Biohaven (BHVN) 10-Q 14 Nov 23 2023 Q3 Quarterly report Financial data

COVER

COVER - shares	9 Months Ended
	Sep. 30, 2023	Nov. 10, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-41477
Entity Registrant Name	Biohaven Ltd.
Entity Incorporation, State or Country Code	D8
Entity Address, Address Line One	c/o Biohaven Pharmaceuticals, Inc.
Entity Address, Address Line Two	215 Church Street
Entity Address, City or Town	New Haven
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06510
City Area Code	203
Local Phone Number	404-0410
Title of 12(b) Security	Common Shares, no par value
Trading Symbol	BHVN
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		80,233,656
Entity Central Index Key	0001935979
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 111,697	$ 204,877
Marketable securities	128,899	260,464
Prepaid expenses	33,936	20,945
Income tax receivable	13,073	46,139
Restricted cash held on behalf of Former Parent	28	35,212
Other current assets	22,937	19,331
Total current assets	310,570	586,968
Property and equipment, net	17,669	17,512
Intangible assets	18,400	18,400
Goodwill	1,390	1,390
Other non-current assets	34,707	37,513
Total assets	382,736	661,783
Current liabilities:
Accounts payable	9,515	10,703
Due to Former Parent	28	35,212
Accrued expenses and other current liabilities	52,634	44,106
Total current liabilities	62,177	90,021
Long-term operating lease liability	28,286	30,581
Other non-current liabilities	2,267	2,410
Total liabilities	92,730	123,012
Commitments and contingencies (Note 11)
Shareholders' Equity:
Preferred shares, no par value; 10,000,000 shares authorized, no shares issued and outstanding as of September 30, 2023 and December 31, 2022	0	0
Common shares, no par value; 200,000,000 shares authorized as of September 30, 2023 and December 31, 2022; 68,364,143 and 68,190,479 shares issued and outstanding as of September 30, 2023 and December 31, 2022, respectively	618,761	615,742
Additional paid-in capital	25,623	13,869
Accumulated deficit	(354,536)	(91,124)
Accumulated other comprehensive income	158	284
Total shareholders' equity	290,006	538,771
Total liabilities and shareholders' equity	$ 382,736	$ 661,783

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock issued (share)	0	0
Preferred stock outstanding (share)	0	0
Common shares, par value (in dollars per share)	$ 0	$ 0
Common shares, authorized (shares)	200,000,000	200,000,000
Common shares, issued (shares)	68,364,143	68,190,479
Common shares, outstanding (shares)	68,364,143	68,190,479

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 95,517	$ 52,845	$ 238,468	$ 300,028
General and administrative	15,030	14,792	43,872	54,492
Total operating expenses	110,547	67,637	282,340	354,520
Loss from operations	(110,547)	(67,637)	(282,340)	(354,520)
Other income (expense), net	4,686	0	18,757	(71)
Loss before (benefit) provision for income taxes	(105,861)	(67,637)	(263,583)	(354,591)
(Benefit) provision for income taxes	(3,287)	1,216	(171)	14,581
Net loss	$ (102,574)	$ (68,853)	$ (263,412)	$ (369,172)
Net loss per share attributable to common shareholders of Biohaven Ltd. — basic (in dollars per share)	$ (1.50)	$ (1.75)	$ (3.86)	$ (9.38)
Net loss per share attributable to common shareholders of Biohaven Ltd. — diluted (in dollars per share)	$ (1.50)	$ (1.75)	$ (3.86)	$ (9.38)
Weighted average common shares outstanding—basic (in shares)	68,320,125	39,375,944	68,258,757	39,375,944
Weighted average common shares outstanding—diluted (in shares)	68,320,125	39,375,944	68,258,757	39,375,944
Net loss	$ (102,574)	$ (68,853)	$ (263,412)	$ (369,172)
Other comprehensive income (loss), net of tax	138	0	(126)	0
Comprehensive loss	$ (102,436)	$ (68,853)	$ (263,538)	$ (369,172)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (263,412)	$ (369,172)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash share-based compensation expense	12,916	77,927
Acquisition of IPR&D asset	0	93,747
Depreciation and amortization	5,018	1,042
Issuance of Former Parent common shares as payment for license and consulting agreements	0	1,779
Other non-cash items	(4,696)	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets	28,428	(15,666)
Accounts payable	(1,188)	(44)
Accrued expenses and other liabilities	6,090	(11,895)
Net cash used in operating activities	(216,844)	(222,282)
Cash flows from investing activities:
Proceeds from sales and maturities of marketable securities	219,144	0
Purchases of marketable securities	(82,822)	0
Purchases of property and equipment	(2,578)	(5,774)
Payment for IPR&D asset acquisition	0	(35,000)
Net cash provided by (used in) investing activities	133,744	(40,774)
Cash flows from financing activities:
Net transfers from Former Parent	0	237,417
Change in restricted cash due to Former Parent	(35,184)	0
Other	1,857	0
Net cash (used in) provided by financing activities	(33,327)	237,417
Effects of exchange rates on cash, cash equivalents, and restricted cash	(187)	0
Net decrease in cash, cash equivalents, and restricted cash	(116,614)	(25,639)
Cash, cash equivalents, and restricted cash at beginning of period	242,604	77,057
Cash, cash equivalents, and restricted cash at end of period	$ 125,990	$ 51,418

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business and Basis of Presentation	Nature of the Business and Basis of Presentation Biohaven Ltd. (“we,” “us," "our," "Biohaven" or the “Company”) was incorporated in Tortola, British Virgin Islands in May 2022. Biohaven is a global clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of life-changing therapies to treat a broad range of rare and common diseases. The Company is advancing a pipeline of therapies for diseases, many of which have little or no treatment options, leveraging its proven drug development capabilities and proprietary platforms, including Kv7 ion channel modulation for epilepsy and neuronal hyperexcitability, glutamate modulation for Obsessive-Compulsive Disorder ("OCD") and spinocerebellar ataxia ("SCA"), myostatin inhibition for neuromuscular diseases and metabolic disorders, and brain-penetrant Tyrosine Kinase 2/Janus Kinase 1 ("TYK2/JAK1") inhibition for neuroinflammatory disorders. Biohaven's portfolio of early- and late-stage product candidates also includes research programs focused on TRPM3 channel activation for neuropathic pain, CD-38 antibody recruiting, bispecific molecules for multiple myeloma, antibody drug conjugates ("ADCs"), and targeted extracellular protein degradation platform technology ("MoDE") with potential application in neurological disorders, cancer, and autoimmune diseases. The Company is subject to risks and uncertainties common to companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts may require additional capital, additional personnel and infrastructure, and further regulatory and other capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. Separation from Biohaven Pharmaceutical Holding Company Ltd. On May 9, 2022, Biohaven Pharmaceutical Holding Company Ltd. (the "Former Parent"), Pfizer Inc. (“Pfizer”) and Bulldog (BVI) Ltd., a wholly owned subsidiary of Pfizer (“Merger Sub”), entered into an Agreement and Plan of Merger (the “Merger Agreement”), which provided for the acquisition by Pfizer of the Former Parent through the merger of Merger Sub with and into the Former Parent (the “Merger”). In connection with the Merger Agreement, the Former Parent and Biohaven entered into a Separation and Distribution Agreement, dated as of May 9, 2022 (the “Distribution Agreement”). In connection with the Distribution Agreement, the Board of Directors of the Former Parent approved and directed the Former Parent’s management to effect the Spin-Off (as defined below) of the business, operations, and activities that are not the CGRP Business (as defined below), including the Kv7 ion channel activators, glutamate modulation, Myeloperoxidase ("MPO") inhibition and myostatin inhibition platforms, preclinical product candidates, and certain corporate infrastructure currently owned by the Former Parent. To implement the Spin-Off, the Former Parent transferred the related license agreements, intellectual property and corporate infrastructure, including certain non-commercial employee agreements, share based awards and other corporate agreements (the "Business") to Biohaven, through a series of internal restructuring transactions. Descriptions of historical business activities in these Notes to Condensed Consolidated Financial Statements are presented as if these transfers had already occurred, and the Former Parent’s activities related to such assets and liabilities had been performed by the Company. On October 3, 2022, the Former Parent completed the distribution (the “Distribution”) to holders of its common shares of all of the outstanding common shares of Biohaven and the spin-off of Biohaven from the Former Parent (the “Spin-Off”) described in Biohaven’s Information Statement (the “Information Statement”) attached as Exhibit 99.1 to Biohaven’s Registration Statement on Form 10, as amended (Reg. No. 001-41477), which was declared effective by the Securities and Exchange Commission (the "SEC") on September 22, 2022. Each holder of Former Parent common shares received one common share of Biohaven for every two Former Parent common shares held of record as of the close of business on September 26, 2022. In the Distribution, an aggregate of 35,840,459 Biohaven common shares were issued. The aggregate number of common shares issued in connection with the Distribution did not include 2,611,392 common shares to be issued in connection with Former Parent stock options that were exercised on October 3, 2022 and 924,093 common shares to be issued in connection with Former Parent restricted stock units that vested on October 3, 2022. As a result of the Distribution, Biohaven became an independent, publicly traded company. Collectively, we refer to the Distribution and Spin-Off throughout this Quarterly Report on Form 10-Q as the "Separation." The Separation generally resulted in (a) the Company directly or indirectly owning, assuming, or retaining certain assets and liabilities of the Former Parent and its subsidiaries related to the Former Parent’s pipeline assets and businesses and (b) the Former Parent directly or indirectly owning, assuming, or retaining all other assets and liabilities, including those associated with the Former Parent’s platform for the research, development, manufacture and commercialization of calcitonin gene-related receptor antagonists, including rimegepant, zavegepant and the Heptares Therapeutics Limited preclinical CGRP portfolio and related assets (the “CGRP Business”). In connection with the Separation, the Company entered into various agreements relating to transition services, licenses and certain other matters with the Former Parent. For additional information regarding these agreements, see Note 13, "Related Party Transactions." Basis of Presentation On October 3, 2022, the Company became a standalone publicly traded company, and its financial statements are now presented on a condensed consolidated basis. Prior to the Separation on October 3, 2022, the Company’s historical combined financial statements were prepared on a standalone basis and were derived from the Former Parent's consolidated financial statements and accounting records. The financial statements for all periods presented, including the historical results of the Company prior to October 3, 2022, are now referred to as "Condensed Consolidated Financial Statements," and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the SEC. Periods Prior to the Separation For periods prior to the Separation, the condensed consolidated financial statements present, on a historical basis, the combined assets, liabilities, expenses and cash flows directly attributable to the Business, which have been prepared from the Former Parent’s consolidated financial statements and accounting records, and are presented on a stand-alone basis as if the operations had been conducted independently from the Former Parent. The condensed consolidated financial statements of operations and comprehensive loss for periods prior to the Separation include all costs directly related to the Business, including costs for facilities, functions and services utilized by the Company. The condensed consolidated statements of operations and comprehensive loss for periods prior to the Separation also include allocations for various expenses related to the Former Parent’s corporate functions, including research and development, human resources, information technology, facilities, tax, shared services, accounting, finance and legal. These expenses were allocated on the basis of direct usage or benefit when specifically identifiable, with the remainder allocated on a proportional cost allocation method primarily based on employee labor hours or direct expenses. Management believes the assumptions underlying the condensed consolidated financial statements, including the expense methodology and resulting allocation, are reasonable for all periods presented. However, the allocations may not include all of the actual expenses that would have been incurred by the Company and may not reflect its consolidated results of operations, financial position and cash flows had it been a standalone company during the periods presented. It is not practicable to estimate actual costs that would have been incurred had the Company been a standalone company and operated as an unaffiliated entity during the periods presented. Actual costs that might have been incurred had the Company been a standalone company would depend on a number of factors, including the chosen organizational structure, what corporate functions the Company might have performed directly or outsourced and strategic decisions the Company might have made in areas such as executive management, legal and other professional services, and certain corporate overhead functions. The income tax amounts in the condensed consolidated financial statements for periods prior to the separation were calculated on a separate return method and presented as if the Company’s operations were separate taxpayers in the respective jurisdiction. Therefore, tax expense, cash tax payments, and items of current and deferred taxes may not be reflective of the Company’s actual tax balances prior to or subsequent to the Distribution. For periods prior to the Separation, the Company's equity balance in these condensed consolidated financial statements represents the excess of total assets over liabilities. Net investment from Former Parent is primarily impacted by contributions from the Former Parent, which are the result of net funding provided by or distributed to the Former Parent. As a result of the Separation, the Company’s Net investment from Former Parent balance was reclassified to common shares. The Net investment from Former Parent balance reclassified to common shares during the fourth quarter of 2022 included Separation-related adjustments of $27,811. The adjustments related primarily to differences in the amount of assets and liabilities transferred to the Company upon the Separation and the amount of the transferred assets and liabilities reported in the Company’s combined balance sheet as of September 30, 2022. Going Concern In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the condensed consolidated financial statements are issued. Through November 14, 2023, the Company has funded its operations primarily with funding from the Former Parent, proceeds from the public offering of its common shares (refer to Note 7, Shareholders' Equity), and the cash contribution received from the Former Parent at the Separation (refer to Note 13, Related Party Transactions ) The Company has incurred recurring losses since its inception and expects to continue to generate operating losses for the foreseeable future. As of the date of issuance of these condensed consolidated financial statements, the Company expects its existing cash, cash equivalents and marketable securities will be sufficient to fund operating expenses, financial commitments and other cash requirements for at least one year after the issuance date of these financial statements. To execute its business plans, the Company will require funding to support its continuing operations and pursue its growth strategy. Until such time as the Company can generate significant revenue from product sales or royalties, if ever, it expects to finance its operations through the sale of public or private equity, debt financings or other capital sources, including collaborations with other companies or other strategic transactions. The Company may not be able to obtain financing on acceptable terms, or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s shareholders. If the Company is unable to obtain funding, the Company could be forced

