Concert Pharmaceuticals (CNCE) 10-Q 5 May 22 2022 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2022	May 02, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	001-36310
Entity Registrant Name	CONCERT PHARMACEUTICALS, INC.
Entity Incorporation, State	DE
Entity Tax Identification Number	20-4839882
Entity Address, Street	65 Hayden Avenue
Entity Address, Suite	Suite 3000N
Entity Address, City	Lexington
Entity Address, State	MA
Entity Address, Postal Zip Code	02421
City Area Code	781
Local Phone Number	860-0045
Title of each class	Common Stock, par value $0.001 per share
Trading Symbol(s)	CNCE
Name of each exchange on which registered	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 Common Stock, Shares Outstanding		36,329,342
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001367920
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 59,363	$ 141,636
Investments, available for sale	49,643	0
Marketable equity securities	899	1,463
Interest receivable	251	0
Deferred offering costs	0	15
Accounts receivable	744	218
Prepaid expenses and other current assets	3,868	6,997
Total current assets	114,768	150,329
Property and equipment, net	5,015	5,242
Restricted cash	1,157	1,157
Other assets	2	3
Operating lease right-of-use asset, long-term	8,469	8,585
Total assets	129,411	165,316
Current liabilities:
Accounts payable	2,755	2,606
Accrued expenses and other liabilities	11,111	12,359
Lease liability, current portion	1,216	1,155
Total current liabilities	15,082	16,120
Accrued expenses, net of current portion	0	28
Deferred revenue, long-term	7,595	7,595
Lease liability, net of current portion	13,574	13,910
Warrant liabilities, long-term (Note 13)	16,594	15,438
Total liabilities	52,845	53,091
Commitments (Note 11)
Stockholders’ equity:
Preferred stock, $0.001 par value per share; 5,000,000 shares authorized; 32,500 shares designated as Series X1; 13,997 shares of Series X1 issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	0	0
Common stock, $0.001 par value per share; 100,000,000 shares authorized; 35,153,943 and 34,939,628 shares issued and 34,953,342 and 34,739,027 shares outstanding as of March 31, 2022 and December 31, 2021, respectively	34	34
Additional paid-in capital	463,876	461,765
Accumulated other comprehensive loss	(118)	(76)
Accumulated deficit	(387,226)	(349,498)
Total stockholders’ equity	76,566	112,225
Total liabilities and stockholders’ equity	$ 129,411	$ 165,316

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	35,153,943	34,939,628
Common stock, shares outstanding (in shares)	34,953,342	34,739,027
Series X1 Preferred Stock
Preferred stock, shares issued (in shares)	32,500	32,500
Preferred stock, shares outstanding (in shares)	13,997	13,997

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue:
Revenue	$ 0	$ 5
Operating expenses:
Research and development	30,489	18,500
General and administrative	5,539	5,485
Total operating expenses	36,028	23,985
Loss from operations	(36,028)	(23,980)
Investment income	20	25
Unrealized (loss) gain on marketable equity securities	(564)	1,286
Unrealized loss on warrant liabilities	(1,156)	0
Net loss	(37,728)	(22,669)
Other comprehensive loss:
Unrealized loss on investments, available for sale	(42)	(16)
Comprehensive loss	$ (37,770)	$ (22,685)
Net loss per share applicable to common stockholders - basic (in dollars per share)	$ (1.03)	$ (0.67)
Net loss per share applicable to common stockholders - diluted (in dollars per share)	$ (1.03)	$ (0.67)
Weighted-average number of common shares used in net loss per share attributable to common stockholders - basic (in shares)	36,687	33,894
Weighted-average number of common shares used in net loss per share attributable to common stockholders - diluted (in shares)	36,687	33,894

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	In Treasury	Additional paid-in capital	Accumulated other comprehensive loss	Accumulated deficit
Beginning balance at Dec. 31, 2020	$ 131,162	$ 0	$ 31		$ 400,636	$ (58)	$ (269,447)
Beginning balance (in shares) at Dec. 31, 2020		0	32,063,000	(200,000)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options	89				89
Exercise of stock options (in shares)			10,000
Release of restricted stock units (in shares)			136,000
Unrealized loss on investments, available for sale	(16)					(16)
Stock-based compensation expense	3,431				3,431
Proceeds from at-the-market offering, net of issuance costs	2,042				2,042
Proceeds from at-the-market offering, net of issuance costs (in shares)			165,000
Net loss	(22,669)						(22,669)
Ending balance at Mar. 31, 2021	114,039	$ 0	$ 31		406,198	(74)	(292,116)
Ending balance (in shares) at Mar. 31, 2021		0	32,374,000	(200,000)
Beginning balance at Dec. 31, 2021	$ 112,225	$ 0	$ 34		461,765	(76)	(349,498)
Beginning balance (in shares) at Dec. 31, 2021		14,000	34,938,000	(200,000)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options (in shares)	0
Release of restricted stock units (in shares)			216,000
Unrealized loss on investments, available for sale	$ (42)					(42)
Stock-based compensation expense	2,111				2,111
Net loss	(37,728)						(37,728)
Ending balance at Mar. 31, 2022	$ 76,566	$ 0	$ 34		$ 463,876	$ (118)	$ (387,226)
Ending balance (in shares) at Mar. 31, 2022		14,000	35,154,000	(200,000)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (37,728)	$ (22,669)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	321	392
Stock-based compensation expense	2,111	3,431
Amortization of premiums on investments	172	29
Unrealized loss (gain) on marketable equity securities	564	(1,286)
Unrealized loss on warrant liabilities	1,156	0
Non-cash lease expense	116	84
Changes in operating assets and liabilities:
Accounts receivable	(526)	74
Deferred offering costs	15	0
Interest receivable	(251)	118
Prepaid expenses and other current assets	3,129	1,243
Other assets	1	19
Accounts payable	147	278
Accrued expenses and other liabilities	(1,276)	(2,206)
Operating lease liability	(275)	(221)
Net cash used in operating activities	(32,324)	(20,714)
Investing activities
Purchases of property and equipment	(92)	(92)
Purchases of investments	(49,857)	0
Maturities of investments	0	30,712
Net cash (used in) provided by investing activities	(49,949)	30,620
Financing activities
Proceeds from exercise of stock options	0	89
Proceeds from at-the-market offering, net of issuance costs	0	2,575
Net cash provided by financing activities	0	2,664
Net (decrease) increase in cash, cash equivalents and restricted cash	(82,273)	12,570
Cash, cash equivalents and restricted cash at beginning of period	142,793	78,359
Cash, cash equivalents and restricted cash at end of period	60,520	90,929
Supplemental cash flow information:
Purchases of property and equipment unpaid at period end	3	3
Cash paid included in measurement of lease liabilities	$ 764	$ 742

