 6,100
Weighted average remaining period for recognition of unrecognized compensation expense	3 years 6 months 25 days

Stockholders' Equity - Availabl

Stockholders' Equity - Available for Grant (Details)	12 Months Ended
	Dec. 31, 2020shares
2013 plan
Stockholders' Equity
Balance at the beginning of the period (in shares)	4,394,301
Authorized (in shares)	3,768,550
Granted (in shares)	(5,014,336)
Shares withheld for taxes not issued (in shares)	477,255
Forfeited/Cancelled (in shares)	427,731
Balance at the end of the period (in shares)	4,053,501
Inducement Plan
Stockholders' Equity
Balance at the beginning of the period (in shares)	205,000
Forfeited/Cancelled (in shares)	47,500
Balance at the end of the period (in shares)	252,500

Stockholders' Equity - Shares A

Stockholders' Equity - Shares Available for Future Issuance (Details) - shares	Dec. 31, 2020	Dec. 31, 2019
Stockholders' Equity
Employee stock purchase plan (in shares)	225,806
Warrants outstanding (in shares)	295,591
Total shares of common stock reserved for future issuance (in shares)	18,163,259
2013 plan
Stockholders' Equity
Stock options outstanding (in shares)	9,317,019
Shares available for future grant (in shares)	4,053,501	4,394,301
2013 plan | Restricted Stock Units
Stockholders' Equity
Stock options outstanding (in shares)	3,771,342
Inducement Plan
Stockholders' Equity
Stock options outstanding (in shares)	247,500
Shares available for future grant (in shares)	252,500	205,000

Commitments and Contingencies -

Commitments and Contingencies - Leases (Details) - Chesterbrook, Pennsylvania $ in Millions	Oct. 02, 2020	Oct. 11, 2018ft²$ / ft²	Dec. 31, 2020USD ($)ft²	Dec. 31, 2019USD ($)
Leases
Number of square feet of space leased on the first floor			8,231
Number of square feet of space leased on the second floor			40,565
Deferred rent | $			$ 0	$ 0
Sublease Agreements | Vanguard Group, Inc
Leases
Number of square feet of space being subleased on second floor		40,565
Initial term of sublease		37 months
Term of optional sublease extension	3 years
Term of second optional sublease extension		3 years
Amount per square foot less for rent during months 2 to 13 | $ / ft²		0.50
Amount per square foot for rent after month 14 | $ / ft²		1

Commitments and Contingencies_2

Commitments and Contingencies - Balance sheet information related to leases (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases
Operating lease right-of-use assets	$ 5,119	$ 5,472
Operating lease liabilities - Current	$ 696	$ 611
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	trvn:LeaseLiabilityCurrent	trvn:LeaseLiabilityCurrent
Operating lease liabilities - Noncurrent	$ 7,097	$ 7,793
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	trvn:LeaseLiabilityNoncurrent	trvn:LeaseLiabilityNoncurrent
Lease Liability	$ 7,793	$ 8,404
Property and equipment, at cost	4,334	4,323
Accumulated depreciation	(2,081)	(1,618)
Property and equipment, net	2,253	2,705
Finance lease liabilities - Current	$ 7	$ 9
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	trvn:LeaseLiabilityCurrent	trvn:LeaseLiabilityCurrent
Finance lease liabilities - Noncurrent	$ 4	$ 11
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	trvn:LeaseLiabilityNoncurrent	trvn:LeaseLiabilityNoncurrent
Lease Liability	$ 11	$ 20
Finance leased assets
Leases
Property and equipment, at cost	45	45
Accumulated depreciation	(34)	(25)
Property and equipment, net	$ 11	$ 20

Commitments and Contingencies_3

Commitments and Contingencies - Components of lease expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating lease costs:
Operating lease rental expense	$ 1,256	$ 1,187
Other income	(1,195)	(1,263)
Total operating lease costs	61	(76)
Finance lease costs:
Amortization of right-of-use assets	9	11
Interest on lease liabilities	1	2
Total finance lease costs	$ 10	$ 13

Commitments and Contingencies_4

Commitments and Contingencies - Cash flow information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies.
Operating cash flows from operating leases	$ (179)
Operating cash flows from operating leases, pre-adoption		$ (167)
Financing cash flows from finance leases	$ (10)	(12)
Financing cash flows from finance leases, pre-adoption		$ (12)

