Replimune (REPL) 10-Q 12 Nov 24 2025 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Sep. 30, 2024	Nov. 08, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-38596
Entity Registrant Name	REPLIMUNE GROUP, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-2082553
Entity Address, Address Line One	500 Unicorn Park Drive
Entity Address, Address Line Two	Suite 303
Entity Address, City or Town	Woburn
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01801
City Area Code	781
Local Phone Number	222-9600
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	REPL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		68,417,444
Entity Central Index Key	0001737953
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q2

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2024	Mar. 31, 2024
Current assets:
Cash and cash equivalents	$ 113,494	$ 74,457
Short-term investments	318,565	346,211
Research and development incentives receivable	2,049	4,922
Prepaid expenses and other current assets	8,527	8,077
Total current assets	442,635	433,667
Property, plant and equipment, net	12,591	10,483
Research and development incentives receivable, non-current	832	0
Restricted cash	1,705	1,700
Right-to-use asset - operating leases	4,417	4,635
Right-to-use asset - financing leases	36,022	37,237
Total assets	498,202	487,722
Current liabilities:
Accounts payable	8,410	2,578
Accrued expenses and other current liabilities	31,423	33,981
Operating lease liabilities, current	1,199	1,161
Financing lease liabilities, current	2,758	2,718
Total current liabilities	43,790	40,438
Operating lease liabilities, non-current	3,502	3,771
Financing lease liabilities, non-current	23,093	23,410
Long term debt, net of discount	45,572	44,809
Other liabilities, non-current	786	786
Total liabilities	116,743	113,214
Commitments and contingencies (Note 14)
Stockholders' equity
Common stock, $0.001 par value; 150,000,000 shares authorized as of September 30, 2024 and March 31, 2024; 68,394,588 and 61,415,105 shares issued and outstanding as of September 30, 2024 and March 31, 2024, respectively	68	61
Additional paid-in capital	1,185,866	1,070,874
Accumulated deficit	(808,109)	(701,282)
Accumulated other comprehensive income	3,634	4,855
Total stockholders' equity	381,459	374,508
Total liabilities and stockholders' equity	$ 498,202	$ 487,722

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2024	Mar. 31, 2024
Stockholders' Equity Attributable to Parent [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	150,000,000	150,000,000
Common stock, issued (in shares)	68,394,588	61,415,105
Common stock, outstanding (in shares)	68,394,588	61,415,105

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating expenses:
Research and development	$ 43,448	$ 49,101	$ 86,420	$ 89,538
Selling, general and administrative	15,468	14,730	29,863	29,941
Total operating expenses	58,916	63,831	116,283	119,479
Loss from operations	(58,916)	(63,831)	(116,283)	(119,479)
Other income (expense):
Research and development incentives	408	443	846	836
Investment income	5,394	6,049	10,106	12,235
Interest expense on finance lease liability	(531)	(542)	(1,065)	(1,086)
Interest expense on debt obligations	(1,438)	(955)	(2,864)	(2,070)
Other income (expense)	2,028	(1,409)	2,433	(35)
Total other income (expense), net	5,861	3,586	9,456	9,880
Loss before income taxes	(53,055)	(60,245)	(106,827)	(109,599)
Income tax provision	0	(201)	0	0
Net loss	$ (53,055)	$ (60,044)	$ (106,827)	$ (109,599)
Net loss per common share, basic (in dollars per share)	$ (0.68)	$ (0.90)	$ (1.45)	$ (1.65)
Net loss per common share, diluted (in dollars per share)	$ (0.68)	$ (0.90)	$ (1.45)	$ (1.65)
Weighted average common shares outstanding, basic (in shares)	78,570,135	66,582,280	73,903,650	66,475,577
Weighted average common shares outstanding, diluted (in shares)	78,570,135	66,582,280	73,903,650	66,475,577

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (53,055)	$ (60,044)	$ (106,827)	$ (109,599)
Other comprehensive loss:
Foreign currency translation (loss) gain	(1,905)	1,308	(2,337)	3
Net unrealized gain (loss) on short-term investments, net of tax of $0	1,215	214	1,116	(244)
Comprehensive loss	$ (53,745)	$ (58,522)	$ (108,048)	$ (109,840)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Tax on short-term investments	$ 0	$ 0	$ 0	$ 0

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss
Balance (in shares) at Mar. 31, 2023		56,676,313
Balance at Mar. 31, 2023	$ 555,292	$ 57	$ 1,034,994	$ (485,488)	$ 5,729
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment	(1,305)				(1,305)
Unrealized gain (loss) on short-term investments	(458)				(458)
Exercise of pre-funded warrants (in shares)		1,922,655
Exercise of stock options (in shares)		96,146
Exercise of stock options	1,209		1,209
Vesting of RSUs (in shares)		281,211
Stock-based compensation expense	8,846		8,846
Net loss	(49,555)			(49,555)
Balance (in shares) at Jun. 30, 2023		58,976,325
Balance at Jun. 30, 2023	514,029	$ 57	1,045,049	(535,043)	3,966
Balance (in shares) at Mar. 31, 2023		56,676,313
Balance at Mar. 31, 2023	555,292	$ 57	1,034,994	(485,488)	5,729
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment	3
Unrealized gain (loss) on short-term investments	(244)
Net loss	(109,599)
Balance (in shares) at Sep. 30, 2023		59,059,343
Balance at Sep. 30, 2023	465,172	$ 59	1,054,712	(595,087)	5,488
Balance (in shares) at Jun. 30, 2023		58,976,325
Balance at Jun. 30, 2023	514,029	$ 57	1,045,049	(535,043)	3,966
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment	1,308				1,308
Unrealized gain (loss) on short-term investments	214				214
Exercise of stock options (in shares)		67,210
Exercise of stock options	550	$ 1	549
Vesting of RSUs (in shares)		15,808
Vesting of RSUs	1	$ 1
Stock-based compensation expense	9,114		9,114
Net loss	(60,044)			(60,044)
Balance (in shares) at Sep. 30, 2023		59,059,343
Balance at Sep. 30, 2023	465,172	$ 59	1,054,712	(595,087)	5,488
Balance (in shares) at Mar. 31, 2024		61,415,105
Balance at Mar. 31, 2024	374,508	$ 61	1,070,874	(701,282)	4,855
Increase (decrease) in Stockholders' Equity
Issuance of prefunded warrants to purchase common stock, net of issuance costs	48,500		48,500
Issuance of common stock in connection with private placement, net of placement agent fees and offering costs (in shares)		5,668,937
Issuance of common stock in connection with private placement, net of placement agent fees and offering costs	48,204	$ 6	48,198
Foreign currency translation adjustment	(432)				(432)
Unrealized gain (loss) on short-term investments	(99)				(99)
Exercise of pre-funded warrants (in shares)		739,225
Exercise of pre-funded warrants	1	$ 1
Exercise of stock options (in shares)		22,860
Exercise of stock options	66		66
Vesting of RSUs (in shares)		463,841
Stock-based compensation expense	9,475		9,475
Net loss	(53,772)			(53,772)
Balance (in shares) at Jun. 30, 2024		68,309,968
Balance at Jun. 30, 2024	426,451	$ 68	1,177,113	(755,054)	4,324
Balance (in shares) at Mar. 31, 2024		61,415,105
Balance at Mar. 31, 2024	374,508	$ 61	1,070,874	(701,282)	4,855
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment	(2,337)
Unrealized gain (loss) on short-term investments	$ 1,116
Exercise of stock options (in shares)	57,144
Net loss	$ (106,827)
Balance (in shares) at Sep. 30, 2024		68,394,588
Balance at Sep. 30, 2024	381,459	$ 68	1,185,866	(808,109)	3,634
Balance (in shares) at Jun. 30, 2024		68,309,968
Balance at Jun. 30, 2024	426,451	$ 68	1,177,113	(755,054)	4,324
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment	(1,905)				(1,905)
Unrealized gain (loss) on short-term investments	1,215				1,215
Exercise of stock options (in shares)		34,284
Exercise of stock options	103		103
Vesting of RSUs (in shares)		50,336
Stock-based compensation expense	8,650		8,650
Net loss	(53,055)			(53,055)
Balance (in shares) at Sep. 30, 2024		68,394,588
Balance at Sep. 30, 2024	$ 381,459	$ 68	$ 1,185,866	$ (808,109)	$ 3,634