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Our significant accounting policies are described in Note 2, "Summary of Significant Accounting Policies" to the consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2022 (the "2022 Form 10-K"). Updates to our accounting policies are discussed below in this Note 2. Unaudited Interim Condensed Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information. The accompanying unaudited condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. The accompanying year-end condensed consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2023, the results of its operations for the three and nine months ended September 30, 2023 and 2022, and its cash flows for the nine months ended September 30, 2023 and 2022. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods or any future year or period. The financial information included herein should be read in conjunction with the financial statements and notes in the Company's Annual Report on Form 10-K for the year ended December 31, 2022. Reclassifications Certain items in the prior period’s condensed consolidated financial statements have been reclassified to conform to the current year presentation. Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of income and expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, determining the allocations of costs and expenses from the Former Parent and the accrual for research and development expenses. In addition, management’s assessment of the Company’s ability to continue as a going concern involves the estimation of the amount and timing of future cash inflows and outflows. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates. Restricted Cash Restricted cash held on behalf of the Former Parent on the consolidated balance sheet as of September 30, 2023 represents cash held by the Company on behalf of the Former Parent related to the execution of the United States Distribution Services Agreement (the “Distribution Services Agreement”). Pursuant to the terms of the Distribution Services Agreement, which was entered into by the Company and the Former Parent in connection with the Separation, the Company is continuing to serve as the Former Parent’s distributor and agent for the distribution of the pharmaceutical product Nurtec ODT in the United States. As of September 30, 2023, the Company recorded a related payable of $28 as Due to Former Parent on the consolidated balance sheet as the balance was legally payable to the Former Parent. Refer to Note 13, "Related Party Transactions" for further information on the agreements entered into by the Company and the Former Parent in connection with the Separation. Restricted cash included in other current assets as of September 30, 2023 consisted primarily of restricted cash held in escrow for the cash portion of consideration to be paid in connection with our license agreement with Hangzhou Highlightll Pharmaceutical Co. Ltd. ("Highlightll") upon the completion of certain post-closing activities, which were not completed as of September 30, 2023. Restricted cash included in other current assets also includes employee contributions to the Company's employee share purchase plan held for future purchases of the Company's outstanding shares. The Company did not have an employee share purchase plan as of September 30, 2022. Restricted cash included in other non-current assets in the consolidated balance sheets represents collateral held by banks for a letter of credit ("LOC") issued in connection with the leased office space in Yardley, Pennsylvania and a LOC issued in connection with the leased office space in Cambridge, Massachusetts. See Note 11, ‘‘Commitments and Contingencies’’ for additional information on the real estate leases. The following represents a reconciliation of cash and cash equivalents in the condensed consolidated balance sheets to total cash, cash equivalents and restricted cash as of September 30, 2023 and September 30, 2022, respectively, in the condensed consolidated statements of cash flows: As of September 30, 2023 As of September 30, 2022 Cash and cash equivalents $ 111,697 $ 50,668 Restricted cash held on behalf of Former Parent 28 — Restricted cash (included in other current assets) 11,890 — Restricted cash (included in other non-current assets) 2,375 750 Total cash, cash equivalents and restricted cash at the end of the period in the condensed consolidated statement of cash flows $ 125,990 $ 51,418 Recently Issued Accounting Pronouncements In June 2022, the FASB issued ASU No. 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions, to clarify the guidance in Topic 820 when measuring the fair value of an equity security subject to contractual restrictions that prohibit the sale of an equity security. The ASU also introduced new disclosure requirements for equity securities subject to contractual sale restrictions that are measured at fair value in accordance with Topic 820. The amendments in ASU 2022-03 are effective for fiscal years beginning after December 15, 2023. The Company does not expect ASU No. 2022-03 to have a material effect on its consolidated financial statements.

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities The amortized cost, gross unrealized holding gains, gross unrealized holding losses and fair value of debt securities available-for-sale by type of security at September 30, 2023 and December 31, 2022 were as follows: Amortized Cost Allowance for Credit Losses Net Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2023 Debt securities U.S. corporate bonds $ 64,635 $ — $ 64,635 $ — $ (62) $ 64,573 Foreign corporate bonds 24,623 — 24,623 — (19) 24,604 U.S. treasury bills 39,759 — 39,759 3 — 39,762 U.S. agency bonds 4,965 — 4,965 — (5) 4,960 Total $ 133,982 $ — $ 133,982 $ 3 $ (86) $ 133,899 December 31, 2022 Debt securities U.S. corporate bonds $ 142,697 $ — $ 142,697 $ 25 $ (135) $ 142,587 Foreign corporate bonds 36,766 — 36,766 9 (32) 36,743 U.S. treasury bills 89,308 — 89,308 17 (5) 89,320 U.S. agency bonds 41,734 — 41,734 — (24) 41,710 Total $ 310,505 $ — $ 310,505 $ 51 $ (196) $ 310,360 The fair value of debt securities available-for-sale by classification in the condensed consolidated balance sheets was as follows: September 30, 2023 December 31, 2022 Cash and cash equivalents $ 5,000 $ 49,896 Marketable securities 128,899 260,464 Total $ 133,899 $ 310,360 The net amortized cost and fair value of debt securities available-for-sale at September 30, 2023 and December 31, 2022 are shown below by contractual maturity. Actual maturities may differ from contractual maturities because securities may be restructured, called or prepaid, or the Company intends to sell a security prior to maturity. September 30, 2023 December 31, 2022 Net Amortized Cost Fair Value Net Amortized Cost Fair Value Due to mature: Less than one year $ 133,982 $ 133,899 $ 310,505 $ 310,360 Summarized below are the debt securities available-for-sale the Company held at September 30, 2023 and December 31, 2022 that were in an unrealized loss position, aggregated by the length of time the investments have been in that position: Less than 12 months Number of Securities Fair Value Unrealized Losses September 30, 2023 Debt securities U.S. corporate bonds 11 $ 64,573 $ (62) Foreign corporate bonds 3 24,604 (19) U.S. treasury bills 2 9,882 — U.S. agency bonds 1 4,960 (5) Total 17 $ 104,019 $ (86) December 31, 2022 Debt securities U.S. corporate bonds 16 $ 104,508 $ (135) Foreign corporate bonds 3 31,886 (32) U.S. treasury bills 1 9,762 (5) U.S. agency bonds 4 41,710 (24) Total 24 $ 187,866 $ (196) The Company did not have any investments in a continuous unrealized loss position for more than twelve months as of September 30, 2023 and December 31, 2022. The Company reviewed the securities in the table above and concluded that they are performing assets, considering factors such as the credit quality of the investment security based on research performed by external rating agencies and the prospects of realizing the carrying value of the security based on the investment’s current prospects for recovery. As of September 30, 2023, the Company did not intend to sell these securities and did not believe it was more likely than not that it would be required to sell these securities prior to the anticipated recovery of their amortized cost basis. Net Investment Income Gross investment income includes income from debt securities available-for-sale, money-market funds, cash and restricted cash. Sources of net investment income included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2023 Gross investment income $ 3,831 $ 12,231 Investment expenses (65) (203) Net investment income (excluding net realized capital losses) 3,766 12,028 Net realized capital losses — (39) Net investment income $ 3,766 $ 11,989 The Company had no investment income during the three and nine months ended September 30, 2022. We utilize the specific identification method in computing realized gains and losses. The proceeds from the sale of available-for-sale debt securities and the related gross realized capital losses for the three and nine months ended September 30, 2023 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2023 Proceeds from sales $ — $ 4,920 Gross realized capital losses — $ 39 The Company had no proceeds from the sale of available-for-sale debt securities and the related gross realized capital gains and losses for the three and nine months ended September 30, 2022.

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	Fair Value of Financial Assets and Liabilities The preparation of the Company’s condensed consolidated financial statements in accordance with GAAP requires certain assets and liabilities to be reflected at their fair value and others to be reflected on another basis, such as an adjusted historical cost basis. In this note, the Company provides details on the fair value of financial assets and liabilities and how it determines those fair values. Financial Instruments Measured at Fair Value on the Condensed Consolidated Balance Sheets Certain assets of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1 — Quoted prices in active markets for identical assets or liabilities. • Level 2 — Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3 — Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. Financial assets measured at fair value on a recurring basis on the condensed consolidated balance sheets at September 30, 2023 and December 31, 2022 were as follows: Fair Value Measurement Using: Balance Sheet Classification Type of Instrument Level 1 Level 2 Level 3 Total September 30, 2023 Assets: Cash and cash equivalents Money market funds $ 29,794 $ — $ — $ 29,794 Cash and cash equivalents U.S. treasury bills — 5,000 — 5,000 Marketable securities U.S. treasury bills 9,920 24,842 — 34,762 Marketable securities U.S. corporate bonds — 64,573 — 64,573 Marketable securities U.S. agency bonds — 4,960 — 4,960 Marketable securities Foreign corporate bonds — 24,604 — 24,604 Other non-current assets Money market funds 1,875 — — 1,875 Total assets $ 41,589 $ 123,979 $ — $ 165,568 December 31, 2022 Assets: Cash and cash equivalents Money market funds $ 72,866 $ — $ — $ 72,866 Cash and cash equivalents U.S. treasury bills — 39,948 — 39,948 Cash and cash equivalents U.S. corporate bonds — 9,948 — 9,948 Marketable securities U.S. treasury bills — 49,372 — 49,372 Marketable securities U.S. corporate bonds — 132,639 — 132,639 Marketable securities U.S. agency bonds — 41,710 — 41,710 Marketable securities Foreign corporate bonds — 36,743 — 36,743 Total assets $ 72,866 $ 310,360 $ — $ 383,226 The Company had no financial liabilities measured at fair value on a recurring basis on the condensed consolidated balance sheets at September 30, 2023 and December 31, 2022. There were no securities transferred into or out of Level 3 during the three and nine months ended September 30, 2023 or 2022. The following is a description, including valuation methodology, of the financial assets and liabilities measured at fair value on a recurring basis: Cash Equivalents Cash equivalents at September 30, 2023 consisted of cash invested in short-term money market funds and debt securities with an original maturity of 90 days or less at the date of purchase. The carrying value of cash equivalents approximates fair value as maturities are less than three months. When quoted prices are available in an active market, cash equivalents are classified in Level 1 of the fair value hierarchy. Fair values of cash equivalent instruments that do not trade on a regular basis in active markets are classified as Level 2. Marketable Securities Quoted prices for identical assets in active markets are considered Level 1 and consist of on-the-run U.S. Treasuries and money market funds. The fair values of the Company’s Level 2 debt securities are obtained from quoted

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Property and Equipment, Net Property and equipment, net consisted of the following: As of September 30, 2023 As of December 31, 2022 Building and land $ 11,728 $ 11,728 Leasehold improvements 680 569 Computer hardware and software 780 780 Office and lab equipment 9,148 5,501 Furniture and fixtures 1,491 1,202 $ 23,827 $ 19,780 Accumulated depreciation (7,335) (4,914) 16,492 14,866 Equipment not yet in service 1,177 2,646 Property and equipment, net $ 17,669 $ 17,512 Depreciation expense was $857 and $2,421 for the three and nine months ended September 30, 2023 and $230 and $718 for the three and nine months ended September 30, 2022, respectively. As of September 30, 2023 and December 31, 2022, computer software costs included in property and equipment were $760 and $760, net of accumulated amortization of $654 and $464, respectively. Amortization expense for capitalized computer software costs were not material for the three and nine months ended September 30, 2023 or 2022. Equipment not yet in service primarily consisted of lab equipment that had not been placed into service as of September 30, 2023 and December 31, 2022. Other Non-current Assets Other non-current assets consisted of the following: As of September 30, 2023 As of December 31, 2022 Operating lease right-of-use assets $ 32,330 $ 34,928 Other 2,377 2,585 Other non-current assets $ 34,707 $ 37,513 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following: As of September 30, 2023 As of December 31, 2022 Accrued employee compensation and benefits $ 13,977 $ 14,603 Accrued clinical trial costs 27,945 17,788 Operating lease liability - current portion 3,281 3,019 Other accrued expenses and other current liabilities 7,431 8,696 Accrued expenses and other current liabilities $ 52,634 $ 44,106