Commitments and Contingencies_5

Commitments and Contingencies - Lease liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Operating Leases
2021	$ 1,376
2022	1,401
2023	1,425
2024	1,450
2025 and beyond	5,136
Total minimum lease payments	10,788
Interest Expense	(2,995)
Lease Liability	7,793	$ 8,404
Financing Leases
2021	8
2022	4
Total minimum lease payments	12
Interest Expense	(1)
Lease Liability	11	$ 20
Sublease
2021	1,098
2022	1,118
2023	1,139
2024	996
Total minimum lease payments	$ 4,351

Commitments and Contingencies_6

Commitments and Contingencies - Lease term and discount rates (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020
Commitments and Contingencies.
Weighted average remaining lease term - Operating leases		7 years
Weighted average remaining lease term - Finance leases		1 year
Weighted average discount rate - Operating leases		9.20%
Weighted average discount rate - Finance leases		6.50%
Weighted average remaining lease term - Operating leases	8 years
Weighted average remaining lease term - Finance leases	2 years
Weighted average discount rate - Operating leases	9.20%
Weighted average discount rate - Finance leases	6.50%

Commitments and Contingencies_7

Commitments and Contingencies - Legal Proceedings (Details) $ in Thousands	Feb. 11, 2021USD ($)	Aug. 02, 2019employee	May 29, 2019item	Feb. 28, 2019lawsuit	Jan. 31, 2019lawsuit	Nov. 30, 2018lawsuit	Dec. 31, 2020USD ($)
Legal Proceedings
Estimated settlement liability							$ 9,000
Insurance recovery							$ 9,000
Class Actions In Eastern District Of Pennsylvania | Pending Litigation
Legal Proceedings
Number of claims | lawsuit					3	3
Number of claims after consolidation | lawsuit					1
Number of investors appointed | item			5
Number of former officers | employee		2
Monetary payement to be made to the plaintiff	$ 8,500
Estimated settlement liability	8,500
Insurance recovery	$ 8,500
Shareholder Derivative Actions | Pending Litigation
Legal Proceedings
Number of claims | lawsuit				2

Product Revenue (Details)

Product Revenue (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)customer
Sales Discounts
Provision related to current period sales	$ 2
Balance	2
Chargebacks
Provision related to current period sales	5
Balance	5
Fee for Service
Provision related to current period sales	10
Balance	$ 10
Product revenue | Revenue Benchmark | Customer Concentration Risk
Revenue
Number of customers | customer	2
Concentration risk percentage	100.00%
OLINVYK
Product Returns
Time period that customers have right to return unopened product	18 months
Time period prior to labeled expiration date that customers have right to return unopened product	6 months
Time period after labeled expiration date that customers have right to return unopened product	12 months
Time period after product launch that customers have right to return product from initial purchase	6 months
Product shelf life	48 months
OLINVYK | Minimum
Product Returns
Time period to evaluate historical sales	2 years
OLINVYK | Maximum
Product Returns
Time period to evaluate historical sales	3 years

License Revenue (Details)

License Revenue (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Aug. 31, 2020	Apr. 30, 2018	Dec. 31, 2020	Dec. 31, 2019
Licensing Arrangements
Total revenue			$ 3,069	$ 31
Pharmbio Korea Inc
Licensing Arrangements
Upfront payment		$ 3,000
Withholding taxes		$ 500
Time period for written notice to terminate license agreement		180 days
Pharmbio Korea Inc | Minimum
Licensing Arrangements
Time period to form a committee prior to the anticipated date of regulatory approval		6 months
Pharmbio Korea Inc | Maximum
Licensing Arrangements
Commercialization milestone payments		$ 500
Royalties on product sales, percentage		20.00%
Jiangsu Nhwa Pharmaceutical Co Ltd | Minimum
Licensing Arrangements
Time period to form a committee prior to the anticipated date of regulatory approval		6 months
Jiangsu Nhwa Pharmaceutical Co Ltd | Licensing agreements
Licensing Arrangements
Upfront payment	$ 3,000	$ 2,500
Withholding taxes	$ 300	$ 300
Time period for written notice to terminate license agreement			180 days
Milestone payment upon regulatory approval in China			$ 3,000
Milestone payment upon sales targets reached in China			$ 6,000
Royalty percentage on net product sales in China after milestones met			10.00%
License revenue
Licensing Arrangements
Total revenue			$ 3,000	$ 31