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net loss	$ (106,827)	$ (109,599)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	18,125	17,961
Depreciation and amortization	1,661	1,275
Net amortization of premiums and discounts on short-term investments	(5,215)	(6,459)
Noncash interest expense	758	513
Unrealized foreign currency transaction (gains) losses	(2,433)	37
Changes in operating assets and liabilities:
Research and development incentives receivable	2,241	(835)
Prepaid expenses and other current assets	(407)	(2,243)
Operating lease, right-of-use-asset	333	300
Finance lease, right-of-use-asset	1,214	1,214
Accounts payable	5,849	(1,029)
Accrued expenses and other current liabilities	(2,755)	6,977
Operating lease liabilities	(350)	(290)
Net cash used in operating activities	(87,806)	(92,178)
Cash flows from investing activities:
Purchases of property, plant and equipment and software capitalization	(3,753)	(2,203)
Purchase of short-term investments	(194,933)	(281,246)
Proceeds from sales and maturities of short-term investments	228,910	303,493
Net cash provided by investing activities	30,224	20,044
Cash flows from financing activities:
Proceeds from issuance of common stock in connection with private placement, net of placement agent fees and offering costs	48,204	0
Proceeds from issuance of prefunded warrants to purchase common stock, net of placement agent fees and offering costs	48,500	0
Principal payment of finance lease obligation	(277)	(217)
Proceeds from exercise of stock options and pre-funded warrants	171	1,760
Net cash provided by financing activities	96,598	1,543
Effect of exchange rate changes on cash, cash equivalents and restricted cash	26	(3)
Net increase (decrease) in cash, cash equivalents and restricted cash	39,042	(70,594)
Cash, cash equivalents and restricted cash at beginning of period	76,157	148,226
Cash, cash equivalents and restricted cash at end of period	115,199	77,632
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	2,864	1,343
Cash paid for income taxes, net	0	300
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses	$ 120	$ 138

Nature of the business

Nature of the business	6 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the business	Nature of the business Replimune Group, Inc. (the “Company”) is a clinical-stage biotechnology company with the mission to transform cancer treatment by pioneering the development of a novel portfolio of oncolytic immunotherapies. The Company's proprietary oncolytic immunotherapy product candidates are designed and intended to maximally activate the immune system against cancer. Replimune Group, Inc., whose predecessor was founded in 2015, is the parent company of its wholly owned, direct and indirect subsidiaries: Replimune Limited (“Replimune UK”); Replimune, Inc. (“Replimune US”); Replimune Securities Corporation; and Replimune (Ireland) Limited. The Company is subject to risks and uncertainties common to early-stage 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, third-party intellectual property, 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 require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance and reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from product sales. The Company's proprietary oncolytic immunotherapy product candidates, the RPx product candidates, are based on a novel, engineered strain of herpes simplex virus 1, or HSV-1, backbone with added payloads intended to maximize immunogenic cell death and the induction of a systemic anti-tumor immune response. The Company currently has three RPx product candidates, RP1, RP2 and RP3. RP1 is currently under development in multiple clinical trials, the most advanced being the anti-PD1 failed melanoma cohort of the IGNYTE clinical trial. Basis of presentation The accompanying consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. The Company has incurred recurring losses since its inception, including net losses of $53.1 million and $60.0 million for the three months ended September 30, 2024 and 2023, and net losses of $106.8 million and $109.6 million for the six months ended September 30, 2024 and 2023, respectively. In addition, as of September 30, 2024, the Company had an accumulated deficit of $808.1 million. The Company expects to continue to generate operating losses for the foreseeable future. As of the issuance date of these consolidated financial statements, the Company expects that its cash and cash equivalents and short-term investments will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance of these consolidated financial statements.

Summary of significant accounti

Summary of significant accounting policies	6 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of significant accounting policies	Summary of significant accounting policies Principles of consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and include the accounts of the Company and its direct and indirect wholly owned subsidiaries, Replimune UK, Replimune US, Replimune Securities Corporation and Replimune (Ireland) Limited after elimination of all intercompany accounts and transactions. Use of estimates The preparation of 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 consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual for research and development expenses and the valuation of stock-based awards. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. Unaudited interim financial information The accompanying consolidated balance sheet as of September 30, 2024, the consolidated statements of operations, of comprehensive loss and of stockholders’ equity for the three and six months ended September 30, 2024 and 2023 and the consolidated statements of cash flows for the six months ended September 30, 2024 and 2023 are unaudited. The unaudited interim 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 presentation of the Company’s financial position as of September 30, 2024 and the results of its operations for the three and six months ended September 30, 2024 and 2023 and its cash flows for the six months ended September 30, 2024 and 2023. The financial data and other information disclosed in these consolidated notes related to the three and six months ended September 30, 2024 and 2023 are unaudited. The results for the three and six months ended September 30, 2024 are not necessarily indicative of results to be expected for the year ending March 31, 2025, 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 March 31, 2024, which was filed with the Securities and Exchange Commission on May 16, 2024 (the "Annual Report"). During the three and six months ended September 30, 2024, there have been no changes to the Company’s significant accounting policies as described in the Annual Report. Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update ("ASU") No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” This ASU updates income tax disclosure requirements primarily by requiring specific categories and greater disaggregation within the rate reconciliation and disaggregation of income taxes paid by jurisdiction. This ASU is effective for annual periods beginning after December 15, 2024 and is applicable to the Company’s fiscal year beginning April 1, 2025, with early application permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures. In November 2023, the FASB issued ASU 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures". The amendments in this update expand segment disclosure requirements, including new segment disclosure requirements for entities with a single reportable segment among other disclosure requirements. This update is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. The Company is currently evaluating the potential impact of this adoption on the consolidated financial statements and related disclosures. In November 2024, the FASB issued an ASU to require more detailed information about specified categories of expenses (purchases of inventory, employee compensation, depreciation, amortization, and depletion) included in certain expense captions presented on the face of the income statement. This ASU is effective for fiscal years beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. The amendments may be applied either (1) prospectively to financial statements issued for reporting periods after the effective date of this ASU or (2) retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and related disclosures.

Fair value of financial assets

Fair value of financial assets and liabilities	6 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair value of financial assets and liabilities	Fair value of financial assets and liabilities The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements as of Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ — $ 23,549 $ — $ 23,549 Short-term investments US Government Agency bonds — 119,628 — 119,628 US Treasury bonds — 198,937 — 198,937 $ — $ 342,114 $ — $ 342,114 Fair Value Measurements as of Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ — $ 41,077 $ — $ 41,077 Short-term investments US Government Agency bonds — 199,821 — 199,821 US Treasury bonds — 146,390 — 146,390 $ — $ 387,288 $ — $ 387,288 The underlying securities in the money market funds held by the Company are all government backed securities. During the three and six months ended September 30, 2024 and 2023, there were no transfers between levels. Valuation of cash equivalents and short-term investments Money market funds, U.S. Government Agency bonds and U.S. Treasury bonds were valued by the Company using quoted prices in active markets for similar securities, which represent a Level 2 measurement within the fair value hierarchy. Cash equivalents consisted of money market funds at September 30, 2024 and money market funds at March 31, 2024.