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2023
Business Combination and Asset Acquisition [Abstract]
Acquisitions	Acquisitions Kv7 Platform Acquisition In April 2022, the Company closed the acquisition from Knopp Biosciences LLC (“Knopp”) of Channel Biosciences, LLC (“Channel”), a wholly owned subsidiary of Knopp owning the assets of Knopp’s Kv7 channel targeting platform (the “Kv7 Platform Acquisition”), pursuant to a Membership Interest Purchase Agreement (the “Purchase Agreement”), dated February 24, 2022. In consideration for the Kv7 Platform Acquisition, on April 4, 2022, the Company made an upfront payment comprised of $35,000 in cash and 493,254 common shares, valued at approximately $58,747, issued through a private placement. The Company has also agreed to pay additional success-based payments comprised of (i) up to $325,000 based on developmental and regulatory milestones through approvals in the United States, EMEA and Japan for the lead asset, BHV-7000 (formerly known as KB-3061), (ii) up to an additional $250,000 based on developmental and regulatory milestones for the Kv7 pipeline development in other indications and additional country approvals, and (iii) up to $562,500 for commercial sales-based milestones of BHV-7000. Additionally, the Company has agreed to make scaled royalty payments in cash for BHV-7000 and the pipeline programs, with percentages starting at high single digits and peaking at low teens for BHV-7000 and starting at mid-single digits and peaking at low tens digits for the pipeline programs. The Company accounted for this purchase as an asset acquisition as substantially all of the fair value of the gross assets acquired was concentrated in a single identifiable asset, IPR&D. The IPR&D asset has no alternative future use and relates to intellectual property rights related to the Kv7 platform lead, now BHV-7000. There was no material value assigned to any other assets or liabilities acquired in the acquisition. As such, during the second quarter of 2022, the Company recorded a charge to research and development ("R&D") expense in the accompanying condensed consolidated statements of operations and comprehensive loss of $93,747. During the second quarter of 2022, the Company recorded $25,000 to R&D expense in the condensed consolidated statements of operations and comprehensive loss for a regulatory milestone payment made to Knopp. Excluding the milestone payment noted above, the Company has not recorded any of the possible contingent consideration payments to Knopp as a liability in the accompanying condensed consolidated balance sheet as none of the future events which would trigger a milestone payment were considered probable of occurring at September 30, 2023.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2023
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders' Equity Changes in shareholders’ equity for the three and nine months ended September 30, 2023 and September 30, 2022 were as follows: Common Shares Shares Amount Net Investment from Former Parent Additional Paid-in Capital Accumulated Deficit Accumulated Other Comprehensive Income Total Shareholders' Equity Balances as of December 31, 2022 68,190,479 $ 615,742 $ — $ 13,869 $ (91,124) $ 284 $ 538,771 Issuance of common shares under equity incentive plan 22,000 504 — (172) — — 332 Non-cash share-based compensation expense — — — 3,765 — — 3,765 Net loss — — — — (70,492) — (70,492) Other comprehensive loss — — — — — (118) (118) Balances as of March 31, 2023 68,212,479 616,246 — 17,462 (161,616) 166 472,258 Issuance of common shares under equity incentive plan and employee share purchase plan 104,474 1,264 — (470) — — 794 Non-cash share-based compensation expense — — — 4,695 — — 4,695 Net loss — — — — (90,346) — (90,346) Other comprehensive loss — — — — — (146) (146) Balances as of June 30, 2023 68,316,953 617,510 — 21,687 (251,962) 20 387,255 Issuance of common shares under equity incentive plan and employee share purchase plan 47,190 1,251 — (520) — — 731 Non-cash share-based compensation expense — — — 4,456 — — 4,456 Net loss — — — — (102,574) — (102,574) Other comprehensive income — — — — — 138 138 Balance as of September 30, 2023 68,364,143 $ 618,761 $ — $ 25,623 $ (354,536) $ 158 $ 290,006 Common Shares Shares Amount Net Investment from Former Parent Additional Paid-in Capital Accumulated Deficit Accumulated Other Comprehensive Income Total Shareholders' Equity Balance as of December 31, 2021 — $ — $ 34,691 $ — $ — $ — $ 34,691 Net loss — — (97,032) — — — (97,032) Net transfers from Former Parent — — 108,440 — — — 108,440 Balance as of March 31, 2022 — — 46,099 — — — 46,099 Net loss — — (203,287) — — — (203,287) Net transfers from Former Parent — — 182,186 — — — 182,186 Balance as of June 30, 2022 — — 24,998 — — — 24,998 Net loss — — (68,853) — — — (68,853) Net transfers from Former Parent — — 144,071 — — — 144,071 Balance as of September 30, 2022 — $ — $ 100,216 $ — $ — $ — $ 100,216 October 2023 Public Offering On October 5, 2023, the Company closed an underwritten public offering of 11,761,363 of its common shares, which included the exercise in full of the underwriters' option to purchase additional shares, at a price to the public of $22.00 per share. The net proceeds raised in the offering, after deducting underwriting discounts and expenses of the offering payable by Biohaven, were approximately $242,425. The Company intends to use the net proceeds received from the offering for general corporate purposes. Equity Distribution Agreement In October 2023, the Company entered into an equity distribution agreement pursuant to which the Company may offer and sell common shares having an aggregate offering price of up to $150,000 from time to time through or to the sales agent, acting as its agent or principal (the "Equity Distribution Agreement"). Sales of the Company's common shares, if any, will be made in sales deemed to be “at-the-market offerings”. The sales agent is not required to sell any specific amount of securities but will act as the Company's sales agent using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed terms between the sales agent and the Company. The Company currently plans to use the net proceeds from any at-the-market offerings of its common shares for general corporate purposes.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Shareholders’ equity included the following activity in accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2023: Three Months Ended September 30, 2023 Nine Months Ended September 30, 2023 Net unrealized investment gains (losses): Beginning of period balance $ (262) $ (145) Other comprehensive income before reclassifications (1) 178 22 Amounts reclassified from accumulated other comprehensive income (1)(2) — 39 Other comprehensive income (1) 178 61 End of period balance (84) (84) Foreign currency translation adjustments: Beginning of period balance 282 429 Other comprehensive loss (1) (40) (187) End of period balance 242 242 — Total beginning of period accumulated other comprehensive income 20 284 Total other comprehensive income (loss) 138 (126) Total end of period accumulated other comprehensive income $ 158 $ 158 (1) There was no tax on other comprehensive income (loss) and immaterial tax on amounts reclassified from accumulated other comprehensive income (loss) during the period. (2) Amounts reclassified from accumulated other comprehensive income (loss) for specifically identified debt securities are included in other income (expense), net on the condensed consolidated statement of operations. The Company had no accumulated other comprehensive income (loss) included in shareholders' equity as of September 30, 2022 and no amounts reclassified from accumulated other comprehensive income (loss) during the three and nine months ended September 30, 2022.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share Basic and diluted net loss per share attributable to common shareholders of Biohaven was calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Numerator: Net loss $ (102,574) $ (68,853) $ (263,412) $ (369,172) Denominator: Weighted average common shares outstanding—basic and diluted (1) 68,320,125 39,375,944 68,258,757 39,375,944 Net loss per share — basic and diluted $ (1.50) $ (1.75) $ (3.86) $ (9.38) (1) Prior to the Spin-Off from the Former Parent on October 3, 2022, Biohaven did not operate as an independent company. At the time of the Distribution, 39,375,944 common shares of the Company were distributed to the Former Parent's shareholders, including common shares issued in connection with Former Parent share options that were exercised on October 3, 2022 and common shares issued in connection with Former Parent restricted share units that vested on October 3, 2022. This number of shares is being utilized for the calculation of basic and diluted earnings per share for all periods presented prior to the Spin-Off. The Company's potential dilutive securities include share options which have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common shareholders of the Company is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common shareholders for the periods indicated because including them would have had an anti-dilutive effect: As of September 30, 2023 Options to purchase common shares 9,740,921