Restructuring Charges (Details)

Restructuring Charges (Details) $ in Thousands	Nov. 08, 2018employee	Dec. 31, 2018USD ($)	Dec. 31, 2019USD ($)
Summary of restructuring balances
Beginning balance			$ 1,419
Payment of employee severance costs			$ (1,419)
Ending balance		$ 1,419
Employee Severance
Restructuring Charges
Number of positions eliminated, percent	33.33%
Number of positions eliminated | employee	14
Total costs related to the restructuring		$ 1,400

Net Loss Per Common Share (Deta

Net Loss Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Basic and diluted net loss per common share calculation:
Net loss	$ (29,369)	$ (24,871)
Net loss attributable to common stockholders	$ (29,369)	$ (24,871)
Weighted average common shares outstanding (in shares)	127,623,859	91,677,963
Net loss per share of common stock, basic and diluted (in dollars per share)	$ (0.23)	$ (0.27)
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	13,631,452	11,136,980
Employee Stock Option
Basic and diluted net loss per common share calculation:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	9,564,519	7,568,304
Restricted Stock Units
Basic and diluted net loss per common share calculation:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	3,771,342	2,945,585
Warrants
Basic and diluted net loss per common share calculation:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	295,591	623,091

Comprehensive Income (Loss) (De

Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Comprehensive Loss
Beginning Balance	$ 30,078	$ 41,526
Ending Balance	104,068	30,078
Reclassifications out of accumulated other comprehensive income or loss, net of tax	0	0
Tax effect	$ 0	0
Accumulated Other Comprehensive Income (Loss)
Other Comprehensive Loss
Beginning Balance		(9)
Net unrealized gains (loss) on marketable securities		$ 9

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Taxes
Increase in valuation allowance	$ 5.9	$ 9
U.S. federal statutory income tax rate	21.00%	21.00%

Income Taxes - Income Tax Provi

Income Taxes - Income Tax Provision (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Current:
Foreign	$ 300
Total	300
Total income tax provision (benefit)	$ 300

Income Taxes - Deferred Taxes (

Income Taxes - Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
NOLs	$ 25,949	$ 22,033
Research and development credits	14,920	14,138
Research and development expenses capitalized for tax purposes	93,812	92,350
Equity-based compensation	4,130	4,586
Deferred rent	772	847
Depreciation	246	162
Other temporary differences	730	538
Total deferred tax assets	140,559	134,654
Deferred tax liabilities:
Prepaid expenses	(119)	(86)
Total deferred tax liabilities	(119)	(86)
Net deferred tax assets	140,440	134,568
Less valuation allowance	(140,440)	(134,568)
Net deferred tax asset	$ 0	$ 0

Income Taxes - Effective Tax Ra

Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Percent of pre-tax income:
U.S. federal statutory income tax rate	21.00%	21.00%
Permanent Differences	1.00%	0.00%
State taxes, net of federal benefit	4.80%	8.30%
Research and development credit	2.60%	3.40%
Withholding Tax	(1.00%)	0.00%
Stock compensation	(6.90%)	0.00%
Other	(2.30%)	3.30%
Change in valuation allowance	(20.20%)	(36.00%)
Effective income tax rate	(1.00%)	0.00%
U.S. federal
Operating loss carryforwards
Net operating loss carryforwards	$ 90.2
State Jurisdiction
Operating loss carryforwards
Tax credit carryforwards	88.8
Research Tax Credit Carryforward | U.S. federal
Operating loss carryforwards
Tax credit carryforwards	$ 14.9

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Employee Benefit Plan
Employer matching contribution for employee's contributions of the first 3% of eligible compensation	100.00%
Percentage of eligible compensation, matched 100% by employer	3.00%
Employer matching contribution for employee's contributions of the next 2% of eligible compensation	50.00%
Percentage of eligible compensation, matched 50% by employer	2.00%
Company's matching contributions to the plan	$ 0.2