Short-term investments

Short-term investments	6 Months Ended
	Sep. 30, 2024
Short-Term Investments [Abstract]
Short-term investments	Short-term investments As of September 30, 2024 and March 31, 2024, the Company's available-for-sale investments by type consisted of the following: September 30, 2024 Amortized Gross unrealized Gross unrealized Credit Losses Fair value US Government agency bonds $ 119,416 $ 213 $ (1) $ — $ 119,628 US Treasury bonds 198,144 794 (1) — 198,937 Total $ 317,560 $ 1,007 $ (2) $ — $ 318,565 March 31, 2024 Amortized cost Gross unrealized gains Gross unrealized losses Credit Losses Fair value US Government agency bonds 199,905 33 (117) $ — 199,821 US Treasury bonds 146,417 11 (38) — 146,390 Total $ 346,322 $ 44 $ (155) $ — $ 346,211 As of September 30, 2024 and March 31, 2024, available-for-sale securities consisted of investments that mature within one year.

Property, plant and equipment,

Property, plant and equipment, net	6 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Property, plant and equipment, net	Property, plant and equipment, net Property, plant and equipment, net consisted of the following: September 30, 2024 March 31, 2024 Office equipment $ 1,487 $ 1,464 Computer equipment 2,108 1,975 Plant and laboratory equipment 10,747 10,423 Leasehold improvements 1,853 1,886 Capitalized software 6,441 3,515 Construction in progress 1,513 1,117 Total property, plant and equipment 24,149 20,380 Less: Accumulated depreciation (11,558) (9,897) Property, plant and equipment, net $ 12,591 $ 10,483 Depreciation and amortization expense was $0.9 million and $1.7 million for the three and six months ended September 30, 2024 and $0.7 million and $1.3 million for the three and six months ended September 30, 2023, respectively. Amortization on capitalized software for the three and six months ended September 30, 2024 was $0.1 million and $0.1 million, respectively. The Company did not incur any amortization on capitalized software in the prior year. Depreciation and amortization expense is recorded within research and development and selling, general and administrative expenses in the consolidated statement of operations.

Accrued expenses and other curr

Accrued expenses and other current liabilities	6 Months Ended
	Sep. 30, 2024
Accrued Liabilities and Other Liabilities [Abstract]
Accrued expenses and other current liabilities	Accrued expenses and other current liabilities Accrued expenses and other current liabilities consisted of the following: September 30, 2024 March 31, 2024 Accrued research and development costs $ 16,410 $ 16,376 Accrued compensation and benefits costs 9,684 13,906 Accrued professional fees 516 369 Other 4,813 3,330 Total accrued expenses and other current liabilities $ 31,423 $ 33,981

Debt

Debt	6 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Debt	Debt On October 6, 2022, the Company entered into a Loan and Security Agreement (the “Loan Agreement”), with Hercules Capital, Inc., as administrative agent, collateral agent and as a lender (“Hercules”). Pursuant to the Loan Agreement, the Company can borrow term loans in an aggregate maximum principal amount of up to $200.0 million under multiple tranches (the “Term Loan Facility”). Under the Loan Agreement, the Company borrowed an initial amount of $30.0 million on the closing date, and at the Company's sole option, could have drawn, but did not draw down, an additional $30.0 million on or prior to September 30, 2023. The Company can also draw as additional term loan advances in an aggregate principal amount of up to $115.0 million during the term of the Term Loan Facility subject to achievement of specified performance milestones, and two additional term loan advances up to an aggregate principal amount of $25.0 million subject to certain terms and conditions, on or prior to the end of the interest-only period. The Company intends to use the proceeds of the Term Loan Facility for working capital and general corporate purposes. The Loan Agreement was subsequently amended (the "Amendment") on June 28, 2023 pursuant to which the Company agreed to draw an initial term loan advance in an aggregate principal amount not less than $30.0 million, provided that the aggregate amount of the term loan advances made under tranche 1 do not exceed $30.0 million, which reflects a decrease of $30 million from the $60.0 million in the original Loan Agreement for tranche 1. The total amount of the Loan Agreement, as well as the outstanding balance of the loan, is unchanged, but the option to borrow additional funds were redistributed from tranche 1 to tranche 2. The impact of this amendment is not a modification, as it does not relate to outstanding debt, but is rather an amendment that provides for a future potential benefit. There is no material impact to the financial statements as a result of the Amendment. A second amendment was made to the Loan Agreement (the "Second Amendment") on December 22, 2023 pursuant to which the Company agreed to draw a term loan advance in an aggregate principal amount not less than $15.0 million, provided that the aggregate amount of the term loan advances made under tranche 2 do not exceed $15.0 million on or prior to December 31, 2023. The Second Amendment re-allocated the total future consideration of the Loan Agreement to the future tranches extending through September 2026, subject to the terms and conditions of the Loan Agreement. The Second Amendment did not change the total aggregate maximum principal amount to be drawn under the Loan Agreement, which remains as up to $200.0 million. The Company evaluated the Second Amendment as a modification under relevant accounting guidance, and based on that analysis and the immaterial change in cash flows on current outstanding debt, it was determined that there was no material accounting impact. Upon closing of the Second Amendment, the Company drew down the tranche 2 amount of $15.0 million. The Term Loan Facility will mature on October 1, 2027 (the “Maturity Date”). The outstanding principal balance of the Term Loan Facility bears interest payable in cash at a floating rate per annum equal to the greater of (i) 7.25% and (ii) the sum of the Prime Rate (which is capped at 7.25%) and 1.75%. Accrued interest is payable monthly following the funding of each term loan advance. In addition, the principal balance of the Term Loan Facility will bear “payment-in-kind” interest at the rate of 1.50% (“PIK Interest”), which PIK Interest will be added to the outstanding principal balance of the Term Loan Facility on each interest payment date. Borrowings under the Loan Agreement are repayable in monthly interest-only payments through September 2026. After the interest-only payment period, borrowings under the Loan Agreement are repayable in equal monthly payments of principal and accrued interest until October 2027. At the Company's option, the Company may prepay all or a portion of the outstanding borrowings, subject to a prepayment fee of 3.0% of the principal amount if prepayment had occurred during the 12 months following the closing date, 2.0% after 12 months following the closing date but prior to 36 months following the closing date, and 1.0% thereafter. The Loan Agreement contains customary facility fees, events of default and representations, warranties and affirmative and negative covenants, including a financial covenant requiring the Company to maintain unrestricted cash in an amount not less than 35% of the aggregate outstanding secured obligations under the Loan Agreement in accounts subject to a control agreement in favor of the Agent (the “Unrestricted Cash”) at all times which commenced on January 1, 2024. In addition, the Loan Agreement also contains a financial covenant that beginning on the later of (i) July 1, 2024 and (ii) the date on which the aggregate outstanding principal amount of the Term Loan Facility is equal to or greater than $100.0 million, the Company is required to satisfy one of the following requirements: (1) achieve a minimum amount of trailing three-month net product revenue tested on a monthly basis, (2) maintain a market capitalization in excess of $1.2 billion and Unrestricted Cash in an amount no less than 50% of the outstanding amount under the Term Loan Facility, or (3) maintain Unrestricted Cash in an amount no less than 85% of the outstanding amount under the Term Loan Facility. The Company paid a $0.5 million facility charge and incurred debt issuance costs of $1.5 million upon closing of the Loan Agreement. The Loan Agreement also provides for a final payment, payable upon maturity or the repayment of the obligations in full or in part (on a pro rata basis), equal to 4.95% of the aggregate principal amount of Term Loans advanced to the Company and repaid on such date, which is being accrued on the Company's consolidated balance sheet. The amount accrued for the final payment is $0.8 million as of September 30, 2024 and $0.5 million as of March 31, 2024. Unamortized debt issuance costs are recorded as a reduction of the carrying amount on the term loan and amortized as interest expense using the effective-interest method. In addition, unamortized deferred financing costs of $1.1 million and $1.2 million were recorded in other assets as of September 30, 2024 and March 31, 2024, respectively, related to the Company's right to borrow additional amounts from Hercules in the future and amortized to interest expense over the relevant draw period on a straight-line basis. Interest expense for the three and six months ended September 30, 2024 was $1.4 million and $2.9 million, respectively, and $1.0 million and $2.1 million, respectively, for the three and six months ended September 30, 2023. The summary of obligations under the term loan as of September 30, 2024 and March 31, 2024 consisted of the following (in thousands): September 30, 2024 March 31, 2024 Principal loan balance $ 46,099 $ 45,749 Facility charge and diligence fee (236) (266) Unamortized issuance costs (1,058) (1,191) Accumulated end of term fee 767 517 Long term debt, net $ 45,572 $ 44,809 The annual principal payments due under the Loan Agreement as of fiscal September 30, 2024 and March 31, 2024 were as follows: September 30, 2024 March 31, 2024 2025 — — 2026 — — 2027 20,145 20,145 2028 27,769 27,769 Total $ 47,914 $ 47,914