Nature of Business

Nature of Business	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Concert Pharmaceuticals, Inc., or the Company, was incorporated on April 12, 2006 as a Delaware corporation and has its operations based in Lexington, Massachusetts. The Company is a late-stage clinical biopharmaceutical company that is developing CTP-543, a Janus Kinase 1 and Janus Kinase 2 (JAK 1/2) inhibitor that it discovered through the application of its deuterated chemical entity platform, or DCE Platform ® . As discussed in detail in the “Overview” section in Part I, Item 2. of this Quarterly Report on Form 10-Q, the Company is evaluating CTP-543 in a Phase 3 clinical program for the treatment of alopecia areata, a serious autoimmune dermatological condition. Liquidity and Going Concern As of March 31, 2022, the Company had cash, cash equivalents and investments of $109.0 million and net working capital of $99.7 million. The Company has incurred cumulative net losses of $387.2 million since inception and requires capital to continue future development activities. The Company does not have any products approved for sale and has not generated any revenue from product sales. The Company has financed its operations primarily through the public offering and private placement of its equity, debt financing, funding from collaborations and patent assignments, asset sales and other arrangements. The Company expects its expenses to increase in connection with its ongoing activities, particularly as it conducts its Phase 3 clinical program of CTP-543 in alopecia areata and seeks marketing approval for CTP-543. For information regarding the Company’s recent equity financings, see Notes 12 and 13. The Company is subject to risks common to companies in the biotechnology industry, including, but not limited to, risks of failure or unsatisfactory results of nonclinical studies and clinical trials, the need to obtain additional financing to fund the future development of its pipeline, the need to obtain marketing approval for its product candidates, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development by competitors of technological innovations and ability to transition from pilot-scale manufacturing to large-scale production of products. Under Accounting Standards Codification, or ASC, Topic 205-40, Presentation of Financial Statements - Going Concern , management is required at each reporting period to evaluate whether there are conditions and events, considered in the aggregate, that raise substantial doubt about an entity's ability to continue as a going concern within one year after the date that the financial statements are issued. This evaluation initially does not take into consideration the potential mitigating effect of management’s plans that have not been fully implemented as of the date the financial statements are issued. When substantial doubt exists, management evaluates whether the mitigating effect of its plans sufficiently alleviates the substantial doubt about the entity’s ability to continue as a going concern. The mitigating effect of management's plans, however, is only considered if both (i) it is probable that the plans will be effectively implemented within one year after the date that the financial statements are issued and (ii) it is probable that the plans, when implemented, will mitigate the relevant conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. Generally, to be considered probable of being effectively implemented, the plans must have been approved by the entity’s board of directors before the date that the financial statements are issued. Successful completion of the Company’s development program and, ultimately, the attainment of profitable operations are dependent upon future events, including obtaining adequate financing to support the Company’s cost structure and operating plan. Management’s plans to alleviate its financing requirements include, among other things, pursuing one or more of the following steps to raise additional capital, none of which can be guaranteed or are entirely within the Company’s control: • raise funding through the sale of the Company’s common or preferred stock; • raise funding through debt financing; and • establish collaborations with potential partners to advance the Company’s product pipeline. Based on the Company’s current operating plan, management believes that its current cash, cash equivalents and investments will allow the Company to meet its liquidity requirements into the fourth quarter of 2022. The Company’s history of significant losses, its negative cash flows from operations, its limited liquidity resources currently on hand and its dependence on its ability to obtain additional financing to fund its operations after the current resources are exhausted, about which there can be no certainty, have resulted in management’s assessment that there is substantial doubt about the Company’s ability to continue as a going concern for a period of at least twelve months from the issuance date of this Quarterly Report on Form 10-Q. The accompanying condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business, and do not include any adjustments that may result from the outcome of this uncertainty. If the Company is unable to raise capital when needed or on acceptable terms, or if it is unable to procure collaboration arrangements to advance its programs, the Company would be forced to discontinue some of its operations or develop and implement a plan to further extend payables, reduce overhead or scale back its current operating plan until sufficient additional capital is raised to support further operations. There can be no assurance that such a plan would be successful.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation The condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring accruals and revisions of estimates, considered necessary for a fair presentation of the condensed consolidated financial statements have been included. Interim results for the three months ended March 31, 2022 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2022 or any other future period. The accompanying condensed consolidated financial statements reflect the accounts of the Company and its subsidiaries. All intercompany transactions between the Company and its subsidiaries have been eliminated. Management has determined that the Company operates in one segment: the development of pharmaceutical products on its own behalf or in collaboration with others. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and the accompanying notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 filed with the Securities and Exchange Commission, or SEC, on March 3, 2022. Unless otherwise indicated, all amounts in the following tables are in thousands except share and per share amounts. Use of Estimates and Summary of Significant Accounting Policies The preparation of the consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenue, expenses and the disclosure of contingent assets and liabilities and the Company’s ability to continue as a going concern. In preparing the consolidated financial statements, management used estimates in the following areas, among others: revenue recognition; prepaid and accrued research and development expenses; stock-based compensation expense; fair value of warrant liabilities; and the evaluation of the existence of conditions and events that raise substantial doubt regarding the Company’s ability to continue as a going concern. Actual results could differ from those estimates. During the three months ended March 31, 2022, there have been no material changes to the significant accounting policies previously disclosed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021. Recently Adopted Accounting Pronouncements In August 2020, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity . ASU 2020-06 simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts in an entity’s own stock, by eliminating the cash conversion and beneficial conversion feature accounting models for convertible debt and convertible preferred stock. Additionally, ASU 2020-06 eliminates the treasury stock method to calculate diluted earnings per share for convertible instruments. ASU 2020-06 is effective for public business entities for fiscal years beginning after December 15, 2021 and interim periods within those fiscal years, or December 31, 2023 and interim periods within those fiscal years for companies who meet the SEC definition of smaller reporting company. Early adoption is permitted, and entities are allowed to adopt the guidance through either a modified retrospective method of transition or a fully retrospective method of transition. The Company early adopted this standard effective January 1, 2022 on a modified retrospective basis, and it did not have a material effect on the condensed consolidated financial statements and related disclosures. Pending Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses . This standard requires entities to measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. As a smaller reporting company, ASU 2016-13 will become effective for the Company for fiscal years beginning after December 15, 2022, and early adoption is permitted. The Company is currently evaluating the impact that ASU 2016-13 will have on its financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company has certain financial assets and liabilities that are recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements: • Level 1—quoted prices for identical instruments in active markets; • Level 2—quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets; and • Level 3—valuations derived from valuation techniques in which one or more significant value drivers are unobservable. The tables below present information about the Company’s financial assets and liabilities that are measured and carried at fair value as of March 31, 2022 and December 31, 2021 and indicate the level within the fair value hierarchy where each measurement is classified. The carrying amounts reflected in the condensed consolidated balance sheets for cash, prepaid expenses and other current assets, restricted cash, accounts payable and accrued expenses approximate their fair value due to their short-term nature. Level 1 Level 2 Level 3 Total March 31, 2022 Cash equivalents: Money market funds $ 44,940 $ — $ — $ 44,940 Investments, available for sale: U.S. Treasury obligations 49,643 — — 49,643 Marketable equity securities: Corporate equity securities 899 — — 899 Total $ 95,482 $ — $ — $ 95,482 Warrant liabilities (Note 13) $ — $ 16,594 $ — $ 16,594 Level 1 Level 2 Level 3 Total December 31, 2021 Cash equivalents: Money market funds $ 132,850 $ — $ — $ 132,850 Marketable equity securities: Corporate equity securities 1,463 — — 1,463 Total $ 134,313 $ — $ — $ 134,313 Warrant liabilities (Note 13) $ — $ 15,438 $ — $ 15,438

Cash, Cash Equivalents, Investm

Cash, Cash Equivalents, Investments and Marketable Equity Securities	3 Months Ended
	Mar. 31, 2022
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents, Investments and Marketable Equity Securities	Cash, Cash Equivalents, Investments and Marketable Equity Securities Cash equivalents include all highly liquid investments maturing within 90 days from the date of purchase. Investments consist of securities with original maturities greater than 90 days when purchased. The Company classifies these investments as available for sale and records them at fair value in the accompanying consolidated balance sheets. Unrealized gains or losses from equity securities are included in net income. Unrealized gains or losses from other investments, including debt securities, are included in accumulated other comprehensive (loss) income. Premiums or discounts from par value are amortized to investment income over the life of the underlying investment. Cash, cash equivalents, available-for-sale investments and marketable equity securities included the following as of March 31, 2022 and December 31, 2021: Average Maturity Amortized Cost Unrealized Gains Unrealized Losses Fair Value March 31, 2022 Cash $ 14,423 $ — $ — $ 14,423 Money market funds 44,940 — — 44,940 Total cash and cash equivalents $ 59,363 $ — $ — $ 59,363 U.S. Treasury obligations 87 days $ 49,685 $ — $ (42) $ 49,643 Total investments, available for sale $ 49,685 $ — $ (42) $ 49,643 March 31, 2022 Acquisition Value Unrealized Gains Unrealized Losses Fair Value Marketable equity securities $ 10,451 $ — $ (9,552) $ 899 Amortized Cost Unrealized Gains Unrealized Losses Fair Value December 31, 2021 Cash $ 8,786 $ — $ — $ 8,786 Money market funds 132,850 — — 132,850 Total cash and cash equivalents $ 141,636 $ — $ — $ 141,636 December 31, 2021 Acquisition Value Unrealized Gains Unrealized Losses Fair Value Marketable equity securities $ 10,451 $ — $ (8,988) $ 1,463

Restricted Cash

Restricted Cash	3 Months Ended
	Mar. 31, 2022
Cash and Cash Equivalents [Abstract]
Restricted Cash	Restricted Cash Restricted cash as of March 31, 2022 and 2021 was held as collateral for stand-by letters of credit issued by the Company to its landlord in connection with the current lease for its principal facilities located at 65 Hayden Avenue, Lexington, Massachusetts, or the Premises. For additional information regarding the Company’s lease, refer to Note 11. Cash, cash equivalents and restricted cash consisted of the following as of March 31, 2022 and 2021: March 31, March 31, Cash and cash equivalents $ 59,363 $ 89,772 Restricted cash 1,157 1,157 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 60,520 $ 90,929

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses and Other Liabilities	Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consisted of the following as of March 31, 2022 and December 31, 2021: March 31, December 31, Accrued professional fees and other $ 617 $ 1,094 Employee compensation and benefits 874 3,617 Research and development expenses 9,620 7,648 Accrued expenses and other liabilities $ 11,111 $ 12,359 Employee compensation and benefits, net of current portion $ — $ 28 Accrued expenses and other liabilities, net of current portion $ — $ 28