License Agreements

License Agreements	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License Agreements	License Agreements The following is a summary of all license agreements that the Company has entered into. As of September 30, 2023, the Company has potential future developmental, regulatory and commercial milestone payments under these agreements of up to approximately $123,800, $547,350, and $1,270,450, respectively. As of September 30, 2023 the Company has made $1,325 of payments related to achievement of developmental milestones under these agreements. The Company has not made any material regulatory or commercial milestone payments under these agreements. Yale Agreements In September 2013, the Company entered into an exclusive license agreement (the "Yale Agreement") with Yale University to obtain a license to certain patent rights for the commercial development, manufacture, distribution, use and sale of products and processes resulting from the development of those patent rights, related to the use of riluzole in treating various neurological conditions, such as general anxiety disorder, post-traumatic stress disorder and depression. The Yale Agreement was amended and restated in May 2019. As amended, the Company agreed to pay Yale University up to $2,000 upon the achievement of specified regulatory milestones and annual royalty payments of a low single-digit percentage based on net sales of riluzole-based products from the licensed patents or from products based on troriluzole. Under the amended and restated agreement, the royalty rates are reduced as compared to the original agreement. In addition, under the amended and restated agreement, the Company may develop products based on riluzole or troriluzole. The amended and restated agreement retains a minimum annual royalty of up to $1,000 per year, beginning after the first sale of product under the agreement. If the Company grants any sublicense rights under the Yale Agreement, it must pay Yale University a low single-digit percentage of sublicense income that it receives. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments under the Yale Agreement. In January 2021, the Company entered into a worldwide, exclusive license agreement with Yale University for the development and commercialization of a novel Molecular Degrader of Extracellular Protein ("MoDE") platform (the "Yale MoDE Agreement"). Under the Yale MoDE Agreement, the Company acquired exclusive, worldwide rights to Yale University's intellectual property directed to its MoDE platform. The platform pertains to the clearance of disease-causing protein and other biomolecules by targeting them for lysosomal degradation using multi-functional molecules. As part of consideration for this license, the Company paid Yale University an upfront cash payment of $1,000 and 11,668 common shares of the Former Parent valued at approximately $1,000. Under the Yale MoDE Agreement, the Company may develop products based on the MoDE platform. The Yale MoDE Agreement includes an obligation to pay a minimum annual royalty of up to $1,000 per year, and low single digit royalties on the net sales of licensed products. If the Company grants any sublicense rights under the Yale MoDE Agreement, it must pay Yale University a low single-digit percentage of sublicense income that it receives. In addition, Yale University will be eligible to receive additional development milestone payments of up to $800 and commercial milestone payments of up to $2,950. The Yale MoDE Agreement terminates on the later of twenty years from the effective date, twenty years from the filing date of the first investigational new drug application for a licensed product or the last to expire of a licensed patent. Under the Yale MoDE Agreement, the Company entered into a sponsored research agreement (the “Yale MoDE SRA”), which includes funding of up to $4,000 over the life of the agreement. The Company recorded research and development expense related to the Yale MoDE SRA of $333 and $1,000 for the three and nine months ended September 30, 2023. For the three and nine months ended September 30, 2022, the Company recorded research and development expense related to the Yale MoDE SRA of $333 and $2,333, respectively. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments under the Yale MoDE SRA. In May 2023, the Company entered into an additional sponsored research agreement with Yale University (the "2023 Yale SRA"), which included funding of up to $612 over the life of the agreement. For the three and nine months ended September 30, 2023, the Company recorded $92 and 245, respectively, in research and development expense related to the 2023 Yale SRA. ALS Biopharma Agreement In August 2015, the Company entered into an agreement (the "ALS Biopharma Agreement") with ALS Biopharma and Fox Chase Chemical Diversity Center Inc. ("FCCDC"), pursuant to which ALS Biopharma and FCCDC assigned the Company their worldwide patent rights to a family of over 300 prodrugs of glutamate modulating agents, including troriluzole, as well as other innovative technologies. Under the ALS Biopharma Agreement, the Company is obligated to use commercially reasonable efforts to commercialize and develop markets for the patent products. The Company is obligated to pay $3,000 upon the achievement of specified regulatory milestones with respect to the first licensed product and $1,000 upon the achievement of specified regulatory milestones with respect to subsequently developed products, as well as royalty payments of a low single-digit percentage based on net sales of products licensed under the ALS Biopharma Agreement, payable on a quarterly basis. The ALS Biopharma Agreement terminates on a country-by-country basis as the last patent rights expire in each such country. If the Company abandons its development, research, licensing or sale of all products covered by one or more claims of any patent or patent application assigned under the ALS Biopharma Agreement, or if the Company ceases operations, it has agreed to reassign the applicable patent rights back to ALS Biopharma. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments under the ALS Biopharma Agreement. 2016 AstraZeneca Agreement In October 2016, the Company entered into an exclusive license agreement (the "2016 AstraZeneca Agreement") with AstraZeneca, pursuant to which AstraZeneca granted the Company a license to certain patent rights for the commercial development, manufacture, distribution and use of any products or processes resulting from development of those patent rights, including BHV-5000 and BHV-5500. In exchange for these rights, the Company agreed to pay AstraZeneca an upfront payment, milestone payments and royalties on net sales of licensed products under the agreement. The regulatory milestones due under the 2016 AstraZeneca Agreement depend on the indication of the licensed product being developed as well as the territory where regulatory approval is obtained. Regulatory milestones due under the 2016 AstraZeneca Agreement with respect to Rett syndrome total up to $30,000, and, for any indication other than Rett syndrome, total up to $60,000. Commercial milestones are based on net sales of all products licensed under the 2016 AstraZeneca Agreement and total up to $120,000. The Company has also agreed t o pay royalties in two tiers, with each tiered royalty in the range from 0-10% of net sales of products licensed under the 2016 AstraZeneca Agreement. If the Company receives revenue from sublicensing any of its rights under the 2016 AstraZeneca Agreement, the Company is also obligated to pay a portion of that revenue to AstraZeneca. The Company is also required to reimburse AstraZeneca for any fees that AstraZeneca incurs related to the filing, prosecution, defending, and maintenance of patent rights licensed under the 2016 AstraZeneca Agreement. The 2016 AstraZeneca Agreement expires upon the expiration of the patent rights under the agreement or on a country-by-country basis ten years after the first commercial sale and can also be terminated if certain events occur, e.g., material breach or insolvency. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments under the 2016 AstraZeneca Agreement. 2018 AstraZeneca License Agreement In September 2018, the Company entered into an exclusive license agreement (the "2018 AstraZeneca Agreement") with AstraZeneca, pursuant to which AstraZeneca granted the Company a license to certain patent rights for the commercial development, manufacture, distribution and use of any products or processes resulting from development of those patent rights, including BHV-3241 (verdiperstat). Under the 2018 AstraZeneca Agreement, the Company paid AstraZeneca an upfront cash payment of $3,000 and 109,523 shares valued at $4,080 on the date of settlement and is obligated to pay milestone payments to AstraZeneca totaling up to $55,000 upon the achievement of specified regulatory and commercial milestones and up to $50,000 upon the achievement of specified sales-based milestones. In addition, the Company will pay AstraZeneca royalties in three tiers, with each tiered royalty in the range from 0-10% of net sales of specified approved products, subject to specified reductions. In November 2021, the Company completed enrollment in a Phase 3 clinical trial of this product candidate, which is now referred to as verdiperstat, for the treatment of Amyotrophic Lateral Sclerosis ("ALS").In September 2022, the Company announced negative topline results from the Phase 3 clinical trial of verdiperstat for ALS. ALS is a progressive, life-threatening, and rare neuromuscular disease for which there are currently limited treatment options and no cure. The Company is solely responsible, and has agreed to use commercially reasonable efforts, for all development, regulatory and commercial activities related to verdiperstat. The Company may sublicense its rights under the agreement and, if it does so, will be obligated to pay a portion of any milestone payments received from the sublicense to AstraZeneca in addition to any milestone payments it would otherwise be obligated to pay. The 2018 AstraZeneca Agreement terminates on a country-by-country basis and product-by-product basis upon the expiration of the royalty term for such product in such country and can also be terminated if certain events occur, e.g., material breach or insolvency. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments under the 2018 AstraZeneca Agreement. Fox Chase Chemical Diversity Center Inc. Agreement In May 2019, the Company entered into an agreement with FCCDC (the "FCCDC Agreement") pursuant to which the Company purchased certain intellectual property relating to the TDP-43 protein from FCCDC. The FCCDC Agreement provides the Company with a plan and goal to identify one or more new chemical entity candidates for preclinical development for eventual clinical evaluation for the treatment of one or more TDP-43 proteinopathies. As consideration, the Company issued 100,000 of the Former Parent's common shares to FCCDC valued at $5,646. In addition, the Company is obligated to pay FCCDC milestone payments totaling up to $3,000 with $1,000 for each additional NDA filing. The Company also issued a warrant to FCCDC, granting FCCDC the option to purchase up to 100,000 of the Former Parent’s common shares, at a strike price of $56.46 per share, subject to vesting upon achievement of certain milestones in development of TDP-43. In connection with the Separation, the warrants issued to FCCDC were vested and settled, resulting in $4,245 being recorded as research and development expense in the fourth quarter of 2022. In connection with the FCCDC Agreement, the Company and FCCDC have established a TDP-43 Research Plan, which was amended in November 2020, under which the Company will pay FCCDC an earned royalty equal to 0% to 10% of net sales of any TD-43 patent products with a valid claim as defined in the FCCDC Agreement. The Company may also license the rights developed under the FCCDC Agreement and, if it does so, will be obligated to pay a portion of any payments received from such licensee to FCCDC in addition to any milestones it would otherwise be obligated to pay. The Company is also responsible for the prosecution and maintenance of the patents related to the TDP-43 assets. The FCCDC Agreement terminates on a country-by-country basis and product-by-product basis upon expiration of the royalty term for such product in such country and can also be terminated if certain events occur, e.g., material breach or insolvency. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments related to the FCCDC Agreement. UConn In October 2018, the Company announced it had signed an exclusive, worldwide option and license agreement (the “UConn Agreement”) with the University of Connecticut (“UConn”) for the development and commercialization rights to UC1MT, a therapeutic antibody targeting extracellular metallothionein. Under the UConn Agreement, the Company had the option to acquire an exclusive, worldwide license to UC1MT and its underlying patents to develop and commercialize throughout the world in all human indications (the "UConn Option"). In September 2022, the Company exercised the UConn Option in exchange for a payment of $400. Under the UConn Agreement, UConn is entitled to milestone payments upon the achievement of specified developmental and regulatory milestones of up to $30,100 and commercial milestones of up to $50,000, and royalties of a low single-digit percentage of net sales of licensed products. Other than the payment made in connection with the exercise of the UConn Option in September 2022, for the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments related to the UConn Agreement. Artizan Agreement In December 2020, the Company entered into an Option and License Agreement (the "2020 Artizan Agreement") with Artizan Biosciences Inc. ("Artizan"). Pursuant to the 2020 Artizan Agreement, the Company acquired an option (“Biohaven Option”) to obtain a royalty-based license from Artizan to manufacture, use and commercialize certain products in the United States for the treatment of diseases, including, for example, inflammatory bowel disease and other gastrointestinal inflammatory disorders, e.g., Crohn’s disease. The Biohaven Option is exercisable throughout the development phase of the products at an exercise price of approximately $4,000 to $8,000, which varies based on the market potential of the products. In June 2023, the Company agreed to terminate the 2020 Artizan Agreement and relinquished its option rights under certain conditions associated with the winding down of Artizan's business. In December 2020, simultaneously with the 2020 Artizan Agreement, the Company entered into a Series A-2 Preferred Stock Purchase Agreement with Artizan. Under the agreement, the Company paid Artizan 61,494 of the Former Parent’s common shares valued at $6,000, which were issued in January 2021. In exchange, the Company acquired 34,472,031 shares of series A-2 preferred stock of Artizan. In June 2021, the Company entered into a Development and License Agreement with Artizan Biosciences Inc (the "2021 Artizan Agreement"). Pursuant to the 2021 Artizan Agreement, the Company acquired an exclusive, worldwide license under Artizan’s IgA-SEQ patented technology and know-how to develop, manufacture and commercialize certain of Artizan’s compounds for use in Parkinson’s Disease. Under the 2021 Artizan Agreement, the Company is responsible for funding the development of the compounds, obtaining regulatory approvals, manufacturing the compounds and commercializing the compounds. The Company is also responsible for the prosecution, maintenance and enforcement of Artizan’s patents. The Company agreed to pay Artizan development milestones of $20,000 for the first licensed compound to achieve U.S. marketing authorization and $10,000 for each subsequent U.S. approval. In addition, the Company agreed to pay Artizan commercialization milestones totaling up to $150,000 and royalties in the low- to mid-single digits. The 2021 Artizan Agreement terminates on a country-by-country basis on the later of 10 years from the first commercial sale of licensed product in such country or the expiration of Artizan’s patents in such country and can also be terminated if certain events occur, e.g., material breach or insolvency. In June 2023, the 2021 Artizan Agreement was terminated. In June 2022, the Company entered into an amendment (the "Amendment") to the Series A-2 Preferred Stock Purchase Agreement with Artizan. Under the Amendment, the Company made a cash payment of $4,000 in exchange for 22,975,301 shares of series A-2 preferred stock of Artizan out of a total of 45,950,601 shares of series A-2 preferred stock of Artizan for a total raise of $8,000 (the “A2 Extension Raise”). Along with the Amendment, the Company and Artizan executed a non-binding indication of interest (“Artizan Side Letter”), which describes terms under which the Company and Artizan would amend the 2020 Artizan Agreement to eliminate certain milestone payments required by us in exchange for limiting our option to the selection of the first licensed product. The Artizan Side Letter required Artizan to commit at least 80% of the funds raised in the A-2 Extension Raise to a certain program and to raise $35,000 of additional capital within a certain time. As of December 31, 2022, due to concerns related to Artizan's inability to fund its future operations, the Company determined its investment in Artizan to be fully impaired. Accordingly, during the fourth quarter of 2022, the Company recognized an impairment loss of $10,000 in other income (expense) on the consolidated statements of operations. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments related to the 2020 Artizan Agreement and the 2021 Artizan Agreement. Reliant Agreement In July 2021, the Company entered into a development and licensing agreement (the "Reliant Agreement") with Reliant Glycosciences LLC ("Reliant"), pursuant to which the Company and Reliant have agreed to collaborate on a program with Biohaven Labs’ multifunctional molecules to develop and commercialize conjugated antibodies for therapeutic uses relating to IgA nephropathy and treatment of other diseases and conditions. Under the Reliant Agreement, the Company paid Reliant an upfront payment in the form of issuance of common shares of the Former Parent valued at approximately $3,686, which the Company recorded as research and development expense on its condensed consolidated statement of operations and comprehensive loss. In addition, Reliant will be eligible to receive development and regulatory milestone payments of up to $36,500, and royalties of a low single-digit percentage of net sales of licensed products. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments related to the Reliant Agreement. KU Leuven Agreement In January 2022, the Company and Katholieke Universiteit Leuven ("KU Leuven") entered into an Exclusive License and Research Collaboration Agreement (the "KU Leuven Agreement") to develop and commercialize TRPM3 antagonists to address the growing proportion of people worldwide living with chronic pain disorders. The TRPM3 antagonist platform was discovered at the Centre for Drug Design and Discovery and the Laboratory of Ion Channel Research at KU Leuven. Under the KU Leuven Agreement, the Company receives exclusive global rights to develop, manufacture and commercialize KU Leuven's portfolio of small-molecule TRPM3 antagonists. The portfolio includes the lead candidate, henceforth known as BHV-2100, which is being evaluated in preclinical pain models and will be the first to advance towards Phase 1 studies. The Company will support further basic and translational research at KU Leuven on the role of TRPM3 in pain and other disorders. As consideration, KU Leuven received an upfront cash payment of $3,000 and 15,340 shares of the Former Parent valued at $1,779, and is eligible to receive additional development, regulatory, and commercialization milestones payments of up to $327,750. In addition, KU Leuven will be eligible to receive mid-single digit royalties on net sales of products resulting from the collaboration. For the three and nine months ended September 30, 2023, the Company recorded $1,250 to R&D expense in the condensed consolidated statements of operations and comprehensive loss related to a developmental milestone, which became due to KU Leuven during the third quarter of 2023. For the three and nine months ended September 30, 2022, the Company did not record any material milestone or royalty payments related to the KU Leuven Agreement. In November 2023, the Company recorded $2,000 to R&D expense related to a developmental milestone which became due to KU Leuven and is expected to be paid during the fourth quarter of 2023. Taldefgrobep Alfa License Agreement In February 2022, following the transfer of intellectual property, the Company announced that it entered into a worldwide license agreement with BMS for the development and commercialization rights to taldefgrobep alfa (also known as BMS-986089), a novel, Phase 3-ready anti-myostatin adnectin (the "Taldefgrobep Alfa License Agreement"). Under the terms of the Taldefgrobep Alfa License Agreement, the Company received worldwide rights to taldefgrobep alfa and BMS will be eligible for regulatory approval milestone payments of up to $200,000, as well as tiered, sales-based royalty percentages from the high teens to the low twenties. There were no upfront or contingent payments to BMS related to the Taldefgrobep Alfa License Agreement. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments under the Taldefgrobep Alfa License Agreement. Agreement with Hangzhou Highlightll Pharmaceutical Co. Ltd. In March 2023, the Company and Hangzhou Highlightll Pharmaceutical Co. Ltd. ("Highlightll") entered into an exclusive, worldwide (excluding People’s Republic of China and its territories and possessions) license agreement (the "Highlightll Agreement") pursuant to which Biohaven obtained the right to research, develop, manufacture and commercialize Highlightll’s brain penetrant dual TYK2/JAK1 inhibitor program. As partial consideration for the Highlightll Agreement, the Company is obligated to pay Highlightll a cash payment of $10,000 and 721,136 common shares valued at approximately $10,000 as of the date the Highlightll Agreement was executed, upon the completion of certain post-closing activities, which were not completed as of September 30, 2023. Under the Highlightll Agreement, the Company is obligated to make milestone payments to Highlightll totaling up to $200,000 upon the achievement of specified developmental, regulatory and commercial milestones for a first indication, up to $100,000 upon the achievement of pre-specified developmental, regulatory and commercial milestones for a second indication, and up to $650,000 upon the achievement of specified sales-based milestones. Additionally, the Company has agreed to make tiered royalty payments as a percentage of net sales starting at mid single digits and peaking at low teens digits. During the royalty term, if the Company offers to include China clinical sites in its Phase 3 study sufficient for submission to Chinese National Medical Products Administration and Highlightll, at its sole discretion, agrees, then Highlightll will pay royalties in the low tens digits to the Company on China sales upon approval. The Highlightll Agreement terminates on a country-by-country basis upon expiration of the royalty term and can also be terminated if certain events occur, e.g., material breach or insolvency. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone or royalty payments related to the Highlightll Agreement.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Agreements The Company leases certain office and laboratory space. There have been no material changes to the lease obligations from those disclosed in Note 12, "Commitments and Contingencies" to the consolidated financial statements included in the 2022 Form 10-K. Research Commitments The Company has agreements with several contract manufacturing organizations ("CMOs") and contract research organizations ("CROs") to provide products and services in connection with the Company’s preclinical studies and clinical trials. As of September 30, 2023, the Company had remaining maximum research commitments in excess of one year of approximately $11,475, which are variable based on the number of trial participants, and contingent upon the achievement of certain milestones of the clinical trials covered under the agreements. If all related milestones are achieved, the Company expects these amounts to be paid over the next two years. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. The Company’s amended and restated memorandum and articles of association also provide for indemnification of directors and officers in specific circumstances. To date, the Company has not incurred any material costs as a result of such indemnification provisions. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of September 30, 2023 or December 31, 2022. License Agreements The Company entered into license agreements with various parties under which it is obligated to make contingent and non-contingent payments (see Note 10). Other Agreements Moda Agreement On January 1, 2021, the Company entered into a consulting services agreement (the "Moda Agreement") with Moda Pharmaceuticals LLC ("Moda") to further the scientific advancement of technology, drug discovery platforms (including the technology licensed under the Yale MoDE Agreement), product candidates and related intellectual property owned or controlled by the Company. Under the Moda Agreement, the Company paid Moda an upfront cash payment of $2,700 and 37,836 shares of the Former Parent valued at approximately $3,243. In addition, Moda will be eligible to receive additional development milestone payments of up to $81,612 and commercial milestone payments of up to $30,171. The Moda Agreement has a term of four years and may be terminated earlier by the Company or Moda under certain circumstances including, for example, the Company's discontinuation of research on the MoDE platform or default. For the three and nine months ended September 30, 2023 and 2022, the Company did not record any material milestone payments related to the Moda Agreement. Legal Proceedings