Stockholders' equity

Stockholders' equity	6 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Stockholders' equity	Stockholders’ equity Common stock As of September 30, 2024 and March 31, 2024, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue up to 150,000,000 shares of common stock, par value $0.001 per share. The Company had reserved for common stock for the exercise of outstanding stock options and the vesting of restricted stock units, the number of shares remaining available for grant under the Company’s 2018 Omnibus Incentive Compensation Plan and the Company’s Employee Stock Purchase Plan (see Note 10) and the exercise of the outstanding warrants to purchase shares of common stock as follows: September 30, 2024 March 31, 2024 Stock options, issued and outstanding 10,232,085 8,652,256 Restricted and performance stock units 3,496,654 2,397,890 Stock options and restricted stock units, future issuance 1,841,705 2,284,141 Employee stock purchase plan, available for future grants 3,405,175 2,738,208 Pre-IPO warrants to purchase common stock 497,344 497,344 Pre-funded warrants 10,211,969 5,281,616 Total shares of common stock reserved for future issuance 29,684,932 21,851,455 Undesignated preferred stock As of September 30, 2024, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue up to 10,000,000 shares of undesignated preferred stock, par value $0.001 per share. There were no undesignated preferred shares issued or outstanding as of September 30, 2024. ATM program On August 3, 2023, the Company and Leerink Partners LLC (the "Current Agent") entered into a sales agreement, which was subsequently amended on May 16, 2024 (as so amended, the "2023 Sales Agreement"). Under the 2023 Sales Agreement, the Company may sell, from time to time, at its option, up to an aggregate of $100.0 million of share of the Company's common stock, $0.001 par value shares (the "Shares"), through the Current Agent, as the Company's sales agent. Any Shares to be offered and sold under the 2023 Sales Agreement will be issued and sold (i) by methods deemed to be an “at the market offering” (“ATM”) as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended, or if authorized by the Company, in negotiated transactions or block trades, and (ii) pursuant to a registration statement on Form S-3 filed by the Company with the Securities and Exchange Commission on August 3, 2023, as amended for an offering of various securities, including shares of the Company’s common stock, preferred stock, debt securities, warrants and/or units for sale to the public in one or more public offerings. Subject to the terms of the 2023 Sales Agreement, the Current Agent will use reasonable efforts to sell the Shares from time to time, based upon the Company’s instructions (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company will pay the Current Agent a commission of up to 3.0% of the gross proceeds from the sale of the Shares. The Company has also agreed to provide the Current Agent with customary indemnification rights. During the three and six months ended September 30, 2024, the Company did not issue or sell any shares under the 2023 Sales Agreement. The Company cannot provide any assurances that it will issue any additional Shares pursuant to the 2023 Sales Agreement. Equity offerings On June 14, 2024, the Company completed a private placement transaction (the "Private Placement") pursuant to which the Company sold (a) 5,668,937 shares of the Company's common stock, at an offering price of $8.82, and (b) in lieu of common stock to certain investors, pre-funded warrants to purchase 5,669,578 shares of the Company's common stock at an offering price of $8.819 per warrant (the "2024 Pre-funded Warrants"). The Company received aggregate net proceeds in the Private Placement of approximately $96.7 million after deducting placement agent fees and other offering expenses payable by the Company of approximately $3.3 million. Pre-funded Warrants The Company's pre-funded warrants are exercisable at any time after the date of issuance. Unless otherwise modified by a holder of a pre-funded warrant, no holder may exercise a pre-funded warrant if such holder, together with its affiliates, would beneficially own more than 9.99% of the number of shares of the Company’s common stock outstanding immediately after giving effect to such exercise. A holder of the 2024 Pre-funded Warrants may increase or decrease this percentage to any other percentage not in excess of 9.99%, whereas a holder of the Company's pre-funded warrants issued prior to the 2024 Pre-funded Warrants, may increase or decrease this percentage up to 19.99%, by providing at least 61 days’ prior notice to the Company. The 10,211,969 shares of the Company's common stock underlying the pre-funded warrants issued by the Company are not included in the number of issued and outstanding shares of the Company’s common stock outstanding as reported on the consolidated balance sheet, though they are included in the Company's annual pool increase calculation as well as the weighted average outstanding common stock in the calculation of basic and diluted net loss per share, as described below in Note 11. During the six months ended September 30, 2024, a holder of the Company's pre-funded warrants exercised 739,225 of its pre-funded warrants for an exercise price of $0.001 per pre-funded warrant and the Company issued 739,225 shares of Common Stock in exchange thereof.