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Deferred tax assets and deferred tax liabilities are recognized based on temporary differences between the financial reporting and tax basis of assets and liabilities using statutory rates. A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized. The Company’s ability to use its operating loss carryforwards and tax credits to offset future taxable income is subject to restrictions under Sections 382 and 383 of the U.S. Internal Revenue Code, or the Code. Net operating loss and tax credit carryforwards may become subject to an annual limitation 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 under Sections 382 and 383 of the Internal Revenue Code. Such changes would limit the Company’s use of its operating loss carryforwards and tax credits. In such a situation, the Company may be required to pay income taxes, even though significant operating loss carryforwards and tax credits exist. The Company records a provision or benefit for income taxes on ordinary pre-tax income or loss based on its estimated effective tax rate for the year. As of March 31, 2022, the Company forecasts an ordinary pre-tax loss for the year ended December 31, 2022 and, since it maintains a full valuation allowance on its deferred tax assets, the Company did not record an income tax be nefit relating to this period. The Company adopted ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes , effective January 1, 2020. Under ASU 2019-12, the Company, having a full valuation and a loss in continuing operations, will no longer include the impacts of items in other comprehensive income in determining intra-period allocation of tax expense for continuing operations. Under ASU 2019-12, the Company can apply this change to intra-period tax allocation on a prospective basis. For the three months ended March 31, 2022, the Company applied the tax allocation rules of ASU 2019-12 to the $42 thousand of unrealized losses on available-for-sale investments recognized in other comprehensive loss, which did not have a material impact on the consolidated financial statements or related disclosures. Effective for tax years beginning on or after January 1, 2022, research and experimental expenditures under Section 174 of the Code must be capitalized over five years when performed in the United States and over 15 years when performed outside of the United States. The modification is an accounting method change that will require the filing of Form 3115 with the Company's 2022 tax return. As of March 31, 2022, the Company has performed a high-level analysis of the impact of this legislation and determined that the Company’s projected loss position for 2022 does not result in income tax. The Company maintains its full valuation allowance.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The Company’s revenue is generated through collaborative licensing agreements, patent assignments, intellectual property sales and asset sales. The Company generates its revenue through one segment. The revenue recognized under each of the Company’s arrangements during the current and prior periods is described below. Contract Assets The Company did not have a contract asset as of March 31, 2022 or December 31, 2021. Contract Liabilities As of March 31, 2022 and December 31, 2021, the Company had $2.8 million in contract liabilities related to unsatisfied performance obligations as well as variable consideration paid in advance, but currently constrained from recognition. Contract liabilities are presented as deferred revenue and classified as current or non-current based on the timing of when the Company expects to recognize revenue. The $2.8 million in contract liabilities consisted of deferred revenue related to a payment received from GlaxoSmithKline that the Company will not recognize as revenue until all repayment obligations lapse. Revenue Arrangements Vertex In July 2017, the Company completed the sale of worldwide development and commercialization rights to CTP-656, now known as VX-561, and other assets related to the treatment of cystic fibrosis to Vertex Pharmaceuticals, Inc., or Vertex. Pursuant to the Asset Purchase Agreement with Vertex, or the Vertex Agreement, the Company received $160.0 million in cash upon closing. Additionally, upon the achievement of certain milestone events, Vertex agreed to pay the Company an aggregate of up to $90.0 million, or the Milestone Obligation. In May 2021, the Company entered into an amendment to the Vertex Agreement, or the Vertex Amendment. Pursuant to the Vertex Amendment, Vertex paid the Company $32.0 million in cash in exchange for the removal of the Milestone Obligation. As a result of the Vertex Amendment, the Company is not entitled to receive any further payments pursuant to the Vertex Agreement. The Vertex Amendment changed the future obligations due from Vertex under the Vertex Agreement and was therefore treated as a contract modification. Since the Vertex Amendment does not provide for any new distinct goods and services and the single performance obligation related to the arrangement was previously satisfied, the Company recognized the $32.0 million payment from Vertex as Other Revenue during the year ended December 31, 2021. Previously, the variable consideration related to the Milestone Obligation was considered fully constrained due to the uncertainty associated with the achievement of the milestones. Pursuant to the Vertex Amendment, Vertex is no longer obligated to make these future milestone payments, and as a result, they are no longer considered variable consideration. There are no performance obligations or variable consideration remaining associated with the Vertex Agreement.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company’s equity incentive plans provide for the issuance of a variety of stock-based awards, including incentive stock options, nonstatutory stock options and awards of stock, to directors, officers and employees of the Company, as well as consultants and advisors to the Company. As of March 31, 2022, the Company has granted awards in the form of stock options and restricted stock units, or RSUs. The stock options generally have been granted with an exercise price equal to the closing market price of the Company’s common stock on the date of grant, a vesting period of one three Effective January 1, 2022, an additional 1,389,561 shares of common stock were added to the Company’s 2014 Stock Incentive Plan, or the 2014 Plan, for future issuance pursuant to the terms of the 2014 Plan. As of March 31, 2022, there were 2,026,725 shares of common stock available for future awards under the 2014 Plan. Total stock-based compensation expense related to all stock-based options and awards recognized in the condensed consolidated statements of operations and comprehensive loss consisted of: Three Months Ended March 31, 2022 2021 Research and development $ 950 $ 1,851 General and administrative 1,161 1,580 Total stock-based compensation expense $ 2,111 $ 3,431 Stock Options Stock options are valued using the Black-Scholes-Merton option valuation model, and compensation cost is recognized based on such fair value over the period of vesting. The weighted-average fair value of options granted in the three months ended March 31, 2022 and 2021 reflect the following weighted-average assumptions: Three Months Ended March 31, 2022 2021 Expected volatility 70.33% 69.71% Expected term 6.0 years 6.0 years Risk-free interest rate 2.33% 0.54% Expected dividend yield —% —% The following table provides certain information related to the Company’s outstanding stock options: Three Months Ended March 31, 2022 2021 (Amounts in thousands, except per share data) Weighted-average fair value of options granted, per option $ 2.47 $ 7.87 Aggregate grant date fair value of options vested during the period $ 1,909 $ 2,066 Total cash received from exercises of stock options $ — $ 89 Total intrinsic value of stock options exercised $ — $ 42 The following is a summary of stock option activity for the three months ended March 31, 2022: Number of Weighted Weighted Aggregate (in years) (in thousands) Outstanding at December 31, 2021 5,197,320 $ 14.21 Granted 29,200 $ 3.88 Exercised — $ — Forfeited or expired (178,506) $ 15.70 Outstanding at March 31, 2022 5,048,014 $ 14.09 5.8 $ 2 Exercisable at March 31, 2022 3,985,474 $ 14.72 5.2 $ 2 Vested and expected to vest at March 31, 2022 (1) 4,968,980 $ 14.13 5.8 $ 2 (1) Represents the number of vested stock option shares as of March 31, 2022, plus the number of unvested stock option shares that the Company estimated as of March 31, 2022 would vest, based on the unvested stock option shares as of March 31, 2022 and an estimated forfeiture rate of 7% . As of March 31, 2022, there w as $7.0 million of unre cognized compensation cost related to stock options that are expected to vest. The stock option costs are expected to be recognized over a weighted-average remaining vesting period of 2.1 years . Restricted Stock Units On February 14, 2020, or the 2020 RSU grant date, the Company granted 0.4 million RSUs, or the 2020 RSUs, to certain officers and employees. All of the 2020 RSUs are service-based and vest ratably over three years, with one third of the 2020 RSUs vesting on each anniversary of the 2020 RSU grant date through February 14, 2023. On January 5, 2021, or the January 2021 RSU grant date, the Company granted 0.3 million RSUs, or the January 2021 RSUs, to certain officers and employees. All of the January 2021 RSUs are service-based and vest ratably over three years, with one third of the January 2021 RSUs vesting on each anniversary of the January 2021 RSU grant date through January 5, 2024. On June 10, 2021, or the June 2021 RSU grant date, the Company granted 0.2 million RSUs, or the June 2021 RSUs, to directors and certain employees. All of the June 2021 RSUs are service-based, with half of the grants to employees vesting six months after the June 2021 RSU grant date and the remainder vesting on the first anniversary of the June 2021 RSU grant date, and the grants to directors vesting on the earlier of the first anniversary of the June 2021 RSU grant date or one day prior to the Company’s 2022 annual meeting of stockholders. On January 28, 2022, or the 2022 RSU grant date, the Company granted 0.7 million RSUs, or the 2022 RSUs, to certain officers and employees. All of the 2022 RSUs are service-based and vest ratably over three years, with one third of the 2022 RSUs vesting on each anniversary of the 2022 RSU grant date through January 28, 2025. Also on the 2022 RSU grant date, the Company granted 0.3 million performance-based RSUs, or the 2022 PSUs, to certain officers and employees. The 2022 PSUs vest as to the total number of shares granted one business day after the date on which the U.S. Food and Drug Administration, or FDA, notifies the Company that it has accepted for filing a New Drug Application, or NDA, for CTP-543, provided that the date of acceptance is on or before October 31, 2023. The Company is using the straight-line method to recognize expense over the requisite service period based on its estimate of the number of 2022 PSUs that will vest. If there is a change in the estimate of the number of 2022 PSUs that are probable of vesting, the Company will cumulatively adjust compensation expense in the period that the change in estimate is made. RSUs are not included in issued and outstanding common stock until the shares have vested and settled. As of March 31, 2022, 0.3 million of the 2020 RSUs, 0.1 million of the January 2021 RSUs and 0.1 million of the June 2021 RSUs had vested. T he fair value of an RSU is measured based on the market price of the underlying common stock on the date of grant. The following is a summary of RSU activity for the three months ended March 31, 2022: Number of Weighted- Outstanding at December 31, 2021 628,192 $ 10.78 Granted 1,005,575 $ 2.89 Released (214,315) $ 11.81 Forfeited (29,992) $ 9.40 Outstanding at March 31, 2022 1,389,460 $ 4.94 As of March 31, 2022, there was $5.2 million of u nrecognized compensation cost related to RSUs that are expected to vest. The RSU costs are expected to be recognized over a weighted-average remaining vesting pe riod of 2.1 years.

Loss Per Share

Loss Per Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Loss Per Share	Loss Per Share Basic net loss per common share is calculated by dividing net loss allocable to common stockholders by the weighted-average common shares outstanding during the period, without consideration of stock options, RSUs or preferred stock as common stock equivalents. The weighted-average common shares outstanding as of March 31, 2022 and 2021 includes pre-funded warrants to purchase up to an aggregate of 1.8 million shares of common stock that were issued in connection with a financing in 2020. For purposes of the diluted net loss per share calculation, common stock equivalents are excluded from the calculation if their effect would be anti-dilutive. As such, basic and diluted net loss per share applicable to common stockholders are the same for periods with a net loss. The following table illustrates the determination of loss per share for each period presented. Three Months Ended March 31, 2022 2021 (Amounts in thousands, except per share amounts) Numerator: Net loss applicable to common stockholders - basic and diluted $ (37,728) $ (22,669) Denominator: Weighted-average shares outstanding - basic and diluted 36,687 33,894 Net loss per share applicable to common stockholders - basic and diluted $ (1.03) $ (0.67) Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share: Stock options 5,048 5,366 Restricted stock units 1,389 822 Warrants 16,311 61 Series X1 Preferred Stock 13,997 —

Commitments

Commitments	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments	Commitments Lease The Company currently has a lease, or the Lease, for approximately 56,000 square feet of office and laboratory space located at the Premises. The Lease is classified as an operating lease. The lease term extends ten years following January 1, 2019. The Company is entitled to two five-year options to extend the Lease. The Lease provides for annual base rent of approximately $2.8 million in the first year following January 1, 2019, which increases on a yearly basis by 3.0% (subject to an abatement of base rent of approximately $0.5 million at the beginning of the second year of the lease term). There are no variable payments, exercise purchase options, penalties, fees or residual value guarantees under the Lease. The Company is also obligated to pay the landlord for certain costs, taxes and operating expenses related to the Premises, subject to certain exclusions. The Company recorded a liability for the Lease of $16.9 million on January 1, 2019. This lease liability is amortized over the remaining lease term in an amount equal to the difference between the cash rent paid and the monthly interest calculated on the remaining lease liability. As of March 31, 2022, the Company had a current lease liability of $1.2 million and a non-current lease liability of $13.6 million recorded in its condensed consolidated balance sheets. On January 1, 2019, the Company recorded a right-of-use asset in the amount of $9.5 million, which represents the lease liability of $16.9 million, adjusted for previously accrued rent of $2.9 million and previously recorded unamortized lease incentives in the amount of $4.5 million. The right-of-use asset is amortized over the remaining lease term in an amount equal to the difference between the calculated straight-line expense of the total lease payments less the monthly interest calculated on the remaining lease liability. As of March 31, 2022, the Company had a long-term lease asset of $8.5 million recorded in its condensed consolidated balance sheets. The Company recognizes lease expense, calculated as the remaining cost of the Lease allocated over the remaining lease term, on a straight-line basis. Lease expense is presented as part of continuing operations in the condensed consolidated statements of operations and comprehensive loss. For the three months ended March 31, 2022, the Company recogniz ed $0.6 million in lease expense. For the three months ended March 31, 2022, the Company paid $0.8 million in rent. As a payment arising from an operating lease, the $0.8 million is classified within operating activities in the condensed consolidated statements of cash flows. For the three months ended March 31, 2022 and 2021, the weighted-average remaining lease term was 6.75 years and 7.75 years, respectively, and the weighted-average discount rate was 13.08%.