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesThe following table provides a comparative summary of the Company's income tax (benefit) provision and effective income tax rate for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Income tax (benefit) provision $ (3,287) $ 1,216 $ (171) $ 14,581 Effective income tax rate (3.1) % 1.8 % (0.1) % 4.1 % The decrease in income tax provision for the three and nine months ended September 30, 2023 as compared to 2022 was primarily attributable to the Company adopting the guidance contained in a Notice of Proposed Rule Making issued during the third quarter of 2023 by the United States Internal Revenue Service ("the Notice"). The Notice provides clarity regarding the Company’s ability to immediately deduct certain R&D expenditures which were incurred in the US and reimbursed by the Company’s foreign parent. Previously these expenditures were capitalized, as was generally required under the Tax Cuts and Jobs Act, which was effective for tax years beginning on or after January 1, 2022. Based on this additional guidance and its application to the Company’s specific facts, the Company deducted these expenditures on its 2022 tax return, substantially reducing the Company's taxable income in the US and capitalized R&D expenditures, resulting in an increase to the Company's federal net operating loss carryforward of $598,679 that can be carried forward indefinitely. At September 30, 2023 and December 31, 2022, the Company continued to maintain a full valuation allowance against its net deferred tax assets, comprised primarily of research and development tax credit carryforwards and net operating loss carryforwards, based on management’s assessment that it is more likely than not that the deferred tax assets will not be realized.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Relationship with the Former Parent Upon the effectiveness of the Separation on October 3, 2022, the Former Parent ceased to be a related party of the Company. On October 3, 2022, the Company entered into agreements with the Former Parent in connection with the Separation, including the following: Transition Services Agreement. The Company entered into a Transition Services Agreement with the Former Parent (the “Transition Services Agreement”) under which the Company or one of its affiliates provides the Former Parent, and the Former Parent or one of its affiliates provides the Company, with certain transition services for a limited time to ensure an orderly transition following the Spin-Off. The services that the Company and the Former Parent agreed to provide to each other under the Transition Services Agreement include certain finance, information technology, clinical study support, human resources and compensation, facilities, financial reporting and accounting and other services. The Company pays the Former Parent, and the Former Parent pays the Company, for any such services received by the Former Parent or the Company, as applicable, at agreed amounts as set forth in the Transition Services Agreement. Amounts received in connection with the Transition Services Agreement are recorded as other income on the condensed consolidated statement of operations and comprehensive loss, as they are outside of the normal operating business of the Company. For the three and nine months ended September 30, 2023, the Company recorded $1,233 and $6,753 in other income reflecting transition services provided to the Former Parent. As of September 30, 2023, the Company had a receivable of $1,840 included in other current assets on the condensed consolidated balance sheet relating to transition services provided to the Former Parent. United States Distribution Services Agreement. The Company entered into a United States Distribution Services Agreement with the Former Parent, pursuant to which the Company continued to serve as the Former Parent’s distributor and agent for the distribution of the pharmaceutical product Nurtec ODT in the United States for a limited period of time following the Spin-Off, which has concluded. Under the Distribution Services Agreement, the Former Parent and Pfizer Inc. have agreed to indemnify the Company for, among other things, losses resulting from the conduct of the distribution business or actions taken at the direction of the Former Parent. As the Company was acting as an agent of the Former Parent for services performed under the Distribution Services Agreement, no amounts for revenues or expenses relating to the services performed thereunder are included on the Company's condensed consolidated financial statements. As of September 30, 2023, the Company recorded restricted cash held on behalf of Former Parent of $28 and Due to Former Parent of $28 on the condensed consolidated balance sheet primarily relating to cash held in connection with the execution of the Distribution Services Agreement which is legally payable to the Former Parent. Outsourcing & Employee Transfer Agreements. The Company entered into Outsourcing & Employee Transfer Agreements, one with Pfizer Inc., Merger Sub, the Former Parent and Biohaven Pharmaceuticals, Inc. (“U.S. Employer”), and the other with Pfizer, Merger Sub, the Former Parent, and BioShin (Shanghai) Consulting Services Co., Ltd. (“Chinese Employer”), pursuant to which the Chinese Employer and the U.S. Employer, among other things, provided Pfizer with the services of, and remained the employers of, certain of their employees for the period of time immediately following the Spin-Off through December 31, 2022. During such period, Pfizer or one of its affiliates paid the U.S. Employer for employee-related expenses for its employees (including the cost of salary and wages) and paid the Chinese Employer a service fee based on employee-related expenses for its employees (including the cost of salary and wages). Amounts received in connection with the Outsourcing & Employee Transfer Agreements are recorded against their related operating expenses as they represent reimbursements for operating expenses incurred by the Company on behalf of the Former Parent. Relationship with the Former Parent prior to the Separation Pursuant to the Distribution Agreement, immediately prior to the Separation the Former Parent made a cash contribution to the Company which resulted in a cash balance of approximately $257,799 as of October 3, 2022. Prior to the Separation, the Company did not historically operate as a standalone business and the condensed consolidated financial statements were derived from the consolidated financial statements and accounting records of the Former Parent. The following disclosure summarizes activity between the Company and the Former Parent prior to the Separation, including the affiliates of the Former Parent that were not part of the Spin-Off. Cost Allocations The condensed consolidated financial statements for periods prior to the Separation reflect allocations of certain expenses from the financial statements of the Former Parent, including research and development expenses and general and administrative expenses. These allocations include, but are not limited to, executive management, employee compensation and benefits, facilities and operations, information technology, business development, financial services (such as accounting, audit, and tax), legal, insurance, and non-cash share-based compensation. For periods prior to the Separation, these allocations to the Company are reflected in the condensed consolidated statement of operations and comprehensive loss as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 Research and development $ 23,048 $ 84,772 General and administrative 9,676 43,053 Total $ 32,724 $ 127,825 Management believes these cost allocations are a reasonable reflection of services provided to, or the benefit derived by, the Company during the period presented. The allocations may not, however, be indicative of the actual expenses that would have been incurred had the Company operated as a standalone public company. Actual costs that may have been incurred if the Company had been a standalone public company would depend on a number of factors, including the chosen organizational structure, what corporate functions the Company might have performed directly or outsourced and strategic decisions the Company might have made in areas such as executive management, legal and other professional services, and certain corporate overhead functions. Non-Cash Share-Based Compensation Prior to the Separation, Biohaven employees participated in the Former Parent’s non-cash share-based compensation plans, the costs of which have been allocated to the Company and recorded in research and development and general and administrative expenses in the condensed consolidated statements of operations and comprehensive loss. Net Transfers From Former Parent Net transfers from Former Parent represent the net effect of transactions between the Company and the Former Parent prior to the Separation. The components of net transfers from Former Parent are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 General financing activities $ 111,816 $ 187,519 Corporate cost allocations, excluding share-based compensation 15,727 49,898 Net transfers from Former Parent as reflected in the Condensed Consolidated Statement of Cash Flows 127,543 237,417 Share-based compensation 16,997 77,927 Issuance of Former Parent common shares to repurchase non-controlling interest in a subsidiary — 60,000 Issuance of Former Parent common shares as payment for IPR&D asset acquisition — 58,747 Issuance of Former Parent common shares as payment for license and consulting agreements — 1,779 Other non-cash adjustments (469) (1,173) Net transfers from Former Parent as reflected in Note 7, "Shareholders' Equity" $ 144,071 $ 434,697 Related Party Agreements License Agreement with Yale University On September 30, 2013, the Company entered into the Yale Agreement with Yale University (see Note 10). The Company’s Chief Executive Officer is one of the inventors of the patents that the Company has licensed from Yale University and, as such, is entitled to a specified share of the glutamate product-related royalty revenues that may be received by Yale University under the Yale Agreement. In January 2021, the Company entered into the Yale MoDE Agreement with Yale University (see Note 10 for details). Under the license agreement, the Company acquired exclusive, worldwide rights to Yale University's intellectual property directed to its MoDE platform. As part of consideration for this license, the Company paid Yale University an upfront cash payment of $1,000 and 11,668 common shares of the Former Parent valued at approximately $1,000. Under the Yale MoDE Agreement, the Company entered into the Yale MoDE SRA (see Note 10 for details), which included funding of up to $4,000 over the life of the agreement. In May 2023, the Company entered into an additional sponsored research agreement with Yale University (the "2023 Yale SRA"), which includes funding of up to $612 over the life of the agreement. For the three and nine months ended September 30, 2023, the Company recorded $614 and $2,313, respectively, in research and development expense, including certain administrative expenses, related to the Yale MoDE Agreement and the Yale MoDE SRA, the Yale Agreement, and the 2023 Yale SRA (the "Yale Agreements"). For the three and nine months ended September 30, 2022, the Company recorded $463 and $2,750, respectively, in research and development expense, including certain administrative expenses, related to the Yale Agreements. As of September 30, 2023, the Company did not owe any amounts to Yale University.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Unaudited Interim Condensed Consolidated Financial Information	Unaudited Interim Condensed Consolidated Financial InformationThe accompanying unaudited condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information. The accompanying unaudited condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. The accompanying year-end condensed consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2023, the results of its operations for the three and nine months ended September 30, 2023 and 2022, and its cash flows for the nine months ended September 30, 2023 and 2022. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods or any future year or period.  The financial information included herein should be read in conjunction with the financial statements and notes in the Company's Annual Report on Form 10-K for the year ended December 31, 2022
Reclassifications	Reclassifications Certain items in the prior period’s condensed consolidated financial statements have been reclassified to conform to the current year presentation.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of income and expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, determining the allocations of costs and expenses from the Former Parent and the accrual for research and development expenses. In addition, management’s assessment of the Company’s ability to continue as a going concern involves the estimation of the amount and timing of future cash inflows and outflows. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates.
Restricted Cash	Restricted cash held on behalf of the Former Parent on the consolidated balance sheet as of September 30, 2023 represents cash held by the Company on behalf of the Former Parent related to the execution of the United States Distribution Services Agreement (the “Distribution Services Agreement”). Pursuant to the terms of the Distribution Services Agreement, which was entered into by the Company and the Former Parent in connection with the Separation, the Company is continuing to serve as the Former Parent’s distributor and agent for the distribution of the pharmaceutical product Nurtec ODT in the United States. As of September 30, 2023, the Company recorded a related payable of $28 as Due to Former Parent on the consolidated balance sheet as the balance was legally payable to the Former Parent. Refer to Note 13, "Related Party Transactions" for further information on the agreements entered into by the Company and the Former Parent in connection with the Separation. Restricted cash included in other current assets as of September 30, 2023 consisted primarily of restricted cash held in escrow for the cash portion of consideration to be paid in connection with our license agreement with Hangzhou Highlightll Pharmaceutical Co. Ltd. ("Highlightll") upon the completion of certain post-closing activities, which were not completed as of September 30, 2023. Restricted cash included in other current assets also includes employee contributions to
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2022, the FASB issued ASU No. 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions, to clarify the guidance in Topic 820 when measuring the fair value of an equity security subject to contractual restrictions that prohibit the sale of an equity security. The ASU also introduced new disclosure requirements for equity securities subject to contractual sale restrictions that are measured at fair value in accordance with Topic 820. The amendments in ASU 2022-03 are effective for fiscal years beginning after December 15, 2023. The Company does not expect ASU No. 2022-03 to have a material effect on its consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Schedule of reconciliation of total cash, cash equivalents and restricted cash	The following represents a reconciliation of cash and cash equivalents in the condensed consolidated balance sheets to total cash, cash equivalents and restricted cash as of September 30, 2023 and September 30, 2022, respectively, in the condensed consolidated statements of cash flows: As of September 30, 2023 As of September 30, 2022 Cash and cash equivalents $ 111,697 $ 50,668 Restricted cash held on behalf of Former Parent 28 — Restricted cash (included in other current assets) 11,890 — Restricted cash (included in other non-current assets) 2,375 750 Total cash, cash equivalents and restricted cash at the end of the period in the condensed consolidated statement of cash flows $ 125,990 $ 51,418