Pre-funded Warrants

Pre-funded Warrants	6 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Pre-funded Warrants	Stockholders’ equity Common stock As of September 30, 2024 and March 31, 2024, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue up to 150,000,000 shares of common stock, par value $0.001 per share. The Company had reserved for common stock for the exercise of outstanding stock options and the vesting of restricted stock units, the number of shares remaining available for grant under the Company’s 2018 Omnibus Incentive Compensation Plan and the Company’s Employee Stock Purchase Plan (see Note 10) and the exercise of the outstanding warrants to purchase shares of common stock as follows: September 30, 2024 March 31, 2024 Stock options, issued and outstanding 10,232,085 8,652,256 Restricted and performance stock units 3,496,654 2,397,890 Stock options and restricted stock units, future issuance 1,841,705 2,284,141 Employee stock purchase plan, available for future grants 3,405,175 2,738,208 Pre-IPO warrants to purchase common stock 497,344 497,344 Pre-funded warrants 10,211,969 5,281,616 Total shares of common stock reserved for future issuance 29,684,932 21,851,455 Undesignated preferred stock As of September 30, 2024, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue up to 10,000,000 shares of undesignated preferred stock, par value $0.001 per share. There were no undesignated preferred shares issued or outstanding as of September 30, 2024. ATM program On August 3, 2023, the Company and Leerink Partners LLC (the "Current Agent") entered into a sales agreement, which was subsequently amended on May 16, 2024 (as so amended, the "2023 Sales Agreement"). Under the 2023 Sales Agreement, the Company may sell, from time to time, at its option, up to an aggregate of $100.0 million of share of the Company's common stock, $0.001 par value shares (the "Shares"), through the Current Agent, as the Company's sales agent. Any Shares to be offered and sold under the 2023 Sales Agreement will be issued and sold (i) by methods deemed to be an “at the market offering” (“ATM”) as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended, or if authorized by the Company, in negotiated transactions or block trades, and (ii) pursuant to a registration statement on Form S-3 filed by the Company with the Securities and Exchange Commission on August 3, 2023, as amended for an offering of various securities, including shares of the Company’s common stock, preferred stock, debt securities, warrants and/or units for sale to the public in one or more public offerings. Subject to the terms of the 2023 Sales Agreement, the Current Agent will use reasonable efforts to sell the Shares from time to time, based upon the Company’s instructions (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company will pay the Current Agent a commission of up to 3.0% of the gross proceeds from the sale of the Shares. The Company has also agreed to provide the Current Agent with customary indemnification rights. During the three and six months ended September 30, 2024, the Company did not issue or sell any shares under the 2023 Sales Agreement. The Company cannot provide any assurances that it will issue any additional Shares pursuant to the 2023 Sales Agreement. Equity offerings On June 14, 2024, the Company completed a private placement transaction (the "Private Placement") pursuant to which the Company sold (a) 5,668,937 shares of the Company's common stock, at an offering price of $8.82, and (b) in lieu of common stock to certain investors, pre-funded warrants to purchase 5,669,578 shares of the Company's common stock at an offering price of $8.819 per warrant (the "2024 Pre-funded Warrants"). The Company received aggregate net proceeds in the Private Placement of approximately $96.7 million after deducting placement agent fees and other offering expenses payable by the Company of approximately $3.3 million. Pre-funded Warrants The Company's pre-funded warrants are exercisable at any time after the date of issuance. Unless otherwise modified by a holder of a pre-funded warrant, no holder may exercise a pre-funded warrant if such holder, together with its affiliates, would beneficially own more than 9.99% of the number of shares of the Company’s common stock outstanding immediately after giving effect to such exercise. A holder of the 2024 Pre-funded Warrants may increase or decrease this percentage to any other percentage not in excess of 9.99%, whereas a holder of the Company's pre-funded warrants issued prior to the 2024 Pre-funded Warrants, may increase or decrease this percentage up to 19.99%, by providing at least 61 days’ prior notice to the Company. The 10,211,969 shares of the Company's common stock underlying the pre-funded warrants issued by the Company are not included in the number of issued and outstanding shares of the Company’s common stock outstanding as reported on the consolidated balance sheet, though they are included in the Company's annual pool increase calculation as well as the weighted average outstanding common stock in the calculation of basic and diluted net loss per share, as described below in Note 11. During the six months ended September 30, 2024, a holder of the Company's pre-funded warrants exercised 739,225 of its pre-funded warrants for an exercise price of $0.001 per pre-funded warrant and the Company issued 739,225 shares of Common Stock in exchange thereof.