Open Market Sale Agreement

Open Market Sale Agreement	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Open Market Sale Agreement	Open Market Sale Agreement On March 1, 2019, the Company entered into an Open Market Sale Agreement, or the ATM Agreement, with Jefferies LLC, or Jefferies, with respect to an at-the-market offering program under which the Company may sell, from time to time at its sole discretion, shares of common stock having an aggregate offering price of up to $50.0 million, referred to as Placement Shares, through Jefferies as its sales agent. The Company will pay Jefferies a commission equal to 3.0% of the gross sales proceeds of any Placement Shares sold through Jefferies under the ATM Agreement. On November 5, 2020, the Company entered into an amendment to the ATM Agreement with Jefferies to increase the aggregate offering price of Placement Shares that may be sold pursuant to the ATM Agreement from up to $50.0 million to up to $100.0 million. However, on March 7, 2021, the Company’s ability to further use the first $50.0 million expired. As a result, after March 7, 2021, the Company may only sell up to an additional $50.0 million pursuant to the ATM Agreement. During the year ended December 31, 2021, the Company sold 165,323 shares of common stock pursuant to the ATM Agreement for net proceeds of $2.0 million, after payment of cash commissions of 3.0% of the gross proceeds to Jefferies. Cash provided by financing activities for the three months ended March 31, 2021 includes $0.5 million in net proceeds from sales pursuant to the ATM Agreement that had been classified as a receivable as of December 31, 2020. During the three months ended March 31, 2022, the Company did not sell any shares of common stock pursuant to the ATM Agreement. In November 2021, the Company entered into a structured financing, or the 2021 Financing, consisting of a securities purchase agreement, warrant agreements, or the Warrants, and a royalty purchase agreement, or the RPA. Pursuant to the 2021 Financing, the Company received aggregate gross proceeds of $65.0 million in exchange for the sale to a select group of institutional investors, or the Investors, of (i) 2,253,000 shares of common stock, (ii) 13,997 shares of Series X1 Preferred Stock, (iii) Warrants to purchase up to 16,250 shares of Series X1 Preferred Stock and (iv) a portion of the Company’s right to receive potential future AVP-786 royalties, or the Royalty Interest, under an existing development and licensing agreement, or the Avanir Agreement, with Avanir Pharmaceuticals, Inc., or Avanir, a subsidiary of Otsuka Pharmaceuticals, Co., Ltd. Preferred Stock In November 2021, the Company filed a certificate of designation with the Delaware Secretary of State setting forth the preferences, rights and limitations of a newly designated series of preferred stock known as “Series X1 Preferred Stock.” 32,500 shares have been designated as Series X1 Preferred Stock. The Series X1 Preferred Stock is convertible into shares of common stock at a conversion rate of 1,000 shares of common stock per share of Series X1 Preferred Stock, at the option of the holder, subject to certain limitations. Except in limited circumstances, the Series X1 Preferred Stock does not have voting rights. Holders of the Series X1 Preferred Stock are entitled to receive dividends on an as converted to common stock basis when and if declared. In any liquidation or dissolution of the Company, the Series X1 Preferred Stock will rank on parity with the common stock in the distribution of assets, to the extent legally available for distribution, and will receive any dividends declared but unpaid on such shares. Warrants The Warrants consisted of (i) warrants to purchase an aggregate of 8,125 shares of Series X1 Preferred Stock at an initial exercise price (on a common stock equivalent basis) of $5.34 per share, or the First Tranche Warrants, and (ii) warrants to purchase an aggregate of an additional 8,125 shares of Series X1 Preferred Stock at an initial exercise price (on a common stock equivalent basis) of $7.35 per share, or the Second Tranche Warrants. The Warrants are exercisable at any time prior to the expiration date. The term of the First Tranche Warrants and Second Tranche Warrants is contingent on the outcome of the Company’s CTP-543 THRIVE-AA1 Phase 3 clinical trial and THRIVE-AA2 Phase 3 clinical trial, respectively. The Warrants expire 90 days after the occurrence of both (i) the public disclosure by the Company of the achievement of statistical significance on each of the primary endpoints of the respective clinical trial and (ii) a determination by the Company that there are no safety or other issues that would impede the Company’s filing of an NDA without first requiring an additional clinical trial that is not already contemplated by the Company’s development plans for CTP-543. In the event that either event (i) or (ii) does not occur, the Warrants will expire 90 days after the earlier of (a) the public release of topline data from two ongoing Phase 3 clinical trials being conducted by Avanir in the indication of agitation in Alzheimer’s disease patients and (b) written notification to the Investors that the Company has received written notice from Avanir of a decision to cease both such clinical trials early. In the event that neither event (a) nor (b) occurs, the Warrants will expire upon the tenth anniversary from issuance. The exercise price of the Warrants is subject to a one-time adjustment in the event that the Company sells capital stock or derivative securities convertible into or exercisable for capital stock (subject to certain exemptions) at a weighted-average price per share below the initial exercise price, in which case the initial exercise price will be automatically reset upon exercise of the Warrant to an exercise price that is the midpoint between the initial exercise price and the weighted-average price per share, provided that the adjusted exercise price cannot be less than $2.88 per share. Royalty Interest As part of the 2021 Financing, under the RPA, the Investors purchased the Royalty Interest. Investors are initially entitled to an aggregate base amount of the future royalty payments of 35.0% in respect of worldwide net sales of licensed products under the Avanir Agreement, and may increase their percentage ownership (i) by up to 7.5% upon the exercise in full by the Investors of the First Tranche Warrants and (ii) by up to an additional 7.5% upon the exercise in full by the Investors of the Second Tranche Warrants. Upon exercise of any portion of the First Tranche Warrants and/or Second Tranche Warrants by any Investor, such Investor is entitled to receive its pro rata share of the percentages set forth in the RPA. Accounting Treatment The Company received aggregate net proceeds of $64.4 million from the 2021 Financing after deducting offering expenses of $0.6 million payable by the Company. The common stock, Series X1 Preferred Stock, Warrants and Royalty Interest were determined to be freestanding instruments, as they are legally detachable and separately exercisable from each other. The Series X1 Preferred Stock is not redeemable outside the control of the Company, and the Company has the ability to settle any conversion in shares. As such, the Series X1 Preferred Stock is classified as a component of permanent stockholders’ equity within additional paid-in capital. The ability of the Series X1 Preferred Stock to be converted to common stock, or the Conversion Option, represents an embedded call option, and therefore, the Company performed an evaluation in accordance with ASC 815, Derivatives and Hedging , to determine whether the Conversion Option requires bifurcation as a derivative. As a result of the evaluation, the Company concluded that the Conversion Option feature is clearly and closely related to the equity host instrument and is not an embedded derivative requiring bifurcation. Additionally, the Company evaluated the Series X1 Preferred Stock for a beneficial conversion feature in accordance with ASC 470, Debt . The evaluation identified a beneficial conversion feature; however, because the Series X1 Preferred Stock was recorded at par value with the incremental amount recorded to additional paid-in capital, the beneficial conversion feature had no impact. As of January 1, 2022, the Company adopted ASU 2020-06. ASU 2020-06 eliminates the cash conversion and beneficial conversion feature accounting models for convertible debt and convertible preferred stock. As a result, the Company's adoption of ASU 2020-06 eliminated the beneficial conversion feature of the Series X1 Preferred Stock. The Warrants include an exercise contingency that is based on an observable index other than the Company’s own operations, and therefore, are precluded from equity classification. As a result, the Warrants are classified as a liability and measured at fair value at inception with subsequent changes in fair value recognized in earnings as further discussed below. The Royalty Interest does not meet the debt classification criteria, and as such, is accounted for under the deferred income model to be amortized under the units of revenue method. The two options to acquire an additional 7.5% of ownership in future AVP-786 royalties, or the Royalty Step Ups, are features embedded in the Royalty Interest. The Royalty Step Ups do not require bifurcation, as they are subject to scope exception because they pertain to the sale of future revenues. The aggregate proceeds of the 2021 Financing were first allocated to the Warrants based on fair value, with the remaining proceeds allocated to the common stock, Series X1 Preferred Stock and Royalty Interest on a relative fair value basis. The First Tranche Warrants and Second Tranche Warrants were valued using a Black-Scholes-Merton option pricing model, resulting in a fair value of $7.5 million and $5.9 million, respectively, as of the date the Company entered into the 2021 Financing. The relative fair value allocated to common stock and Series X1 Preferred Stock totaled $6.5 million and $40.3 million, respectively. The relative fair value allocated to the Royalty Interest was $4.8 million. Warrant Fair Value Assumptions As of March 31, 2022 and December 31, 2021, the fair value of the First Tranche Warrants was $8.8 million and $8.5 million, respectively, and Second Tranche Warrants was $7.8 million and $6.9 million, respectively. The Company estimated the fair value of the Warrants using the Black-Scholes-Merton option pricing model. The fair value assumptions related to the Warrants as of March 31, 2022 and December 31, 2021 were as follows: As of March 31, 2022 Tranche 1 Warrants Tranche 2 Warrants Expected volatility 74.42% 78.21% Expected term 2.38 years 2.55 years Risk-free interest rate 2.37% 2.37% Expected dividend yield —% —% As of December 31, 2021 Tranche 1 Warrants Tranche 2 Warrants Expected volatility 75.90% 76.40% Expected term 2.68 years 2.80 years Risk-free interest rate 0.97% 0.97% Expected dividend yield —% —% The expected term is probability-weighted based on the anticipated terms dictated by the possible outcomes of the Warrants. The expected volatility is calculated based on the historical volatility of the Company commensurate with the expected term. The risk-free interest rate is based on the average treasury bill interest rate over a period commensurate with the expected term. The expected dividend yield is zero, as the Company has not paid any dividends to date and has no current intention of paying cash dividends. Related Party Participation in the 2021 Financing The Investors included RA Capital Healthcare Fund, L.P., or RA Capital. At the time of entering into the 2021 Financing, RA Capital held greater than 5% of the Company's outstanding common stock, and two members of the Company's board of directors maintained minority, non-controlling interests in RA Capital. RA Capital purchased 7,500 shares of Series X1 Preferred Stock, 7,500 Warrants and a base amount of 16.2%, which could potentially increase up to 23.1%, of the Royalty Interest for $30.0 million in cash. As of March 31, 2022 and December 31, 2021, the Company's condensed consolidated balance sheet includes RA Capital's portion of warrant liabilities of $7.7 million and $7.1 million, respectively, and deferred revenue of $2.2 million for both periods. For the three months ended March 31, 2022, the Company's condensed consolidated statement of operations and condensed consolidated statement of cash flows include RA Capital's portion of the unrealized loss on warrant liabilities of $0.5 million.