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Schedule of reconciliation of available-for-sale debt securities from amortized cost to fair value	The amortized cost, gross unrealized holding gains, gross unrealized holding losses and fair value of debt securities available-for-sale by type of security at September 30, 2023 and December 31, 2022 were as follows: Amortized Cost Allowance for Credit Losses Net Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2023 Debt securities U.S. corporate bonds $ 64,635 $ — $ 64,635 $ — $ (62) $ 64,573 Foreign corporate bonds 24,623 — 24,623 — (19) 24,604 U.S. treasury bills 39,759 — 39,759 3 — 39,762 U.S. agency bonds 4,965 — 4,965 — (5) 4,960 Total $ 133,982 $ — $ 133,982 $ 3 $ (86) $ 133,899 December 31, 2022 Debt securities U.S. corporate bonds $ 142,697 $ — $ 142,697 $ 25 $ (135) $ 142,587 Foreign corporate bonds 36,766 — 36,766 9 (32) 36,743 U.S. treasury bills 89,308 — 89,308 17 (5) 89,320 U.S. agency bonds 41,734 — 41,734 — (24) 41,710 Total $ 310,505 $ — $ 310,505 $ 51 $ (196) $ 310,360 The fair value of debt securities available-for-sale by classification in the condensed consolidated balance sheets was as follows: September 30, 2023 December 31, 2022 Cash and cash equivalents $ 5,000 $ 49,896 Marketable securities 128,899 260,464 Total $ 133,899 $ 310,360
Schedule of available-for-sale debt securities by contractual maturity	The net amortized cost and fair value of debt securities available-for-sale at September 30, 2023 and December 31, 2022 are shown below by contractual maturity. Actual maturities may differ from contractual maturities because securities may be restructured, called or prepaid, or the Company intends to sell a security prior to maturity. September 30, 2023 December 31, 2022 Net Amortized Cost Fair Value Net Amortized Cost Fair Value Due to mature: Less than one year $ 133,982 $ 133,899 $ 310,505 $ 310,360
Summary of debt securities available-for-sale in an unrealized loss position, aggregated by the length of time	Summarized below are the debt securities available-for-sale the Company held at September 30, 2023 and December 31, 2022 that were in an unrealized loss position, aggregated by the length of time the investments have been in that position: Less than 12 months Number of Securities Fair Value Unrealized Losses September 30, 2023 Debt securities U.S. corporate bonds 11 $ 64,573 $ (62) Foreign corporate bonds 3 24,604 (19) U.S. treasury bills 2 9,882 — U.S. agency bonds 1 4,960 (5) Total 17 $ 104,019 $ (86) December 31, 2022 Debt securities U.S. corporate bonds 16 $ 104,508 $ (135) Foreign corporate bonds 3 31,886 (32) U.S. treasury bills 1 9,762 (5) U.S. agency bonds 4 41,710 (24) Total 24 $ 187,866 $ (196)
Schedule of net investment income	Sources of net investment income included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2023 Gross investment income $ 3,831 $ 12,231 Investment expenses (65) (203) Net investment income (excluding net realized capital losses) 3,766 12,028 Net realized capital losses — (39) Net investment income $ 3,766 $ 11,989
Schedule of proceeds from sale of available-for-sale debt securities and related gross realized capital gains and losses	The proceeds from the sale of available-for-sale debt securities and the related gross realized capital losses for the three and nine months ended September 30, 2023 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2023 Proceeds from sales $ — $ 4,920 Gross realized capital losses — $ 39

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities measured at fair value on a recurring basis	Financial assets measured at fair value on a recurring basis on the condensed consolidated balance sheets at September 30, 2023 and December 31, 2022 were as follows: Fair Value Measurement Using: Balance Sheet Classification Type of Instrument Level 1 Level 2 Level 3 Total September 30, 2023 Assets: Cash and cash equivalents Money market funds $ 29,794 $ — $ — $ 29,794 Cash and cash equivalents U.S. treasury bills — 5,000 — 5,000 Marketable securities U.S. treasury bills 9,920 24,842 — 34,762 Marketable securities U.S. corporate bonds — 64,573 — 64,573 Marketable securities U.S. agency bonds — 4,960 — 4,960 Marketable securities Foreign corporate bonds — 24,604 — 24,604 Other non-current assets Money market funds 1,875 — — 1,875 Total assets $ 41,589 $ 123,979 $ — $ 165,568 December 31, 2022 Assets: Cash and cash equivalents Money market funds $ 72,866 $ — $ — $ 72,866 Cash and cash equivalents U.S. treasury bills — 39,948 — 39,948 Cash and cash equivalents U.S. corporate bonds — 9,948 — 9,948 Marketable securities U.S. treasury bills — 49,372 — 49,372 Marketable securities U.S. corporate bonds — 132,639 — 132,639 Marketable securities U.S. agency bonds — 41,710 — 41,710 Marketable securities Foreign corporate bonds — 36,743 — 36,743 Total assets $ 72,866 $ 310,360 $ — $ 383,226

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of property and equipment, net	Property and equipment, net consisted of the following: As of September 30, 2023 As of December 31, 2022 Building and land $ 11,728 $ 11,728 Leasehold improvements 680 569 Computer hardware and software 780 780 Office and lab equipment 9,148 5,501 Furniture and fixtures 1,491 1,202 $ 23,827 $ 19,780 Accumulated depreciation (7,335) (4,914) 16,492 14,866 Equipment not yet in service 1,177 2,646 Property and equipment, net $ 17,669 $ 17,512
Schedule of other noncurrent assets	Other non-current assets consisted of the following: As of September 30, 2023 As of December 31, 2022 Operating lease right-of-use assets $ 32,330 $ 34,928 Other 2,377 2,585 Other non-current assets $ 34,707 $ 37,513
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following: As of September 30, 2023 As of December 31, 2022 Accrued employee compensation and benefits $ 13,977 $ 14,603 Accrued clinical trial costs 27,945 17,788 Operating lease liability - current portion 3,281 3,019 Other accrued expenses and other current liabilities 7,431 8,696 Accrued expenses and other current liabilities $ 52,634 $ 44,106

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Stockholders' Equity Note [Abstract]
Schedule of changes in shareholders' equity (deficit)	Changes in shareholders’ equity for the three and nine months ended September 30, 2023 and September 30, 2022 were as follows: Common Shares Shares Amount Net Investment from Former Parent Additional Paid-in Capital Accumulated Deficit Accumulated Other Comprehensive Income Total Shareholders' Equity Balances as of December 31, 2022 68,190,479 $ 615,742 $ — $ 13,869 $ (91,124) $ 284 $ 538,771 Issuance of common shares under equity incentive plan 22,000 504 — (172) — — 332 Non-cash share-based compensation expense — — — 3,765 — — 3,765 Net loss — — — — (70,492) — (70,492) Other comprehensive loss — — — — — (118) (118) Balances as of March 31, 2023 68,212,479 616,246 — 17,462 (161,616) 166 472,258 Issuance of common shares under equity incentive plan and employee share purchase plan 104,474 1,264 — (470) — — 794 Non-cash share-based compensation expense — — — 4,695 — — 4,695 Net loss — — — — (90,346) — (90,346) Other comprehensive loss — — — — — (146) (146) Balances as of June 30, 2023 68,316,953 617,510 — 21,687 (251,962) 20 387,255 Issuance of common shares under equity incentive plan and employee share purchase plan 47,190 1,251 — (520) — — 731 Non-cash share-based compensation expense — — — 4,456 — — 4,456 Net loss — — — — (102,574) — (102,574) Other comprehensive income — — — — — 138 138 Balance as of September 30, 2023 68,364,143 $ 618,761 $ — $ 25,623 $ (354,536) $ 158 $ 290,006 Common Shares Shares Amount Net Investment from Former Parent Additional Paid-in Capital Accumulated Deficit Accumulated Other Comprehensive Income Total Shareholders' Equity Balance as of December 31, 2021 — $ — $ 34,691 $ — $ — $ — $ 34,691 Net loss — — (97,032) — — — (97,032) Net transfers from Former Parent — — 108,440 — — — 108,440 Balance as of March 31, 2022 — — 46,099 — — — 46,099 Net loss — — (203,287) — — — (203,287) Net transfers from Former Parent — — 182,186 — — — 182,186 Balance as of June 30, 2022 — — 24,998 — — — 24,998 Net loss — — (68,853) — — — (68,853) Net transfers from Former Parent — — 144,071 — — — 144,071 Balance as of September 30, 2022 — $ — $ 100,216 $ — $ — $ — $ 100,216

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Schedule of activity in accumulated other comprehensive income (loss)	Shareholders’ equity included the following activity in accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2023: Three Months Ended September 30, 2023 Nine Months Ended September 30, 2023 Net unrealized investment gains (losses): Beginning of period balance $ (262) $ (145) Other comprehensive income before reclassifications (1) 178 22 Amounts reclassified from accumulated other comprehensive income (1)(2) — 39 Other comprehensive income (1) 178 61 End of period balance (84) (84) Foreign currency translation adjustments: Beginning of period balance 282 429 Other comprehensive loss (1) (40) (187) End of period balance 242 242 — Total beginning of period accumulated other comprehensive income 20 284 Total other comprehensive income (loss) 138 (126) Total end of period accumulated other comprehensive income $ 158 $ 158 (1) There was no tax on other comprehensive income (loss) and immaterial tax on amounts reclassified from accumulated other comprehensive income (loss) during the period.

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of basic and diluted net loss per share	Basic and diluted net loss per share attributable to common shareholders of Biohaven was calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Numerator: Net loss $ (102,574) $ (68,853) $ (263,412) $ (369,172) Denominator: Weighted average common shares outstanding—basic and diluted (1) 68,320,125 39,375,944 68,258,757 39,375,944 Net loss per share — basic and diluted $ (1.50) $ (1.75) $ (3.86) $ (9.38) (1) Prior to the Spin-Off from the Former Parent on October 3, 2022, Biohaven did not operate as an independent company. At the time of the Distribution, 39,375,944 common shares of the Company were distributed to the Former Parent's shareholders, including common shares issued in connection with Former Parent share options that were exercised on October 3, 2022 and common shares issued in connection with Former Parent restricted share units that vested on October 3, 2022. This number of shares is being utilized for the calculation of basic and diluted earnings per share for all periods presented prior to the Spin-Off.
Schedule of potentially anti-dilutive securities excluded from calculation of diluted net loss per share	The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common shareholders for the periods indicated because including them would have had an anti-dilutive effect: As of September 30, 2023 Options to purchase common shares 9,740,921

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Schedule of income tax provision and effective tax rate	The following table provides a comparative summary of the Company's income tax (benefit) provision and effective income tax rate for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Income tax (benefit) provision $ (3,287) $ 1,216 $ (171) $ 14,581 Effective income tax rate (3.1) % 1.8 % (0.1) % 4.1 %

Related Party Disclosures (Tabl

Related Party Disclosures (Tables)	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Schedule of related party transactions	For periods prior to the Separation, these allocations to the Company are reflected in the condensed consolidated statement of operations and comprehensive loss as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 Research and development $ 23,048 $ 84,772 General and administrative 9,676 43,053 Total $ 32,724 $ 127,825 Net transfers from Former Parent represent the net effect of transactions between the Company and the Former Parent prior to the Separation. The components of net transfers from Former Parent are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 General financing activities $ 111,816 $ 187,519 Corporate cost allocations, excluding share-based compensation 15,727 49,898 Net transfers from Former Parent as reflected in the Condensed Consolidated Statement of Cash Flows 127,543 237,417 Share-based compensation 16,997 77,927 Issuance of Former Parent common shares to repurchase non-controlling interest in a subsidiary — 60,000 Issuance of Former Parent common shares as payment for IPR&D asset acquisition — 58,747 Issuance of Former Parent common shares as payment for license and consulting agreements — 1,779 Other non-cash adjustments (469) (1,173) Net transfers from Former Parent as reflected in Note 7, "Shareholders' Equity" $ 144,071 $ 434,697

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation (Details) $ in Thousands		3 Months Ended	9 Months Ended
	Oct. 03, 2022 shares	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
Business Acquisition [Line Items]
Shares converted due to spinoff (in shares)	0.5
Shares issued in spinoff (in shares)	35,840,459
Shares issued in spinoff, former parent stock options (in shares)	2,611,392
Former Parent
Business Acquisition [Line Items]
Net transfers from Former Parent | $		$ 144,071		$ 434,697
Other Separation Related Adjustments | Former Parent
Business Acquisition [Line Items]
Net transfers from Former Parent | $			$ 27,811
RSUs
Business Acquisition [Line Items]
Shares issued in spinoff, former parent restricted stock options (in shares)	924,093

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Q Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Accounting Policies [Abstract]
Restricted cash held on behalf of Former Parent	$ 28	$ 35,212	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Cash and cash equivalents	$ 111,697	$ 204,877	$ 50,668
Restricted cash held on behalf of Former Parent	28	35,212	0
Restricted cash (included in other current assets)	11,890		0
Restricted cash (included in other non-current assets)	2,375		750
Total cash, cash equivalents and restricted cash at the end of the period in the condensed consolidated statement of cash flows	$ 125,990	$ 242,604	$ 51,418	$ 77,057

Marketable Securities - Amortiz

Marketable Securities - Amortized Cost and Fair Value of Debt Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value to Amortized Cost
Amortized Cost	$ 133,982	$ 310,505
Allowance for Credit Losses	0	0
Net Amortized Cost	133,982	310,505
Gross Unrealized Gains	3	51
Gross Unrealized Losses	(86)	(196)
Fair Value	133,899	310,360
Cash and cash equivalents
Fair Value to Amortized Cost
Fair Value	5,000	49,896
Marketable securities
Fair Value to Amortized Cost
Fair Value	128,899	260,464
U.S. corporate bonds
Fair Value to Amortized Cost
Amortized Cost	64,635	142,697
Allowance for Credit Losses	0	0
Net Amortized Cost	64,635	142,697
Gross Unrealized Gains	0	25
Gross Unrealized Losses	(62)	(135)
Fair Value	64,573	142,587
Foreign corporate bonds
Fair Value to Amortized Cost
Amortized Cost	24,623	36,766
Allowance for Credit Losses	0	0
Net Amortized Cost	24,623	36,766
Gross Unrealized Gains	0	9
Gross Unrealized Losses	(19)	(32)
Fair Value	24,604	36,743
U.S. treasury bills
Fair Value to Amortized Cost
Amortized Cost	39,759	89,308
Allowance for Credit Losses	0	0
Net Amortized Cost	39,759	89,308
Gross Unrealized Gains	3	17
Gross Unrealized Losses	0	(5)
Fair Value	39,762	89,320
U.S. agency bonds
Fair Value to Amortized Cost
Amortized Cost	4,965	41,734
Allowance for Credit Losses	0	0
Net Amortized Cost	4,965	41,734
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(5)	(24)
Fair Value	$ 4,960	$ 41,710