Stock-based compensation

Stock-based compensation	6 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-based compensation	Stock-based compensation Stock-based compensation expense Stock-based compensation expense was classified in the consolidated statements of operations as follows: Three Months Ended Six Months Ended 2024 2023 2024 2023 Research and development $ 4,078 $ 4,447 $ 8,304 $ 7,745 Selling, general and administrative 4,572 4,667 9,821 10,216 $ 8,650 $ 9,114 $ 18,125 $ 17,961 The following table summarizes stock-based compensation expense by award type for the three and six months ended September 30, 2024 and 2023: Three Months Ended Six Months Ended September 30, 2024 2023 2024 2023 Stock options $ 4,894 $ 5,688 $ 10,627 $ 11,302 Restricted and performance stock units 3,756 3,426 7,498 6,659 $ 8,650 $ 9,114 $ 18,125 $ 17,961 2015 Enterprise Mana gement Incentive Share Option Plan The 2015 Enterprise Management Incentive Share Option Plan of Replimune UK (the “2015 Plan”) provided for Replimune UK to grant incentive stock options, non-statutory stock options, stock awards, stock units, stock appreciation rights and other stock-based awards. Incentive stock options were granted under the 2015 Plan only to the Company’s employees, including officers and directors who were also employees. Non-statutory stock options were granted under the 2015 Plan to employees, members of the board of directors, outside advisors and consultants of the Company. 2017 Equity Compensation Plan In July 2017, in conjunction with reorganization by Replimune Limited, pursuant to which each shareholder thereof exchanged their outstanding shares in Replimune Limited for shares in Replimune Group, Inc., on a one-for-one basis (the "Reorganization"), the 2015 Plan was terminated, and all awards were cancelled with replacement awards issued under the 2017 Equity Compensation Plan (the “2017 Plan”). Subsequent to the Reorganization, no additional grants have been or will be made under the 2015 Plan and any outstanding awards under the 2015 Plan have continued, and will continue with their original terms. The Company concluded that the cancellation of the 2015 Plan and issuance of replacement awards under the 2017 Plan was a modification with no change in the material rights and preferences and therefore no recorded change in the fair value of each respective award. The Company’s 2017 Plan provides for the Company to grant incentive stock options or non-statutory stock options, stock awards, stock units, stock appreciation rights and other stock-based awards. Incentive stock options were granted under the 2017 Plan only to the Company’s employees, including officers and directors who were also employees. Restricted stock awards and non-statutory stock options were granted under the 2017 Plan to employees, officers, members of the board of directors, advisors and consultants of the Company. The maximum number of common shares that may be issued under the 2017 Plan was 2,659,885, of which none remained available for future grants as of September 30, 2024. Shares with respect to which awards have expired, terminated, surrendered or cancelled under the 2017 Plan without having been fully exercised will be available for future awards under the 2018 Plan referenced below. In addition, shares of common stock that are tendered to the Company by a participant to exercise an award are added to the number of shares of common stock available for the grant of awards. 2018 Omnibus Incentive Compensation Plan On July 9, 2018, the Company’s board of directors adopted, and the Company’s stockholders approved the 2018 Omnibus Incentive Compensation Plan (the “2018 Plan”), which became effective immediately prior to the effectiveness of the registration statement filed in connection with the Company’s initial public offering. The 2018 Plan provides for the issuance of incentive stock options, non-qualified stock options, stock awards, stock units, stock appreciation rights and other stock-based awards. The number of shares of common stock initially reserved for issuance under the 2018 Plan is 3,617,968 shares. If any options or stock appreciation rights, including outstanding options and stock appreciation rights granted under the 2017 Plan (up to 2,520,247 shares), terminate, expire, or are canceled, forfeited, exchanged, or surrendered without having been exercised, or if any stock awards, stock units or other stock-based awards, including outstanding awards granted under the 2017 Plan, are forfeited, terminated, or otherwise not paid in full in shares of common stock, the shares of the Company’s common stock subject to such grants will be available for purposes of the 2018 Plan. The number of shares reserved for issuance under the 2018 Plan will increase automatically on the first day of each April equal to 4.0% of the total number of shares of common stock outstanding on the last trading day in the immediately preceding fiscal year, which includes for these purposes, the 5,281,616 shares issuable upon exercise of those pre-funded warrants as of March 31, 2024, as described in Note 9 to these consolidated financial statements, or such lesser amount as determined by the Board. On April 1, 2024, the number of shares reserved for issuance under the 2018 Plan automatically increased by 2,667,868 shares pursuant to the terms of the 2018 Plan and based on total number of shares of common stock outstanding on March 31, 2024. As of September 30, 2024, 1,841,705 shares remained available for future grants under the 2018 Plan. The 2015 Plan, the 2017 Plan and the 2018 Plan are administered by the board of directors or, at the discretion of the board of directors, by a committee of the board of directors. However, the board of directors shall administer and approve all grants made to non-employee directors. The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, except that the exercise price per share of incentive stock options may not be less than 100% of the fair market value of the common stock on the date of grant (or 110% of fair value in the case of an award granted to employees who hold more than 10% of the total combined voting power of all classes of stock at the time of grant) and the term of stock options may not be greater than five years for an incentive stock option granted to a 10% stockholder and greater than ten years for all other options granted. Stock options awarded under both plans expire ten years after the grant date, unless the board of directors sets a shorter term. Vesting periods for the plans are determined at the discretion of the board of directors. Incentive stock options granted to employees and non-statutory options granted to employees, officers, members of the board of directors, advisors, and consultants of the Company typically vest over four years. In 2021 the board of directors initiated the award of restricted stock units ("RSUs"), under the 2018 Plan in addition to stock option awards available as part of the Company's equity incentive for employees, officers, advisors and consultants of the Company. The RSUs typically vest over four Employee Stock Purchase Plan On July 9, 2018, the Company’s board of directors adopted and the Company’s stockholders approved the Employee Stock Purchase Plan (the “ESPP”), which became effective immediately prior to the effectiveness of the registration statement that was filed in connection with the Company’s IPO. The total shares of common stock initially reserved for issuance under the ESPP is 348,612 shares. In addition, as of the first trading day of each fiscal year during the term of the ESPP (excluding any extensions), an additional number of shares of the Company’s common stock equal to 1% of the total number of shares outstanding on the last trading day in the immediately preceding fiscal year, which includes for these purposes, the 5,281,616 shares issuable upon exercise of those pre-funded warrants described in Note 9 to these consolidated financial statements, or 697,224 shares, whichever is less (or such lesser amount as determined by the Company’s board of directors) will be added to the number of shares authorized under the ESPP. In accordance with the terms of the ESPP, on April 1, 2024, the number of shares reserved for issuance under the ESPP automatically increased by 666,967, for a total of 3,405,175 shares reserved for the ESPP. If the total number of shares of common stock to be purchased pursuant to outstanding purchase rights on any particular date exceed the number of shares then available for issuance under the ESPP, then the plan administrator will allocate the available shares pro-rata and refund any excess payroll deductions or other contributions to participants. The Company’s ESPP is not currently active. Out-of-Plan Inducement Grants From time to time, the Company grants equity awards to newly hired employees and executives as a material inducement to enter into employment with the Company. The grants constitute "employment inducement grants" in accordance with Rule 5635(c)(4) of the Nasdaq Listing Rules and was issued outside of the 2018 Plan and each of the other stock incentive plans described above. The inducement grants typically include nonqualified stock options to purchase shares of the Company's common stock, as well as restricted stock unit grants representing shares of the Company's common stock. These stock option and restricted stock unit inducement grants have terms and conditions consistent with those set forth under the 2018 Plan and vest under the same respective vesting schedules as stock option and restricted stock unit awards granted under the 2018 Plan. The inducement grants are included in the stock option and RSU award tables below. During the six months ended September 30, 2024 and 2023, the Company granted 75,000 and 125,000 nonqualified stock options to purchase shares of the Company's common stock, and 50,000 and 83,330 restricted stock units under employment inducement grants. Stock option valuation The fair value of stock option grants is estimated using the Black-Scholes option-pricing model. As the Company has limited company-specific historical and implied volatility information, the expected stock volatility is based on a combination of Replimune volatility and the historical volatility of a publicly traded set of peer companies. For options with service-based vesting conditions, the expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to non-employees is equal to the contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. The following table presents, on a weighted-average basis, the assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and directors: Three Months Ended Six Months Ended 2024 2023 2024 2023 Risk-free interest rate 3.72 % 4.34 % 4.37 % 3.69 % Expected term (in years) 6.0 6.1 6.0 6.0 Expected volatility 76.6 % 72.7 % 76.3 % 73.9 % Expected dividend yield 0 % 0 % 0 % 0 % Stock options The following table summarizes the Company’s stock option activity: Number of Weighted Weighted Aggregate Outstanding as of March 31, 2024 8,652,256 $ 16.94 6.61 $ 5,748 Granted 1,929,871 $ 7.95 Exercised (57,144) $ 2.99 Cancelled (292,898) $ 18.66 Outstanding as of September 30, 2024 10,232,085 $ 15.27 6.64 $ 16,026 Options exercisable as of September 30, 2024 6,355,335 $ 16.46 5.29 $ 9,711 Options vested and expected to vest as of September 30, 2024 10,232,085 $ 15.27 6.64 $ 16,026 As of September 30, 2024, there was $31.7 million of unrecognized compensation cost related to unvested common stock options, which is expected to be recognized over a weighted average period of 2.6 years. The weighted average grant-date fair value of stock options granted during the six months ended September 30, 2024 and 2023 was $5.51 and $12.19, respectively. The aggregate intrinsic value of stock options exercised during the six months ended September 30, 2024 was $0.3 million. Restricted and performance stock units In January 2024, the Board approved a one-time PSU award under the 2018 Plan for all employees at the vice president level and below as of January 31, 2024, subject to non-market performance and service conditions. The grants will become vested upon the achievement of the approval of the Company’s first Biologics License Application (“BLA”) for RP1 by the Food and Drug Administration (“FDA”) no later than June 30, 2026. If the Company does not achieve the approval of the Company's first BLA for RP1 before the expiration of June 30, 2026 then no PSU will be earned or vested. The grant date fair value for the PSUs is determined based on the market price of the Company's common stock on the grant date and is recognized over the requisite service period if and when the achievement of such performance condition is determined to be probable by the Company. The Company reassesses the probability of achieving the performance condition at each reporting period. As of September 30, 2024, the Company has not recognized any expense related to PSUs. A summary of the changes in the Company's RSUs and PSUs during the six months ended September 30, 2024 is as follows: Number of Restricted Shares Weighted Outstanding as of March 31, 2024 2,397,890 17.97 Granted 1,788,812 8.02 Vested (514,177) 21.84 Cancelled (175,871) 13.99 Outstanding as of September 30, 2024 3,496,654 $ 12.51 As of September 30, 2024, there was $32.6 million of unrecognized compensation cost related to unvested restricted stock units, which is expected to be recognized over a weighted average period of 2.7 years. Of the $32.6 million of total unrecognized compensation cost, performance based awards tied to the achievement of a company milestone account for approximately $4.8 million. The performance based awards will vest upon achievement of the performance milestone. The remaining unrecognized compensation cost is related to restricted stock units which vest over time.

Net loss per share

Net loss per share	6 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Net loss per share	Net loss per share Basic and diluted net loss per share attributable to common stockholders was calculated as follows: Three Months Ended September 30, Six Months Ended September 30, 2024 2023 2024 2023 Numerator: Net loss $ (53,055) $ (60,044) $ (106,827) $ (109,599) Denominator: Weighted average common shares outstanding, basic and diluted 78,570,135 66,582,280 73,903,650 66,475,577 Net loss per share, basic and diluted $ (0.68) $ (0.90) $ (1.45) $ (1.65) The 10,211,969 shares of the Company's common stock issuable upon exercise of pre-funded warrants described in Note 9 to these consolidated financial statements are included as outstanding common stock in the calculation of basic and diluted net loss per share. The Company’s potentially dilutive securities, which include stock options, unvested restricted and performance stock units and warrants to purchase shares of common stock that resulted from the conversion of warrants to purchase shares of series seed preferred stock existing before the Company's IPO, 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 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 for the periods indicated because including them would have had an anti-dilutive effect: Three and Six Months Ended September 30, 2024 2023 Options to purchase common stock 10,232,085 9,155,387 Unvested restricted and performance stock units 3,496,654 2,189,837 Warrants to purchase common stock 497,344 497,344 14,226,083 11,842,568