2021 Sale of Common and Preferr

2021 Sale of Common and Preferred Stock, Warrants and Royalty Interest	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
2021 Sale of Common and Preferred Stock, Warrants and Royalty Interest	Open Market Sale Agreement On March 1, 2019, the Company entered into an Open Market Sale Agreement, or the ATM Agreement, with Jefferies LLC, or Jefferies, with respect to an at-the-market offering program under which the Company may sell, from time to time at its sole discretion, shares of common stock having an aggregate offering price of up to $50.0 million, referred to as Placement Shares, through Jefferies as its sales agent. The Company will pay Jefferies a commission equal to 3.0% of the gross sales proceeds of any Placement Shares sold through Jefferies under the ATM Agreement. On November 5, 2020, the Company entered into an amendment to the ATM Agreement with Jefferies to increase the aggregate offering price of Placement Shares that may be sold pursuant to the ATM Agreement from up to $50.0 million to up to $100.0 million. However, on March 7, 2021, the Company’s ability to further use the first $50.0 million expired. As a result, after March 7, 2021, the Company may only sell up to an additional $50.0 million pursuant to the ATM Agreement. During the year ended December 31, 2021, the Company sold 165,323 shares of common stock pursuant to the ATM Agreement for net proceeds of $2.0 million, after payment of cash commissions of 3.0% of the gross proceeds to Jefferies. Cash provided by financing activities for the three months ended March 31, 2021 includes $0.5 million in net proceeds from sales pursuant to the ATM Agreement that had been classified as a receivable as of December 31, 2020. During the three months ended March 31, 2022, the Company did not sell any shares of common stock pursuant to the ATM Agreement. In November 2021, the Company entered into a structured financing, or the 2021 Financing, consisting of a securities purchase agreement, warrant agreements, or the Warrants, and a royalty purchase agreement, or the RPA. Pursuant to the 2021 Financing, the Company received aggregate gross proceeds of $65.0 million in exchange for the sale to a select group of institutional investors, or the Investors, of (i) 2,253,000 shares of common stock, (ii) 13,997 shares of Series X1 Preferred Stock, (iii) Warrants to purchase up to 16,250 shares of Series X1 Preferred Stock and (iv) a portion of the Company’s right to receive potential future AVP-786 royalties, or the Royalty Interest, under an existing development and licensing agreement, or the Avanir Agreement, with Avanir Pharmaceuticals, Inc., or Avanir, a subsidiary of Otsuka Pharmaceuticals, Co., Ltd. Preferred Stock In November 2021, the Company filed a certificate of designation with the Delaware Secretary of State setting forth the preferences, rights and limitations of a newly designated series of preferred stock known as “Series X1 Preferred Stock.” 32,500 shares have been designated as Series X1 Preferred Stock. The Series X1 Preferred Stock is convertible into shares of common stock at a conversion rate of 1,000 shares of common stock per share of Series X1 Preferred Stock, at the option of the holder, subject to certain limitations. Except in limited circumstances, the Series X1 Preferred Stock does not have voting rights. Holders of the Series X1 Preferred Stock are entitled to receive dividends on an as converted to common stock basis when and if declared. In any liquidation or dissolution of the Company, the Series X1 Preferred Stock will rank on parity with the common stock in the distribution of assets, to the extent legally available for distribution, and will receive any dividends declared but unpaid on such shares. Warrants The Warrants consisted of (i) warrants to purchase an aggregate of 8,125 shares of Series X1 Preferred Stock at an initial exercise price (on a common stock equivalent basis) of $5.34 per share, or the First Tranche Warrants, and (ii) warrants to purchase an aggregate of an additional 8,125 shares of Series X1 Preferred Stock at an initial exercise price (on a common stock equivalent basis) of $7.35 per share, or the Second Tranche Warrants. The Warrants are exercisable at any time prior to the expiration date. The term of the First Tranche Warrants and Second Tranche Warrants is contingent on the outcome of the Company’s CTP-543 THRIVE-AA1 Phase 3 clinical trial and THRIVE-AA2 Phase 3 clinical trial, respectively. The Warrants expire 90 days after the occurrence of both (i) the public disclosure by the Company of the achievement of statistical significance on each of the primary endpoints of the respective clinical trial and (ii) a determination by the Company that there are no safety or other issues that would impede the Company’s filing of an NDA without first requiring an additional clinical trial that is not already contemplated by the Company’s development plans for CTP-543. In the event that either event (i) or (ii) does not occur, the Warrants will expire 90 days after the earlier of (a) the public release of topline data from two ongoing Phase 3 clinical trials being conducted by Avanir in the indication of agitation in Alzheimer’s disease patients and (b) written notification to the Investors that the Company has received written notice from Avanir of a decision to cease both such clinical trials early. In the event that neither event (a) nor (b) occurs, the Warrants will expire upon the tenth anniversary from issuance. The exercise price of the Warrants is subject to a one-time adjustment in the event that the Company sells capital stock or derivative securities convertible into or exercisable for capital stock (subject to certain exemptions) at a weighted-average price per share below the initial exercise price, in which case the initial exercise price will be automatically reset upon exercise of the Warrant to an exercise price that is the midpoint between the initial exercise price and the weighted-average price per share, provided that the adjusted exercise price cannot be less than $2.88 per share. Royalty Interest As part of the 2021 Financing, under the RPA, the Investors purchased the Royalty Interest. Investors are initially entitled to an aggregate base amount of the future royalty payments of 35.0% in respect of worldwide net sales of licensed products under the Avanir Agreement, and may increase their percentage ownership (i) by up to 7.5% upon the exercise in full by the Investors of the First Tranche Warrants and (ii) by up to an additional 7.5% upon the exercise in full by the Investors of the Second Tranche Warrants. Upon exercise of any portion of the First Tranche Warrants and/or Second Tranche Warrants by any Investor, such Investor is entitled to receive its pro rata share of the percentages set forth in the RPA. Accounting Treatment The Company received aggregate net proceeds of $64.4 million from the 2021 Financing after deducting offering expenses of $0.6 million payable by the Company. The common stock, Series X1 Preferred Stock, Warrants and Royalty Interest were determined to be freestanding instruments, as they are legally detachable and separately exercisable from each other. The Series X1 Preferred Stock is not redeemable outside the control of the Company, and the Company has the ability to settle any conversion in shares. As such, the Series X1 Preferred Stock is classified as a component of permanent stockholders’ equity within additional paid-in capital. The ability of the Series X1 Preferred Stock to be converted to common stock, or the Conversion Option, represents an embedded call option, and therefore, the Company performed an evaluation in accordance with ASC 815, Derivatives and Hedging , to determine whether the Conversion Option requires bifurcation as a derivative. As a result of the evaluation, the Company concluded that the Conversion Option feature is clearly and closely related to the equity host instrument and is not an embedded derivative requiring bifurcation. Additionally, the Company evaluated the Series X1 Preferred Stock for a beneficial conversion feature in accordance with ASC 470, Debt . The evaluation identified a beneficial conversion feature; however, because the Series X1 Preferred Stock was recorded at par value with the incremental amount recorded to additional paid-in capital, the beneficial conversion feature had no impact. As of January 1, 2022, the Company adopted ASU 2020-06. ASU 2020-06 eliminates the cash conversion and beneficial conversion feature accounting models for convertible debt and convertible preferred stock. As a result, the Company's adoption of ASU 2020-06 eliminated the beneficial conversion feature of the Series X1 Preferred Stock. The Warrants include an exercise contingency that is based on an observable index other than the Company’s own operations, and therefore, are precluded from equity classification. As a result, the Warrants are classified as a liability and measured at fair value at inception with subsequent changes in fair value recognized in earnings as further discussed below. The Royalty Interest does not meet the debt classification criteria, and as such, is accounted for under the deferred income model to be amortized under the units of revenue method. The two options to acquire an additional 7.5% of ownership in future AVP-786 royalties, or the Royalty Step Ups, are features embedded in the Royalty Interest. The Royalty Step Ups do not require bifurcation, as they are subject to scope exception because they pertain to the sale of future revenues. The aggregate proceeds of the 2021 Financing were first allocated to the Warrants based on fair value, with the remaining proceeds allocated to the common stock, Series X1 Preferred Stock and Royalty Interest on a relative fair value basis. The First Tranche Warrants and Second Tranche Warrants were valued using a Black-Scholes-Merton option pricing model, resulting in a fair value of $7.5 million and $5.9 million, respectively, as of the date the Company entered into the 2021 Financing. The relative fair value allocated to common stock and Series X1 Preferred Stock totaled $6.5 million and $40.3 million, respectively. The relative fair value allocated to the Royalty Interest was $4.8 million. Warrant Fair Value Assumptions As of March 31, 2022 and December 31, 2021, the fair value of the First Tranche Warrants was $8.8 million and $8.5 million, respectively, and Second Tranche Warrants was $7.8 million and $6.9 million, respectively. The Company estimated the fair value of the Warrants using the Black-Scholes-Merton option pricing model. The fair value assumptions related to the Warrants as of March 31, 2022 and December 31, 2021 were as follows: As of March 31, 2022 Tranche 1 Warrants Tranche 2 Warrants Expected volatility 74.42% 78.21% Expected term 2.38 years 2.55 years Risk-free interest rate 2.37% 2.37% Expected dividend yield —% —% As of December 31, 2021 Tranche 1 Warrants Tranche 2 Warrants Expected volatility 75.90% 76.40% Expected term 2.68 years 2.80 years Risk-free interest rate 0.97% 0.97% Expected dividend yield —% —% The expected term is probability-weighted based on the anticipated terms dictated by the possible outcomes of the Warrants. The expected volatility is calculated based on the historical volatility of the Company commensurate with the expected term. The risk-free interest rate is based on the average treasury bill interest rate over a period commensurate with the expected term. The expected dividend yield is zero, as the Company has not paid any dividends to date and has no current intention of paying cash dividends. Related Party Participation in the 2021 Financing The Investors included RA Capital Healthcare Fund, L.P., or RA Capital. At the time of entering into the 2021 Financing, RA Capital held greater than 5% of the Company's outstanding common stock, and two members of the Company's board of directors maintained minority, non-controlling interests in RA Capital. RA Capital purchased 7,500 shares of Series X1 Preferred Stock, 7,500 Warrants and a base amount of 16.2%, which could potentially increase up to 23.1%, of the Royalty Interest for $30.0 million in cash. As of March 31, 2022 and December 31, 2021, the Company's condensed consolidated balance sheet includes RA Capital's portion of warrant liabilities of $7.7 million and $7.1 million, respectively, and deferred revenue of $2.2 million for both periods. For the three months ended March 31, 2022, the Company's condensed consolidated statement of operations and condensed consolidated statement of cash flows include RA Capital's portion of the unrealized loss on warrant liabilities of $0.5 million.