Marketable Securities - Contrac

Marketable Securities - Contractual Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Net Amortized Cost
Less than one year	$ 133,982	$ 310,505
Amortized Cost	133,982	310,505
Fair Value
Less than one year	133,899	310,360
Fair Value	$ 133,899	$ 310,360

Marketable Securities - Debt Se

Marketable Securities - Debt Securities Available-for-Sale in Unrealized Loss Position (Details) $ in Thousands	Sep. 30, 2023 USD ($) investment	Dec. 31, 2022 USD ($) investment
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Number of Securities, unrealized loss position less than 12 months | investment	17	24
Fair Value, unrealized loss position less than 12 months	$ 104,019	$ 187,866
Unrealized Losses, unrealized loss position less than 12 months	$ (86)	$ (196)
U.S. corporate bonds
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Number of Securities, unrealized loss position less than 12 months | investment	11	16
Fair Value, unrealized loss position less than 12 months	$ 64,573	$ 104,508
Unrealized Losses, unrealized loss position less than 12 months	$ (62)	$ (135)
Foreign corporate bonds
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Number of Securities, unrealized loss position less than 12 months | investment	3	3
Fair Value, unrealized loss position less than 12 months	$ 24,604	$ 31,886
Unrealized Losses, unrealized loss position less than 12 months	$ (19)	$ (32)
U.S. treasury bills
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Number of Securities, unrealized loss position less than 12 months | investment	2	1
Fair Value, unrealized loss position less than 12 months	$ 9,882	$ 9,762
Unrealized Losses, unrealized loss position less than 12 months	$ 0	$ (5)
U.S. agency bonds
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Number of Securities, unrealized loss position less than 12 months | investment	1	4
Fair Value, unrealized loss position less than 12 months	$ 4,960	$ 41,710
Unrealized Losses, unrealized loss position less than 12 months	$ (5)	$ (24)

Marketable Securities - Narrati

Marketable Securities - Narrative (Details) - investment	Sep. 30, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Investments in continuous unrealized loss position for more than twelve months	0	0

Marketable Securities - Net Inv

Marketable Securities - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Net investment income
Gross investment income	$ 3,831	$ 12,231
Investment expenses	(65)	(203)
Net investment income (excluding net realized capital losses)	3,766	12,028
Net realized capital losses	0	(39)
Net investment income	$ 3,766	$ 11,989

Marketable Securities - Proceed

Marketable Securities - Proceeds and Realized Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales	$ 0	$ 4,920
Gross realized capital losses	$ 0	$ 39

Fair Value of Financial Asset_3

Fair Value of Financial Assets and Liabilities - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Assets:
Total assets	$ 165,568	$ 383,226
Money market funds
Assets:
Cash and cash equivalents	29,794	72,866
Other non-current assets	1,875
U.S. treasury bills
Assets:
Cash and cash equivalents	5,000	39,948
Marketable securities	34,762	49,372
U.S. corporate bonds
Assets:
Cash and cash equivalents		9,948
Marketable securities	64,573	132,639
U.S. agency bonds
Assets:
Marketable securities	4,960	41,710
Foreign corporate bonds
Assets:
Marketable securities	24,604	36,743
Level 1
Assets:
Total assets	41,589	72,866
Level 1 | Money market funds
Assets:
Cash and cash equivalents	29,794	72,866
Other non-current assets	1,875
Level 1 | U.S. treasury bills
Assets:
Cash and cash equivalents	0	0
Marketable securities	9,920	0
Level 1 | U.S. corporate bonds
Assets:
Cash and cash equivalents		0
Marketable securities	0	0
Level 1 | U.S. agency bonds
Assets:
Marketable securities	0	0
Level 1 | Foreign corporate bonds
Assets:
Marketable securities	0	0
Level 2
Assets:
Total assets	123,979	310,360
Level 2 | Money market funds
Assets:
Cash and cash equivalents	0	0
Other non-current assets	0
Level 2 | U.S. treasury bills
Assets:
Cash and cash equivalents	5,000	39,948
Marketable securities	24,842	49,372
Level 2 | U.S. corporate bonds
Assets:
Cash and cash equivalents		9,948
Marketable securities	64,573	132,639
Level 2 | U.S. agency bonds
Assets:
Marketable securities	4,960	41,710
Level 2 | Foreign corporate bonds
Assets:
Marketable securities	24,604	36,743
Level 3
Assets:
Total assets	0	0
Level 3 | Money market funds
Assets:
Cash and cash equivalents	0	0
Other non-current assets	0
Level 3 | U.S. treasury bills
Assets:
Cash and cash equivalents	0	0
Marketable securities	0	0
Level 3 | U.S. corporate bonds
Assets:
Cash and cash equivalents		0
Marketable securities	0	0
Level 3 | U.S. agency bonds
Assets:
Marketable securities	0	0
Level 3 | Foreign corporate bonds
Assets:
Marketable securities	$ 0	$ 0

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ (7,335)	$ (4,914)
Property and equipment, net	17,669	17,512
Building and land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,728	11,728
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	680	569
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	780	780
Office and lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	9,148	5,501
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,491	1,202
Depreciable Property, Plant and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	23,827	19,780
Property and equipment, net	16,492	14,866
Equipment not yet in service
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,177	$ 2,646

Balance Sheet Components - Narr

Balance Sheet Components - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation	$ 857	$ 230	$ 2,421	$ 718
Computer software costs	760		760		$ 760
Accumulated amortization	$ 654		$ 654		$ 464

Balance Sheet Components - Othe

Balance Sheet Components - Other Non-current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Prepaid Expenses
Operating lease right-of-use assets	$ 32,330	$ 34,928
Other	2,377	2,585
Other non-current assets	$ 34,707	$ 37,513

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accrued Expense and Other Current Liabilities
Accrued employee compensation and benefits	$ 13,977	$ 14,603
Accrued clinical trial costs	27,945	17,788
Operating lease liability - current portion	3,281	3,019
Other accrued expenses and other current liabilities	7,431	8,696
Accrued expenses and other current liabilities	$ 52,634	$ 44,106

Acquisitions (Details)

Acquisitions (Details) - Channel - USD ($) $ in Thousands		3 Months Ended
	Apr. 04, 2022	Jun. 30, 2022
Business Acquisition [Line Items]
Upfront cash payment	$ 35,000
Stock issued in acquisition, number of shares	493,254
Stock issued in acquisition	$ 58,747
Potential developmental and regulatory milestones on BHV-7000	325,000
Potential developmental and regulatory milestones on Kv7 pipeline development	250,000
Potential commercial sales based milestones of BHV-7000	$ 562,500
Charge to research and development expense		$ 93,747
R&D expense		$ 25,000

Shareholders' Equity - Changes

Shareholders' Equity - Changes in Shareholders' Deficit (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (102,574)			$ (68,853)			$ (263,412)	$ (369,172)
Other comprehensive income (loss)	138			0			(126)	0
Total Shareholders' Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	387,255	$ 472,258	$ 538,771	24,998	$ 46,099	$ 34,691	538,771	34,691
Issuance of common shares under equity incentive plan	731	794	332
Share-based compensation	4,456	4,695	3,765
Net loss	(102,574)	(90,346)	(70,492)	(68,853)	(203,287)	(97,032)
Other comprehensive income (loss)	138	(146)	(118)
Net transfers from Former Parent				144,071	182,186	108,440
Ending balance	$ 290,006	$ 387,255	$ 472,258	$ 100,216	$ 24,998	$ 46,099	$ 290,006	$ 100,216
Common Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	68,316,953	68,212,479	68,190,479	0	0	0	68,190,479	0
Beginning balance	$ 617,510	$ 616,246	$ 615,742	$ 0	$ 0	$ 0	$ 615,742	$ 0
Issuance of common shares under equity incentive plan (shares)	47,190	104,474	22,000
Issuance of common shares under equity incentive plan	$ 1,251	$ 1,264	$ 504
Ending balance (in shares)	68,364,143	68,316,953	68,212,479	0	0	0	68,364,143	0
Ending balance	$ 618,761	$ 617,510	$ 616,246	$ 0	$ 0	$ 0	$ 618,761	$ 0
Net Investment from Former Parent
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0	0	24,998	46,099	34,691	0	34,691
Net loss				(68,853)	(203,287)	(97,032)
Net transfers from Former Parent				144,071	182,186	108,440
Ending balance	0	0	0	100,216	24,998	46,099	0	100,216
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	21,687	17,462	13,869	0	0	0	13,869	0
Issuance of common shares under equity incentive plan	(520)	(470)	(172)
Share-based compensation	4,456	4,695	3,765
Ending balance	25,623	21,687	17,462	0	0	0	25,623	0
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(251,962)	(161,616)	(91,124)	0	0	0	(91,124)	0
Net loss	(102,574)	(90,346)	(70,492)
Ending balance	(354,536)	(251,962)	(161,616)	0	0	0	(354,536)	0
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	20	166	284	0	0	0	284	0
Other comprehensive income (loss)	138	(146)	(118)
Ending balance	$ 158	$ 20	$ 166	$ 0	$ 0	$ 0	$ 158	$ 0

Shareholders' Equity - Narrativ

Shareholders' Equity - Narrative (Details) - Subsequent event - USD ($) $ / shares in Units, $ in Thousands	Oct. 05, 2023	Oct. 31, 2023
Common Shares
Sale of Stock [Line Items]
Equity Distribution Agreement aggregate amount		$ 150,000
Public offering
Sale of Stock [Line Items]
Common stock issued (shares)	11,761,363
Common stock sold, price per share (in dollars per share)	$ 22
Issuance of common shares, net of offering costs	$ 242,425

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
AOCI [Roll Forward]
Beginning of period balance		$ 538,771,000
End of period balance	$ 290,006,000	290,006,000
Accumulated other comprehensive income
AOCI [Roll Forward]
Beginning of period balance	20,000	284,000
Other comprehensive income (loss)	138,000	(126,000)
End of period balance	158,000	158,000
Tax on other comprehensive income (loss)	0
Net unrealized investment gains (losses):
AOCI [Roll Forward]
Beginning of period balance	(262,000)	(145,000)
Other comprehensive income (loss)	178,000	22,000
Amounts reclassified from accumulated other comprehensive income	0	39,000
Other comprehensive income (loss)	178,000	61,000
End of period balance	(84,000)	(84,000)
Foreign currency translation adjustments:
AOCI [Roll Forward]
Beginning of period balance	282,000	429,000
Other comprehensive income (loss)	(40,000)	(187,000)
End of period balance	$ 242,000	$ 242,000

Net Loss Per Share - Calculatio

Net Loss Per Share - Calculation of Basic and Diluted Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Oct. 02, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator:
Net loss		$ (102,574)	$ (68,853)	$ (263,412)	$ (369,172)
Denominator:
Common shares outstanding—basic (shares)	39,375,944	68,320,125	39,375,944	68,258,757	39,375,944
Common shares outstanding—diluted (shares)		68,320,125	39,375,944	68,258,757	39,375,944
Net loss per share attributable to common shareholders of Biohaven Pharmaceutical Holding Company Ltd. - basic (in dollars per share)		$ (1.50)	$ (1.75)	$ (3.86)	$ (9.38)
Net loss per share attributable to common shareholders of Biohaven Pharmaceutical Holding Company Ltd. - diluted (in dollars per share)		$ (1.50)	$ (1.75)	$ (3.86)	$ (9.38)

Net Loss Per Share - Antidiluti

Net Loss Per Share - Antidilutive Securities Excluded from Computation of Net Loss per Share (Details)	9 Months Ended
	Sep. 30, 2023 shares
Options to purchase common shares
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	9,740,921

License Agreements (Details)

License Agreements (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Milestone payment to be paid upon development achievement	$ 123,800
Milestone payment to be paid upon regulatory achievement	547,350
Milestone payment to be paid upon commercial achievement	1,270,450
Eligible development milestone payments	$ 1,325

License Agreements - Yale Unive

License Agreements - Yale University Agreement (Details) - USD ($)	1 Months Ended			3 Months Ended		9 Months Ended
	May 31, 2023	Jan. 31, 2021	May 31, 2019	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
License and other agreements
Milestone payment to be paid upon regulatory achievement				$ 547,350,000		$ 547,350,000
Research and development				95,517,000	$ 52,845,000	238,468,000	$ 300,028,000
Eligible development milestone payments				1,325,000		1,325,000
Yale University | Yale Arrangement
License and other agreements
Milestone payment to be paid upon regulatory achievement			$ 2,000,000
Minimum annual royalty payment to be paid upon sale of product			$ 1,000,000
Research and development				0	0	0	0
Yale University | Yale MoDE Agreement
License and other agreements
Minimum annual royalty payment to be paid upon sale of product		$ 1,000,000
Research and development				333,000	$ 333,000	1,000,000	$ 2,333,000
Eligible development milestone payments		800,000
Eligible commercial milestone payments		$ 2,950,000
Initial term of agreement (in years)		20 years
Amount of funding		$ 4,000,000
Yale University | Yale MoDE Agreement | License agreement
License and other agreements
Payment for license agreement		$ 1,000,000
Issuance of common shares as payment for assets (in shares)		11,668
Issuance of common shares as payment for assets		$ 1,000,000
Yale University | 2023 Yale SRA
License and other agreements
Research and development				$ 92,000		$ 245,000
Amount of funding	$ 612,000