Significant agreements

Significant agreements	6 Months Ended
	Sep. 30, 2024
Significant agreements
Significant agreements	Significant agreements Agreement with Bristol-Myers Squibb Company In February 2018, the Company entered into an agreement with Bristol-Myers Squibb Company (“BMS”). Pursuant to the agreement, BMS will provide to the Company, at no cost, a compound for use in the Company’s ongoing clinical trial of RP1. Under the agreement, the Company will sponsor, fund and conduct the clinical trial in accordance with an agreed-upon protocol. BMS granted the Company a non-exclusive, non-transferrable, royalty-free license (with a right to sublicense) under its intellectual property to its compound in the clinical trial and agreed to supply its compound, at no cost to the Company, for use in the clinical trial. In January 2020, this agreement was expanded to cover an additional cohort of 125 patients with anti-PD-1 failed melanoma. Unless earlier terminated, the agreement will remain in effect until (i) the completion of the clinical trial, (ii) all related clinical trial data have been delivered to both parties and (iii) the completion of any statistical analyses and bioanalyses contemplated by the clinical trial protocol or any analysis otherwise agreed upon by the parties. The agreement may be terminated by either party (x) in the event of an uncured material breach by the other party, (y) in the event the other party is insolvent or in bankruptcy proceedings or (z) for safety reasons. Upon termination, the licenses granted to the Company to use BMS’s compound in the clinical trial will terminate. In April 2019, the Company entered into a separate agreement with BMS on terms similar to the terms set forth in the agreement described above, pursuant to which BMS will provide to the Company, at no cost, nivolumab for use in the Company’s Phase 1 clinical trial of RP2 in combination with nivolumab. Agreement with Regeneron Pharmaceuticals, Inc . In May 2018, the Company entered into an agreement with Regeneron Pharmaceuticals, Inc. (“Regeneron”). Pursuant to the agreement the Company agreed to undertake one or more clinical trials with Regeneron for the administration of the Company's product candidates in combination with cemiplimab, an anti-PD-1 therapy developed by Regeneron, across multiple solid tumor types. The first of which, agreed in June 2018, is the Company's ongoing clinical trial testing RP1 in combination with cemiplimab versus cemiplimab alone in patients with CSCC. Each clinical trial will be conducted pursuant to an agreed study plan which, among other things, will identify the name of the sponsor and which party will manage the particular study, and include the protocol, the budget and a schedule of clinical obligations. Pursuant to the terms of the agreement, each party granted the other party a non-exclusive license of their respective intellectual property and agreed to contribute the necessary resources needed to fulfill their respective obligations, in each case, under the terms of agreed study plans. The Company does not expect any further reimbursements from Regeneron related to the initial study plan of June 2018 and the CERPASS trial. The agreement contains representations, warranties, undertakings and indemnities customary for a transaction of this nature. The agreement also contains certain time-based covenants that restrict the Company from entering into a third-party arrangement with respect to the use of its product candidates in combination with an anti-PD-1 therapy and that restrict Regeneron from entering into a third-party arrangement with respect to the use of cemiplimab in combination with an HSV-1 virus, in each case, for the treatment of a tumor type that is the subject of a clinical trial to which the covenants apply. Unless otherwise mutually agreed in a future study plan, these covenants are only applicable to the Company's ongoing Phase 2 clinical trial in CSCC. The agreement may be terminated by either party if (i) there is no active study plan for which a final study report has not been completed and the parties have not entered into a study plan for an additional clinical trial within a period of time after the delivery of the most recent final study report or (ii) in the event of a material breach The agreement with Regeneron is accounted for under ASC 808, Collaborative Arrangements (“ASC 808”), as both parties are active participants and each party pays its own compound costs and share equally in development costs. The Company accounts for costs incurred as part of the study, including costs to supply compounds for use in the study, as research and development expenses within the consolidated statement of operations. The Company recognizes any amounts received from Regeneron in connection with this agreement as an offset to research and development expense within the consolidated statement of operations. In July 2022, Regeneron informed the Company that the costs of the study have reached the initial budget for the initial study plan of June 2018 and that Regeneron's reimbursement of CERPASS study costs to the Company have completed in the period ending June 30, 2022 in relation to the initial study budget. As a result of this notice from, and the ongoing communications with, Regeneron, the Company has not recorded any cost-sharing reimbursements from Regeneron in prepaid expenses and other current assets in the consolidated balance sheet or as an offset to research and development expense within the consolidated statement of operations since Regeneron informed it that Regeneron’s reimbursement of CERPASS study costs have completed. The Company does not expect any further reimbursements from Regeneron related to the initial study plan of June 2018. Roche In December 2022, the Company entered into a Master Clinical Trial Collaboration and Supply Agreement with Roche in relation to the Company's RP2 and RP3 programs in colorectal cancer, or CRC, and hepatocellular carcinoma, or HCC. Under the agreement, the companies intended to collaborate in 30 patient cohort signal finding studies in third-line, or 3L, CRC and in first- and second-line, or 1L and 2L, respectively, HCC. Following the Company's re-prioritization of its product development portfolio in December 2023, the Company has agreed with Roche to terminate the CRC collaboration and pursue the 2L cohort in HCC with RP2 only. Roche has expressed its intent to continue to supply its currently approved drugs, atezolizumab and bevacizumab for the 2L cohort in HCC but is unlikely to share costs following the Company's re-prioritization. The Company is in discussions with Roche about revising these agreements following the Company's changes to its RP2 and RP3 development plans. Under the terms of the initial agreement the Company retained the responsibility of operating the clinical trials as well as retaining all the rights to the development and commercialization of its product candidates. The agreement may be terminated by either party upon sixty days prior written notice to the other party. The agreement with Roche is accounted for under ASC 808, Collaborative Arrangements (“ASC 808”), as both parties are active participants and each party pays its own compound costs. The Company accounts for costs incurred as part of the study, including costs to supply compounds for use in the study, as research and development expenses within the consolidated statement of operations. The Company will recognize any amounts received from Roche in connection with this agreement as an offset to research and development expense within the consolidated statement of operations. During the three and six months ended September 30, 2024 and 2023, the Company did not make any payments to Roche under the terms of the agreement. The Company did not record any costs as an offset to research and development expenses during the three and six months ended September 30, 2024. The Company recorded $1.0 million and $1.7 million as an offset to research and development expenses during the three and six months ended September 30, 2023, respectively. During the six months ended September 30, 2024 and 2023, the Company received payments under the terms of the agreement from Roche of $1.8 million and $0.9 million, respectively. As of September 30, 2024 and March 31, 2024, the Company recorded $0.0 million and $1.8 million as receivables from Roche in connection with this agreement, respectively. Incyte In July 2023, the Company entered into a Clinical Trial Collaboration and Supply Agreement with Incyte Corporation, or Incyte. Under the agreement, the companies will collaborate in a signal finding study in which Incyte will initiate and sponsor a clinical trial of INCB99280 (oral PD-L1 inhibitor) and RP1 in approximately 40 patients with unresectable, high risk CSCC in the neoadjuvant setting. Under the terms of the agreement, the Company will supply Incyte with RP1 for the study and share costs of the study equally with Incyte. The agreement may be terminated by either party upon (i) a material breach not reasonably cured within thirty (30) days; (ii) the discontinuation of development of its clinical drug candidate; (iii) the unethical or illegal business practices of the other party; or (iv) if the parties have not agreed on the protocol or budget within ninety (90) days of the effective date of the agreement. In addition, the Company may terminate the agreement upon the inappropriate or unsafe use of the RP1 product candidate. On July 30, 2024, Incyte announced it has discontinued further development of its oral small molecule PD-L1 inhibitor, which was the intended study drug in the Company's planned collaboration with Incyte. On August 1, 2024, the Company received notice of termination of the Clinical Trial Collaboration and Supply Agreement from Incyte. During the year ended March 31, 2024, the Company did not make any payments to, or receive any payments from, Inctye under the terms of the agreement. Additionally, no costs were recorded to research and development expenses during the three and six months ended September 30, 2024 related to this agreement. Amgen In August 2023 the Company entered into a Settlement Agreement with Amgen and mutually agreed to terminate the Company's challenges to Amgen's patents. In connection with the Settlement Agreement, the Company entered into a License and Covenant Agreement with Amgen in which the Company agreed to pay Amgen low single-digit royalty payments on net sales of its products that, but for the license, could be found to infringe a valid Amgen patent on a country-by-country and product-by-product basis.