Basis of Presentation Significa

Basis of Presentation Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments, consisting of normal recurring accruals and revisions of estimates, considered necessary for a fair presentation of the condensed consolidated financial statements have been included. Interim results for the three months ended March 31, 2022 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2022 or any other future period. The accompanying condensed consolidated financial statements reflect the accounts of the Company and its subsidiaries. All intercompany transactions between the Company and its subsidiaries have been eliminated. Management has determined that the Company operates in one segment: the development of pharmaceutical products on its own behalf or in collaboration with others. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and the accompanying notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021 filed with the Securities and Exchange Commission, or SEC, on March 3, 2022. Unless otherwise indicated, all amounts in the following tables are in thousands except share and per share amounts.
Use of Estimates and Summary of Significant Accounting Policies	Use of Estimates and Summary of Significant Accounting Policies The preparation of the consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenue, expenses and the disclosure of contingent assets and liabilities and the Company’s ability to continue as a going concern. In preparing the consolidated financial statements, management used estimates in the following areas, among others: revenue recognition; prepaid and accrued research and development expenses; stock-based compensation expense; fair value of warrant liabilities; and the evaluation of the existence of conditions and events that raise substantial doubt regarding the Company’s ability to continue as a going concern. Actual results could differ from those estimates. During the three months ended March 31, 2022, there have been no material changes to the significant accounting policies previously disclosed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In August 2020, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity . ASU 2020-06 simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts in an entity’s own stock, by eliminating the cash conversion and beneficial conversion feature accounting models for convertible debt and convertible preferred stock. Additionally, ASU 2020-06 eliminates the treasury stock method to calculate diluted earnings per share for convertible instruments. ASU 2020-06 is effective for public business entities for fiscal years beginning after December 15, 2021 and interim periods within those fiscal years, or December 31, 2023 and interim periods within those fiscal years for companies who meet the SEC definition of smaller reporting company. Early adoption is permitted, and entities are allowed to adopt the guidance through either a modified retrospective method of transition or a fully retrospective method of transition. The Company early adopted this standard effective January 1, 2022 on a modified retrospective basis, and it did not have a material effect on the condensed consolidated financial statements and related disclosures. Pending Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses . This standard requires entities to measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. As a smaller reporting company, ASU 2016-13 will become effective for the Company for fiscal years beginning after December 15, 2022, and early adoption is permitted. The Company is currently evaluating the impact that ASU 2016-13 will have on its financial statements and related disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities recognized at fair value	The tables below present information about the Company’s financial assets and liabilities that are measured and carried at fair value as of March 31, 2022 and December 31, 2021 and indicate the level within the fair value hierarchy where each measurement is classified. The carrying amounts reflected in the condensed consolidated balance sheets for cash, prepaid expenses and other current assets, restricted cash, accounts payable and accrued expenses approximate their fair value due to their short-term nature. Level 1 Level 2 Level 3 Total March 31, 2022 Cash equivalents: Money market funds $ 44,940 $ — $ — $ 44,940 Investments, available for sale: U.S. Treasury obligations 49,643 — — 49,643 Marketable equity securities: Corporate equity securities 899 — — 899 Total $ 95,482 $ — $ — $ 95,482 Warrant liabilities (Note 13) $ — $ 16,594 $ — $ 16,594 Level 1 Level 2 Level 3 Total December 31, 2021 Cash equivalents: Money market funds $ 132,850 $ — $ — $ 132,850 Marketable equity securities: Corporate equity securities 1,463 — — 1,463 Total $ 134,313 $ — $ — $ 134,313 Warrant liabilities (Note 13) $ — $ 15,438 $ — $ 15,438

Cash, Cash Equivalents, Inves_2

Cash, Cash Equivalents, Investments and Marketable Equity Securities (Tables)	3 Months Ended
	Mar. 31, 2022
Cash and Cash Equivalents [Abstract]
Schedule of cash, cash equivalents and investments, available for sale	Cash, cash equivalents, available-for-sale investments and marketable equity securities included the following as of March 31, 2022 and December 31, 2021: Average Maturity Amortized Cost Unrealized Gains Unrealized Losses Fair Value March 31, 2022 Cash $ 14,423 $ — $ — $ 14,423 Money market funds 44,940 — — 44,940 Total cash and cash equivalents $ 59,363 $ — $ — $ 59,363 U.S. Treasury obligations 87 days $ 49,685 $ — $ (42) $ 49,643 Total investments, available for sale $ 49,685 $ — $ (42) $ 49,643 March 31, 2022 Acquisition Value Unrealized Gains Unrealized Losses Fair Value Marketable equity securities $ 10,451 $ — $ (9,552) $ 899 Amortized Cost Unrealized Gains Unrealized Losses Fair Value December 31, 2021 Cash $ 8,786 $ — $ — $ 8,786 Money market funds 132,850 — — 132,850 Total cash and cash equivalents $ 141,636 $ — $ — $ 141,636 December 31, 2021 Acquisition Value Unrealized Gains Unrealized Losses Fair Value Marketable equity securities $ 10,451 $ — $ (8,988) $ 1,463

Restricted Cash (Tables)

Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2022
Cash and Cash Equivalents [Abstract]
Schedule of cash, cash equivalents and restricted cash	Cash, cash equivalents and restricted cash consisted of the following as of March 31, 2022 and 2021: March 31, March 31, Cash and cash equivalents $ 59,363 $ 89,772 Restricted cash 1,157 1,157 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 60,520 $ 90,929

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Schedule of accrued expenses and other liabilities	Accrued expenses and other liabilities consisted of the following as of March 31, 2022 and December 31, 2021: March 31, December 31, Accrued professional fees and other $ 617 $ 1,094 Employee compensation and benefits 874 3,617 Research and development expenses 9,620 7,648 Accrued expenses and other liabilities $ 11,111 $ 12,359 Employee compensation and benefits, net of current portion $ — $ 28 Accrued expenses and other liabilities, net of current portion $ — $ 28

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Schedule of stock-based compensation expense related to all stock based awards recognized in statements of operations and comprehensive loss	Total stock-based compensation expense related to all stock-based options and awards recognized in the condensed consolidated statements of operations and comprehensive loss consisted of: Three Months Ended March 31, 2022 2021 Research and development $ 950 $ 1,851 General and administrative 1,161 1,580 Total stock-based compensation expense $ 2,111 $ 3,431
Summary of estimated weighted-average assumptions of options granted	The weighted-average fair value of options granted in the three months ended March 31, 2022 and 2021 reflect the following weighted-average assumptions: Three Months Ended March 31, 2022 2021 Expected volatility 70.33% 69.71% Expected term 6.0 years 6.0 years Risk-free interest rate 2.33% 0.54% Expected dividend yield —% —% As of March 31, 2022 Tranche 1 Warrants Tranche 2 Warrants Expected volatility 74.42% 78.21% Expected term 2.38 years 2.55 years Risk-free interest rate 2.37% 2.37% Expected dividend yield —% —% As of December 31, 2021 Tranche 1 Warrants Tranche 2 Warrants Expected volatility 75.90% 76.40% Expected term 2.68 years 2.80 years Risk-free interest rate 0.97% 0.97% Expected dividend yield —% —%
Schedule of outstanding stock options	The following table provides certain information related to the Company’s outstanding stock options: Three Months Ended March 31, 2022 2021 (Amounts in thousands, except per share data) Weighted-average fair value of options granted, per option $ 2.47 $ 7.87 Aggregate grant date fair value of options vested during the period $ 1,909 $ 2,066 Total cash received from exercises of stock options $ — $ 89 Total intrinsic value of stock options exercised $ — $ 42
Summary of stock option activity	The following is a summary of stock option activity for the three months ended March 31, 2022: Number of Weighted Weighted Aggregate (in years) (in thousands) Outstanding at December 31, 2021 5,197,320 $ 14.21 Granted 29,200 $ 3.88 Exercised — $ — Forfeited or expired (178,506) $ 15.70 Outstanding at March 31, 2022 5,048,014 $ 14.09 5.8 $ 2 Exercisable at March 31, 2022 3,985,474 $ 14.72 5.2 $ 2 Vested and expected to vest at March 31, 2022 (1) 4,968,980 $ 14.13 5.8 $ 2 (1) Represents the number of vested stock option shares as of March 31, 2022, plus the number of unvested stock option shares that the Company estimated as of March 31, 2022 would vest, based on the unvested stock option shares as of March 31, 2022 and an estimated forfeiture rate of 7% .
Summary of RSU activity	The following is a summary of RSU activity for the three months ended March 31, 2022: Number of Weighted- Outstanding at December 31, 2021 628,192 $ 10.78 Granted 1,005,575 $ 2.89 Released (214,315) $ 11.81 Forfeited (29,992) $ 9.40 Outstanding at March 31, 2022 1,389,460 $ 4.94