License Agreements - ALS Biopha

License Agreements - ALS Biopharma Agreement (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2015 USD ($) prodrug claim	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
License and other agreements
Milestone payment to be paid upon regulatory achievement		$ 547,350,000		$ 547,350,000
Research and development		95,517,000	$ 52,845,000	238,468,000	$ 300,028,000
ALS Biopharma Agreement | Collaborative arrangement
License and other agreements
Number of prodrugs of glutamate modulating agents | prodrug	300
Milestone payment to be paid upon regulatory achievement	$ 3,000,000
Milestone payment to be paid for subsequently developed products	$ 1,000,000
Number of claims | claim	1
Research and development		$ 0	$ 0	$ 0	$ 0

License Agreements - AstraZenec

License Agreements - AstraZeneca License Agreement (Details) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 31, 2016	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
License and other agreements
Milestone payment to be paid upon regulatory achievement			$ 547,350,000		$ 547,350,000
Commercial milestone payment to be paid			1,270,450,000		1,270,450,000
Research and development			95,517,000	$ 52,845,000	238,468,000	$ 300,028,000
AstraZeneca
License and other agreements
Research and development			0	0	0	0
AstraZeneca | Collaborative arrangement
License and other agreements
Research and development			$ 0	$ 0	$ 0	$ 0
AstraZeneca | Collaborative arrangement | Maximum
License and other agreements
Milestone payment to be paid upon regulatory achievement		$ 30,000,000
Milestone payment to be paid for any product other than rimegepant		60,000,000
Commercial milestone payment to be paid		$ 120,000,000
Royalty percentage	10%
Agreement term after first commercial sale		10 years
AstraZeneca | Collaborative arrangement | Minimum
License and other agreements
Royalty percentage	0%
AstraZeneca | License agreement
License and other agreements
Payment for license agreement	$ 3,000,000
Issuance of common shares as payment for assets (in shares)	109,523
Issuance of common shares as payment for assets	$ 4,080,000
Milestone payment due upon achievement of specified regulatory and commercial milestones	55,000,000
Milestone payment due upon achievement of specified sales-based milestones	$ 50,000,000
AstraZeneca | License agreement | Maximum
License and other agreements
Royalty percentage	10%
AstraZeneca | License agreement | Minimum
License and other agreements
Royalty percentage	0%

License Agreements - Fox Chase

License Agreements - Fox Chase Chemical Diversity Center Agreement (Details) - USD ($)	1 Months Ended	3 Months Ended			9 Months Ended
	May 31, 2019	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Nov. 30, 2020
License and other agreements
Development milestone payment to be paid		$ 123,800,000			$ 123,800,000
Research and development		95,517,000		$ 52,845,000	238,468,000	$ 300,028,000
FCCDC Agreement
License and other agreements
Research and development		$ 0		$ 0	$ 0	$ 0
FCCDC Agreement | Collaborative arrangement
License and other agreements
Common stock issued (shares)	100,000
Issuance of common shares, net of offering costs	$ 5,646,000
Development milestone payment to be paid	3,000,000
Development milestone payments to be paid per each additional NDA filing	$ 1,000,000
FCCDC Agreement | Collaborative arrangement | Minimum
License and other agreements
Earned royalty payment per agreement (percent)							0%
FCCDC Agreement | Collaborative arrangement | Maximum
License and other agreements
Earned royalty payment per agreement (percent)							10%
FCCDC Warrants
License and other agreements
Number of securities called by warrants (shares)	100,000
Exercise price of warrants (in dollars per share)	$ 56.46
Research and development			$ 4,245,000

License Agreements - UCONN (Det

License Agreements - UCONN (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
License and other agreements
Commercial milestone payment to be paid		$ 1,270,450,000		$ 1,270,450,000
Research and development		95,517,000	$ 52,845,000	238,468,000	$ 300,028,000
UCONN
License and other agreements
Research and development		$ 0	0	$ 0	0
UCONN Agreement | UCONN
License and other agreements
Milestone payment to be paid upon developmental and regulatory achievement	$ 30,100,000
Commercial milestone payment to be paid	50,000,000		$ 50,000,000		$ 50,000,000
UCONN Agreement | UCONN | License agreement
License and other agreements
Payment for license agreement	$ 400,000

License Agreements - Artizan Bi

License Agreements - Artizan Biosciences Inc (Details) - USD ($)	1 Months Ended			3 Months Ended			9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jan. 31, 2021	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2020
License and other agreements
Development milestone payment to be paid				$ 123,800,000			$ 123,800,000
Commercial milestone payment to be paid				1,270,450,000			1,270,450,000
Research and development				95,517,000		$ 52,845,000	238,468,000	$ 300,028,000
Artizan Biosciences Inc
License and other agreements
Maximum number of preferred shares (in shares)	45,950,601
Proceeds from sale of stock	$ 8,000,000
Artizan Biosciences Inc
License and other agreements
Research and development				$ 0		$ 0	$ 0	$ 0
Artizan Biosciences Inc | Series A2 Preferred Stock
License and other agreements
Preferred shares paid (in shares)			61,494
Preferred shares paid			$ 6,000,000
Preferred shares received (in shares)			34,472,031
Artizan Biosciences Inc | Collaborative arrangement
License and other agreements
Option price	$ 4,000,000
Development milestone payment to be paid		$ 20,000,000
Additional development milestone payment to be paid		10,000,000			$ 10,000,000
Commercial milestone payment to be paid		$ 150,000,000
Percentage of funds raised for program	80%
Additional capital raise required	$ 35,000,000
Artizan Biosciences Inc | Collaborative arrangement | Series A2 Preferred Stock
License and other agreements
Preferred shares received (in shares)	22,975,301
Artizan Biosciences Inc | Collaborative arrangement | Minimum
License and other agreements
Option price									$ 4,000,000
Artizan Biosciences Inc | Collaborative arrangement | Maximum
License and other agreements
Option price									$ 8,000,000

License Agreements - Reliant Gl

License Agreements - Reliant Glycosciences LLC (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jul. 31, 2021	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
License and other agreements
Eligible development milestone payments		$ 1,325,000		$ 1,325,000
Research and development		95,517,000	$ 52,845,000	238,468,000	$ 300,028,000
Reliant Glycosciences, LLC
License and other agreements
Research and development		$ 0	$ 0	$ 0	$ 0
Reliant Glycosciences, LLC | Reliant Agreement
License and other agreements
Eligible development milestone payments	$ 36,500,000
Reliant Glycosciences, LLC | License agreement
License and other agreements
Issuance of common shares as payment for assets	$ 3,686,000

License Agreements - KU Leuven

License Agreements - KU Leuven (Details) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended
	Nov. 14, 2023	Jan. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
License and other agreements
Research and development			$ 95,517,000	$ 52,845,000	$ 238,468,000	$ 300,028,000
KU Leuven
License and other agreements
Research and development			0	$ 0	0	$ 0
KU Leuven | KU Leuven Agreement
License and other agreements
Development, regulatory and commercialization milestone payments		$ 327,750,000
Research and development			$ 1,250,000		$ 1,250,000
KU Leuven | KU Leuven Agreement | Subsequent event
License and other agreements
Research and development	$ 2,000,000
KU Leuven | License agreement | KU Leuven Agreement
License and other agreements
Payment for license agreement		$ 3,000,000
Issuance of common shares as payment for assets (in shares)		15,340
Issuance of common shares as payment for assets		$ 1,779,000

License Agreements - Taldefgrob

License Agreements - Taldefgrobep Alfa License Agreement (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Feb. 28, 2022
License and other agreements
Research and development	$ 95,517,000	$ 52,845,000	$ 238,468,000	$ 300,028,000
BMS
License and other agreements
Research and development	$ 0	$ 0	$ 0	$ 0
BMS | Taldefgrobep Alfa License Agreement
License and other agreements
Eligible milestone payment per agreement upon specified performance and regulatory milestones					$ 200,000,000

License Agreements - Hangzhou H

License Agreements - Hangzhou Highlightll Pharmaceutical Agreement (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
License and other agreements
Research and development		$ 95,517,000	$ 52,845,000	$ 238,468,000	$ 300,028,000
Highlightll Pharmaceutical Co, Ltd.
License and other agreements
Research and development		0	$ 0	0	$ 0
Highlightll Pharmaceutical Co, Ltd. | License agreement | Collaborative arrangement
License and other agreements
Payment obligation for license agreement		$ 10,000		$ 10,000
Obligation for issuance of common shares as payment for assets (in shares)		721,136		721,136
Obligation for issuance of common shares as payment for assets, value		$ 10,000,000		$ 10,000,000
Milestone payment due upon achievement of specified developmental, regulatory and commercial milestones, first indication	$ 200,000,000
Milestone payment due upon achievement of specified developmental, regulatory and commercial milestones, second indication	100,000,000
Milestone payment due upon achievement of specified sales-based milestones	$ 650,000,000

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($)		3 Months Ended		9 Months Ended
	Jan. 01, 2021	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Liability For Sale of Future Royalties [Line Items]
Eligible development milestone payments		$ 1,325,000		$ 1,325,000
Research and development		95,517,000	$ 52,845,000	238,468,000	$ 300,028,000
Moda Pharmaceuticals LLC | Moda Agreement
Liability For Sale of Future Royalties [Line Items]
Eligible development milestone payments	$ 81,612,000
Eligible commercial milestone payments	$ 30,171,000
Initial term of agreement (in years)	4 years
Moda Pharmaceuticals LLC | License agreement | Moda Agreement
Liability For Sale of Future Royalties [Line Items]
Payment for license agreement	$ 2,700,000
Issuance of common shares as payment for assets (in shares)	37,836
Issuance of common shares as payment for assets	$ 3,243,000
Artizan Biosciences Inc
Liability For Sale of Future Royalties [Line Items]
Research and development		$ 0	$ 0	0	$ 0
Research and Development Arrangement
Liability For Sale of Future Royalties [Line Items]
Research commitments				$ 11,475,000
Research commitment period				2 years

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
(Benefit) provision for income taxes	$ (3,287)	$ 1,216	$ (171)	$ 14,581
Effective income tax rate (percent)	(3.10%)	1.80%	(0.10%)	4.10%
Net operating loss carryforward	$ 598,679		$ 598,679

Related Party Transactions - Na

Related Party Transactions - Narrative (Details) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended
	May 31, 2023	Jan. 31, 2021	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Oct. 03, 2022
Related Party Transactions
Revenue from Former Parent			$ 1,233,000		$ 6,753,000
Restricted cash held on behalf of Former Parent			28,000	$ 0	28,000	$ 0	$ 35,212,000
Due to Former Parent			28,000		28,000		$ 35,212,000
Ending cash balance after former parent contribution								$ 257,799,000
Research and development expense			95,517,000	52,845,000	238,468,000	300,028,000
Yale University | Related Party
Related Party Transactions
Research and development expense			614,000	463,000	2,313,000	2,750,000
Due to related party			0		0
Transition Services | Former Parent
Related Party Transactions
Due from Former Parent			1,840,000		1,840,000
Yale University | Yale MoDE Agreement
Related Party Transactions
Amount of funding		$ 4,000,000
Research and development expense			333,000	$ 333,000	1,000,000	$ 2,333,000
Yale University | 2023 Yale SRA
Related Party Transactions
Amount of funding	$ 612,000
Research and development expense			$ 92,000		$ 245,000
Yale University | License agreement | Yale MoDE Agreement
Related Party Transactions
Payment for license agreement		$ 1,000,000
Issuance of common shares as payment for assets (in shares)		11,668
Issuance of common shares as payment for assets		$ 1,000,000

Related Party Transactions - Re

Related Party Transactions - Related Party Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Related Party Transactions
Research and development	$ 95,517	$ 52,845	$ 238,468	$ 300,028
Cost Allocations | Related Party
Related Party Transactions
Research and development		32,724		127,825
Research and development | Cost Allocations | Related Party
Related Party Transactions
Research and development		23,048		84,772
General and administrative | Cost Allocations | Related Party
Related Party Transactions
Research and development		$ 9,676		$ 43,053

Related Party Transactions - Ne

Related Party Transactions - Net Transfers from Parent (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Related Party Transactions
Net transfers from Former Parent as reflected in the Condensed Consolidated Statement of Cash Flows		$ 0	$ 237,417
Former Parent
Related Party Transactions
Net transfers from Former Parent as reflected in the Condensed Consolidated Statement of Cash Flows	$ 127,543		237,417
Net transfers from Former Parent as reflected in Note 7, "Shareholders' Equity"	144,071		434,697
Former Parent | General financing activities
Related Party Transactions
Net transfers from Former Parent as reflected in the Condensed Consolidated Statement of Cash Flows	111,816		187,519
Former Parent | Corporate cost allocations, excluding share-based compensation
Related Party Transactions
Net transfers from Former Parent as reflected in the Condensed Consolidated Statement of Cash Flows	15,727		49,898
Former Parent | Share-based compensation
Related Party Transactions
Net transfers from Former Parent as reflected in Note 7, "Shareholders' Equity"	16,997		77,927
Former Parent | Issuance of Former Parent common shares to repurchase non-controlling interest in a subsidiary
Related Party Transactions
Net transfers from Former Parent as reflected in Note 7, "Shareholders' Equity"	0		60,000
Former Parent | Issuance of Former Parent common shares as payment for IPR&D asset acquisition
Related Party Transactions
Net transfers from Former Parent as reflected in Note 7, "Shareholders' Equity"	0		58,747
Former Parent | Issuance of Former Parent common shares as payment for license and consulting agreements
Related Party Transactions
Net transfers from Former Parent as reflected in Note 7, "Shareholders' Equity"	0		1,779
Former Parent | Other non-cash adjustments
Related Party Transactions
Net transfers from Former Parent as reflected in Note 7, "Shareholders' Equity"	$ (469)		$ (1,173)