Loss Per Share (Tables)

Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Schedule of loss per share, basic and diluted	The following table illustrates the determination of loss per share for each period presented. Three Months Ended March 31, 2022 2021 (Amounts in thousands, except per share amounts) Numerator: Net loss applicable to common stockholders - basic and diluted $ (37,728) $ (22,669) Denominator: Weighted-average shares outstanding - basic and diluted 36,687 33,894 Net loss per share applicable to common stockholders - basic and diluted $ (1.03) $ (0.67) Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share: Stock options 5,048 5,366 Restricted stock units 1,389 822 Warrants 16,311 61 Series X1 Preferred Stock 13,997 —

2021 Sale of Common and Prefe_2

2021 Sale of Common and Preferred Stock, Warrants and Royalty Interest (Tables)	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Summary of estimated weighted-average assumptions of options granted	The weighted-average fair value of options granted in the three months ended March 31, 2022 and 2021 reflect the following weighted-average assumptions: Three Months Ended March 31, 2022 2021 Expected volatility 70.33% 69.71% Expected term 6.0 years 6.0 years Risk-free interest rate 2.33% 0.54% Expected dividend yield —% —% As of March 31, 2022 Tranche 1 Warrants Tranche 2 Warrants Expected volatility 74.42% 78.21% Expected term 2.38 years 2.55 years Risk-free interest rate 2.37% 2.37% Expected dividend yield —% —% As of December 31, 2021 Tranche 1 Warrants Tranche 2 Warrants Expected volatility 75.90% 76.40% Expected term 2.68 years 2.80 years Risk-free interest rate 0.97% 0.97% Expected dividend yield —% —%

Nature of Business - Additional

Nature of Business - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash equivalents and investments	$ 109,000
Net working capital	99,700
Accumulated deficit	$ (387,226)	$ (349,498)

Basis of Presentation Signifi_2

Basis of Presentation Significant Accounting Policies - Additional Information (Details)	3 Months Ended
	Mar. 31, 2022segment
Accounting Policies [Abstract]
Number of segments	1

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Recognized at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, cash equivalents	$ 59,363	$ 141,636
Warrant liabilities, long-term	16,594	15,438
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, cash equivalents	44,940	132,850
Fair value measurements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Corporate equity securities	899	1,463
Total financial assets at fair value	95,482	134,313
Warrant liabilities, long-term	16,594	15,438
Fair value measurements | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Corporate equity securities	899	1,463
Total financial assets at fair value	95,482	134,313
Warrant liabilities, long-term	0	0
Fair value measurements | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Corporate equity securities	0	0
Total financial assets at fair value	0	0
Warrant liabilities, long-term	16,594	15,438
Fair value measurements | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Corporate equity securities	0	0
Total financial assets at fair value	0	0
Warrant liabilities, long-term	0	0
Fair value measurements | U.S. Treasury obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, investments available-for-sale securities	49,643
Fair value measurements | U.S. Treasury obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, investments available-for-sale securities	49,643
Fair value measurements | U.S. Treasury obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, investments available-for-sale securities	0
Fair value measurements | U.S. Treasury obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, investments available-for-sale securities	0
Fair value measurements | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, cash equivalents	44,940	132,850
Fair value measurements | Money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, cash equivalents	44,940	132,850
Fair value measurements | Money market funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, cash equivalents	0	0
Fair value measurements | Money market funds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value, cash equivalents	$ 0	$ 0

Cash, Cash Equivalents, Inves_3

Cash, Cash Equivalents, Investments and Marketable Equity Securities - Cash, Cash Equivalents, Available for Sale Investments and Marketable Equity Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Cash and Cash Equivalents
Amortized cost, cash and cash equivalents	$ 59,363	$ 141,636	$ 89,772
Fair value, cash and cash equivalent	59,363	141,636
Total investments, available for sale
Cash and Cash Equivalents
Amortized Cost	49,685
Unrealized Losses	(42)
Fair value, investments available-for-sale securities	49,643
U.S. Treasury obligations
Cash and Cash Equivalents
Amortized Cost	49,685
Unrealized Losses	(42)
Fair value, investments available-for-sale securities	$ 49,643
U.S. Treasury obligations | Expected term (in years)
Marketable Securities
Average Maturity	87 days
Marketable equity securities
Marketable Securities
Acquisition Value	$ 10,451	10,451
Unrealized Gains	0	0
Unrealized Losses	(9,552)	(8,988)
Fair Value	899	1,463
Cash
Cash and Cash Equivalents
Amortized cost, cash and cash equivalents	14,423	8,786
Fair value, cash and cash equivalent	14,423	8,786
Money market funds
Cash and Cash Equivalents
Amortized cost, cash and cash equivalents	44,940	132,850
Fair value, cash and cash equivalent	$ 44,940	$ 132,850

Restricted Cash (Details)

Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 59,363	$ 141,636	$ 89,772
Restricted cash	1,157	1,157	1,157
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	$ 60,520	$ 142,793	$ 90,929	$ 78,359

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued professional fees and other	$ 617	$ 1,094
Employee compensation and benefits	874	3,617
Research and development expenses	9,620	7,648
Accrued expenses and other liabilities	11,111	12,359
Employee compensation and benefits, net of current portion	0	28
Accrued expenses and other liabilities, net of current portion	$ 0	$ 28

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Unrealized loss on short-term investments	$ 42	$ 16

Revenue - Additional Informatio

Revenue - Additional Information (Details)	3 Months Ended
	Mar. 31, 2022USD ($)segment	Dec. 31, 2021USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative
Number of segments | segment	1
Contract asset	$ 0	$ 0
GlaxoSmithKline
Collaborative Arrangement and Arrangement Other than Collaborative
Contract liability	$ 2,800,000

Revenue - Vertex (Details)

Revenue - Vertex (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Jul. 31, 2017	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	May 31, 2021	Jul. 25, 2017
Revenue Recognition, Milestone Method
Revenue		$ 0	$ 5,000
Vertex
Revenue Recognition, Milestone Method
Proceeds from the sales of commercialization rights	$ 160,000,000
Proceeds from milestone settlement					$ 32,000,000
Vertex | Other Revenue
Revenue Recognition, Milestone Method
Revenue				$ 32,000,000
Disposed of by sale, not discontinued operations | Assets for synthesis and research and development for treating Cystic Fibrosis | Contingent consideration asset, After achievement of milestone events
Revenue Recognition, Milestone Method
Contingent consideration receivable						$ 90,000,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	Jan. 28, 2022	Jan. 01, 2022	Jun. 10, 2021	Jan. 05, 2021	Feb. 14, 2020	Aug. 15, 2019	Mar. 31, 2022
2014 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award
Additional shares issued under the plan (in shares)		1,389,561
Common stock available for future award grant (in shares)							2,026,725
Stock options
Share-based Compensation Arrangement by Share-based Payment Award
Total unrecognized compensation cost related to unvested options							$ 7
Total unrecognized compensation cost, weighted-average recognition period (years)							2 years 1 month 6 days
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award
Total unrecognized compensation cost, weighted-average recognition period (years)							2 years 1 month 6 days
Number of RSUs, granted (in shares)							1,005,575
Total unrecognized compensation cost related to restricted stock units							$ 5.2
Restricted stock units | 2019 RSU | Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting percentage						65.00%
Restricted stock units | 2020 RSU
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period (in years)					3 years
Number of RSUs, granted (in shares)					400,000
Share-based payment award, vested							300,000
Restricted stock units | 2020 RSU | Tranche One
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting percentage					33.00%
Restricted stock units | 2020 RSU | Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting percentage					33.00%
Restricted stock units | 2020 RSU | Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting percentage					33.00%
Restricted stock units | January 2021 RSU
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period (in years)				3 years
Number of RSUs, granted (in shares)				300,000
Share-based payment award, vested							100,000
Restricted stock units | June 2021 June RSU
Share-based Compensation Arrangement by Share-based Payment Award
Number of RSUs, granted (in shares)			200,000
Share-based payment award, vested							100,000
Restricted stock units | 2022 RSU
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period (in years)	3 years
Number of RSUs, granted (in shares)	700,000
Restricted stock units | 2022 PSU
Share-based Compensation Arrangement by Share-based Payment Award
Number of RSUs, granted (in shares)							300,000
Minimum | Stock options
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period (in years)							1 year
Median | Stock options
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period (in years)							3 years
Maximum | Stock options
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period (in years)							4 years
Awards expiration period (in years)							10 years

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Expense Related to All Stock Based Awards Recognized in Statements of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award
Total stock-based compensation expense	$ 2,111	$ 3,431
Research and development
Share-based Compensation Arrangement by Share-based Payment Award
Total stock-based compensation expense	950	1,851
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award
Total stock-based compensation expense	$ 1,161	$ 1,580

Stock-Based Compensation - Esti

Stock-Based Compensation - Estimated Weighted-Average Assumptions of Options Granted (Details)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Expected volatility	70.33%	69.71%
Expected term	6 years	6 years
Risk-free interest rate	2.33%	0.54%
Expected dividend yield	0.00%	0.00%

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Value of Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Weighted average grant date fair value of options granted, per option (in dollars per share)	$ 2.47	$ 7.87
Aggregate grant date fair value of options vested during the period	$ 1,909	$ 2,066
Total cash received from exercises of stock options	0	89
Total intrinsic value of stock options exercised	$ 0	$ 42

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)$ / sharesshares
Number of Option Shares
Number of options, Outstanding beginning balance (in shares) | shares	5,197,320
Number of options, Granted (in shares) | shares	29,200
Number of options, Exercised (in shares) | shares	0
Number of options, Forfeited or expired (in shares) | shares	(178,506)
Number of options, Outstanding ending balance (in shares) | shares	5,048,014
Number of options, Exercisable (in shares) | shares	3,985,474
Number of options, Vested and expected to vest (in shares) | shares	4,968,980
Weighted Average Exercise Price per Share
Weighted average exercise price per share, Outstanding at beginning of year (in dollars per share) | $ / shares	$ 14.21
Weighted average exercise price per share, Granted (in dollars per share) | $ / shares	3.88
Weighted average exercise price per share, Exercised (in dollars per share) | $ / shares	0
Weighted average exercise price per share, Forfeited or expired (in dollars per share) | $ / shares	15.70
Weighted average exercise price per share, Outstanding ending balance (in dollars per share) | $ / shares	14.09
Weighted average exercise price per share, Exercisable (in dollars per share) | $ / shares	14.72
Weighted average exercise price per share, Vested and expected to vest (in dollars per share) | $ / shares	$ 14.13
Weighted Average Remaining Contractual Term (In years)
Weighted average remaining contractual term, Outstanding	5 years 9 months 18 days
Weighted average remaining contractual term, Exercisable	5 years 2 months 12 days
Weighted average remaining contractual term, Vested and expected to vest	5 years 9 months 18 days
Aggregate Intrinsic Value
Aggregate intrinsic value, Outstanding | $	$ 2
Aggregate intrinsic value, Exercisable | $	2
Aggregate intrinsic value, Vested and expected to vest | $	$ 2
Estimated forfeiture rate (percent)	7.00%

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of RSU Activity (Details) - Restricted stock units	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Number of RSUs
Number of RSUs, Outstanding beginning balance (in shares) | shares	628,192
Number of RSUs, Granted (in shares) | shares	1,005,575
Number of RSUs, Released (in shares) | shares	(214,315)
Number of RSUs, Forfeited (in shares) | shares	(29,992)
Number of RSUs, Outstanding ending balance (in shares) | shares	1,389,460
Weighted- Average Grant Date Fair Value
Weighted average grant date fair value, Outstanding at beginning of year (in dollars per share) | $ / shares	$ 10.78
Weighted average grant date fair value, Granted (in dollars per share) | $ / shares	2.89
Weighted average grant date fair value, Released (in dollars per share) | $ / shares	11.81
Weighted average grant date fair value, Forfeited (in dollars per share) | $ / shares	9.40
Weighted average grant date fair value, Outstanding at ending of year (in dollars per share) | $ / shares	$ 4.94

Loss Per Share - Computation of

Loss Per Share - Computation of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss applicable to common stockholders - basic and diluted (in shares)	$ (37,728)	$ (22,669)
Denominator:
Weighted-average shares outstanding - basic (in shares)	36,687	33,894
Weighted-average shares outstanding - diluted (in shares)	36,687	33,894
Net loss per share applicable to common stockholders - basic (in dollars per share)	$ (1.03)	$ (0.67)
Net loss per share applicable to common stockholders - diluted (in dollars per share)	$ (1.03)	$ (0.67)
Stock options
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:
Anti-dilutive stock options, restricted stock units, and warrants (in shares)	5,048	5,366
Restricted stock units
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:
Anti-dilutive stock options, restricted stock units, and warrants (in shares)	1,389	822
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share
Warrants to purchase common shares (in shares)	1,800
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:
Anti-dilutive stock options, restricted stock units, and warrants (in shares)	16,311	61
Series X1 Preferred Stock
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:
Anti-dilutive stock options, restricted stock units, and warrants (in shares)	13,997	0

Commitments - Additional Inform

Commitments - Additional Information (Details) ft² in Thousands, $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2019USD ($)	Mar. 31, 2022USD ($)ft²extension	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)	Jan. 01, 2019USD ($)
Loss Contingencies [Line Items]
Operating lease liability					$ 16,900
Lease liability, current portion		$ 1,216		$ 1,155
Lease liability, net of current portion		13,574		13,910
Operating lease right-of-use assets		8,469		$ 8,585	9,500
Reduction to accrued rent					2,900
Reduction to incentive to lessee					$ 4,500
Operating lease, expense		600
Operating lease, payments		$ 764	$ 742
Weighted average remaining lease term (in years)		6 years 9 months	7 years 9 months
Weighted average discount rate (in percent)		13.08%	13.08%
Property Located At 65 Hayden Avenue, Lexington, Massachusetts
Loss Contingencies [Line Items]
Area of real estate | ft²		56
Term of contract (in years)					10 years
Number of extensions (in year) | extension		2
Length of extension (in year)		5 years
Annual base rent amount	$ 2,800
Annual rent increase, percent		3.00%
Abatement of base rent amount		$ 500

Open Market Sale Agreement (Det

Open Market Sale Agreement (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 07, 2021	Nov. 05, 2020	Mar. 01, 2019
Subsidiary, Sale of Stock
Receivables from shares sold	$ 500,000
Maximum
Subsidiary, Sale of Stock
Sale of stock, authorized amount			$ 100,000,000
ATM
Subsidiary, Sale of Stock
Sale of stock, authorized amount				$ 50,000,000
Number of shares issued in transaction (in shares)	165,323
Proceeds from issuance of common stock	$ 2,000,000
Sale of stock, commission rate (in percent)	3.00%			3.00%
ATM | Minimum
Subsidiary, Sale of Stock
Sale of stock, authorized amount		$ 50,000,000	$ 50,000,000

2021 Sale of Common and Prefe_3

2021 Sale of Common and Preferred Stock, Warrants and Royalty Interest (Details) - USD ($) $ / shares in Units, $ in Millions	Nov. 03, 2021	Nov. 30, 2021	Dec. 31, 2021	Mar. 31, 2022
Class of Stock
Warrant to an exercise price (in dollars per share)		$ 2.88
Fair value of the royalty Interest			$ 4.8
Warrant liabilities, long-term - related party			7.1	$ 7.7
Deferred revenue			2.2	2.2
Unrealized loss on warrant liabilities - related party			0.5
RA Capital Healthcare Fund, L.P.
Class of Stock
Percentage of warrants owned	16.20%
Payments to acquire warrants	$ 30
RA Capital Healthcare Fund, L.P. | Maximum
Class of Stock
Percentage of warrants owned	23.10%
RA Capital Healthcare Fund, L.P. | Concert Pharmaceuticals Inc
Class of Stock
Ownership interest (percent)	5.00%
Investor | RA Capital Healthcare Fund, L.P.
Class of Stock
Warrants to purchase common shares (in shares)	7,500
AVP-786 | Investor
Class of Stock
Initial royalty entitlements (percent)		35.00%
AVP-786 | Investor | Tranche One
Class of Stock
Potential increase to royalty entitlements (percent)		7.50%
AVP-786 | Investor | Tranche Two
Class of Stock
Potential increase to royalty entitlements (percent)		7.50%
Series X1 Preferred Stock
Class of Stock
Preferred stock, convertible, share conversion rate		1,000
Series X1 Preferred Stock | Director
Class of Stock
Warrants to purchase common shares (in shares)		32,500
Warrants | Tranche One
Class of Stock
Valuation model which resulted in a fair value			8.5	8.8
Warrants | Tranche Two
Class of Stock
Valuation model which resulted in a fair value			6.9	$ 7.8
Private Placement
Class of Stock
Gross proceeds from the sales of stock		$ 65
Proceeds from issuance of common stock		64.4
Deferred offering costs		$ 0.6
Private Placement | Series X1 Preferred Stock
Class of Stock
Number of shares issued in transaction (in shares)		13,997
Warrants to purchase common shares (in shares)		16,250
Proceeds from issuance of common stock			40.3
Private Placement | Series X1 Preferred Stock | Investor | RA Capital Healthcare Fund, L.P.
Class of Stock
Number of shares issued in transaction (in shares)	7,500
Private Placement | Series X1 Preferred Stock | Warrant Tranche One
Class of Stock
Warrants to purchase common shares (in shares)		8,125
Warrant exercise price (in dollars per share)		$ 5.34
Private Placement | Series X1 Preferred Stock | Warrant Tranche Two
Class of Stock
Warrants to purchase common shares (in shares)		8,125
Warrant exercise price (in dollars per share)		$ 7.35
Private Placement | Common Stock
Class of Stock
Number of shares issued in transaction (in shares)		2,253,000
Proceeds from issuance of common stock			6.5
Private Placement | Warrants | Warrant Tranche One
Class of Stock
Proceeds from issuance of common stock			7.5
Private Placement | Warrants | Warrant Tranche Two
Class of Stock
Proceeds from issuance of common stock			$ 5.9

2021 Sale of Common and Prefe_4

2021 Sale of Common and Preferred Stock, Warrants and Royalty Interest - Fair Value Assumptions Related To The Warrants (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Class of Stock
Expected volatility	70.33%	69.71%
Expected term	6 years	6 years
Risk-free interest rate	2.33%	0.54%
Expected dividend yield	0.00%	0.00%
Warrants | Tranche One
Class of Stock
Expected volatility	74.42%		75.90%
Expected term	2 years 4 months 17 days		2 years 8 months 4 days
Risk-free interest rate	2.37%		0.97%
Expected dividend yield	0.00%		0.00%
Warrants | Tranche Two
Class of Stock
Expected volatility	78.21%		76.40%
Expected term	2 years 6 months 18 days		2 years 9 months 18 days
Risk-free interest rate	2.37%		0.97%
Expected dividend yield	0.00%		0.00%