Collaboration and other arrange

Collaboration and other arrangements	6 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration and other arrangements	Significant agreements Agreement with Bristol-Myers Squibb Company In February 2018, the Company entered into an agreement with Bristol-Myers Squibb Company (“BMS”). Pursuant to the agreement, BMS will provide to the Company, at no cost, a compound for use in the Company’s ongoing clinical trial of RP1. Under the agreement, the Company will sponsor, fund and conduct the clinical trial in accordance with an agreed-upon protocol. BMS granted the Company a non-exclusive, non-transferrable, royalty-free license (with a right to sublicense) under its intellectual property to its compound in the clinical trial and agreed to supply its compound, at no cost to the Company, for use in the clinical trial. In January 2020, this agreement was expanded to cover an additional cohort of 125 patients with anti-PD-1 failed melanoma. Unless earlier terminated, the agreement will remain in effect until (i) the completion of the clinical trial, (ii) all related clinical trial data have been delivered to both parties and (iii) the completion of any statistical analyses and bioanalyses contemplated by the clinical trial protocol or any analysis otherwise agreed upon by the parties. The agreement may be terminated by either party (x) in the event of an uncured material breach by the other party, (y) in the event the other party is insolvent or in bankruptcy proceedings or (z) for safety reasons. Upon termination, the licenses granted to the Company to use BMS’s compound in the clinical trial will terminate. In April 2019, the Company entered into a separate agreement with BMS on terms similar to the terms set forth in the agreement described above, pursuant to which BMS will provide to the Company, at no cost, nivolumab for use in the Company’s Phase 1 clinical trial of RP2 in combination with nivolumab. Agreement with Regeneron Pharmaceuticals, Inc . In May 2018, the Company entered into an agreement with Regeneron Pharmaceuticals, Inc. (“Regeneron”). Pursuant to the agreement the Company agreed to undertake one or more clinical trials with Regeneron for the administration of the Company's product candidates in combination with cemiplimab, an anti-PD-1 therapy developed by Regeneron, across multiple solid tumor types. The first of which, agreed in June 2018, is the Company's ongoing clinical trial testing RP1 in combination with cemiplimab versus cemiplimab alone in patients with CSCC. Each clinical trial will be conducted pursuant to an agreed study plan which, among other things, will identify the name of the sponsor and which party will manage the particular study, and include the protocol, the budget and a schedule of clinical obligations. Pursuant to the terms of the agreement, each party granted the other party a non-exclusive license of their respective intellectual property and agreed to contribute the necessary resources needed to fulfill their respective obligations, in each case, under the terms of agreed study plans. The Company does not expect any further reimbursements from Regeneron related to the initial study plan of June 2018 and the CERPASS trial. The agreement contains representations, warranties, undertakings and indemnities customary for a transaction of this nature. The agreement also contains certain time-based covenants that restrict the Company from entering into a third-party arrangement with respect to the use of its product candidates in combination with an anti-PD-1 therapy and that restrict Regeneron from entering into a third-party arrangement with respect to the use of cemiplimab in combination with an HSV-1 virus, in each case, for the treatment of a tumor type that is the subject of a clinical trial to which the covenants apply. Unless otherwise mutually agreed in a future study plan, these covenants are only applicable to the Company's ongoing Phase 2 clinical trial in CSCC. The agreement may be terminated by either party if (i) there is no active study plan for which a final study report has not been completed and the parties have not entered into a study plan for an additional clinical trial within a period of time after the delivery of the most recent final study report or (ii) in the event of a material breach The agreement with Regeneron is accounted for under ASC 808, Collaborative Arrangements (“ASC 808”), as both parties are active participants and each party pays its own compound costs and share equally in development costs. The Company accounts for costs incurred as part of the study, including costs to supply compounds for use in the study, as research and development expenses within the consolidated statement of operations. The Company recognizes any amounts received from Regeneron in connection with this agreement as an offset to research and development expense within the consolidated statement of operations. In July 2022, Regeneron informed the Company that the costs of the study have reached the initial budget for the initial study plan of June 2018 and that Regeneron's reimbursement of CERPASS study costs to the Company have completed in the period ending June 30, 2022 in relation to the initial study budget. As a result of this notice from, and the ongoing communications with, Regeneron, the Company has not recorded any cost-sharing reimbursements from Regeneron in prepaid expenses and other current assets in the consolidated balance sheet or as an offset to research and development expense within the consolidated statement of operations since Regeneron informed it that Regeneron’s reimbursement of CERPASS study costs have completed. The Company does not expect any further reimbursements from Regeneron related to the initial study plan of June 2018. Roche In December 2022, the Company entered into a Master Clinical Trial Collaboration and Supply Agreement with Roche in relation to the Company's RP2 and RP3 programs in colorectal cancer, or CRC, and hepatocellular carcinoma, or HCC. Under the agreement, the companies intended to collaborate in 30 patient cohort signal finding studies in third-line, or 3L, CRC and in first- and second-line, or 1L and 2L, respectively, HCC. Following the Company's re-prioritization of its product development portfolio in December 2023, the Company has agreed with Roche to terminate the CRC collaboration and pursue the 2L cohort in HCC with RP2 only. Roche has expressed its intent to continue to supply its currently approved drugs, atezolizumab and bevacizumab for the 2L cohort in HCC but is unlikely to share costs following the Company's re-prioritization. The Company is in discussions with Roche about revising these agreements following the Company's changes to its RP2 and RP3 development plans. Under the terms of the initial agreement the Company retained the responsibility of operating the clinical trials as well as retaining all the rights to the development and commercialization of its product candidates. The agreement may be terminated by either party upon sixty days prior written notice to the other party. The agreement with Roche is accounted for under ASC 808, Collaborative Arrangements (“ASC 808”), as both parties are active participants and each party pays its own compound costs. The Company accounts for costs incurred as part of the study, including costs to supply compounds for use in the study, as research and development expenses within the consolidated statement of operations. The Company will recognize any amounts received from Roche in connection with this agreement as an offset to research and development expense within the consolidated statement of operations. During the three and six months ended September 30, 2024 and 2023, the Company did not make any payments to Roche under the terms of the agreement. The Company did not record any costs as an offset to research and development expenses during the three and six months ended September 30, 2024. The Company recorded $1.0 million and $1.7 million as an offset to research and development expenses during the three and six months ended September 30, 2023, respectively. During the six months ended September 30, 2024 and 2023, the Company received payments under the terms of the agreement from Roche of $1.8 million and $0.9 million, respectively. As of September 30, 2024 and March 31, 2024, the Company recorded $0.0 million and $1.8 million as receivables from Roche in connection with this agreement, respectively. Incyte In July 2023, the Company entered into a Clinical Trial Collaboration and Supply Agreement with Incyte Corporation, or Incyte. Under the agreement, the companies will collaborate in a signal finding study in which Incyte will initiate and sponsor a clinical trial of INCB99280 (oral PD-L1 inhibitor) and RP1 in approximately 40 patients with unresectable, high risk CSCC in the neoadjuvant setting. Under the terms of the agreement, the Company will supply Incyte with RP1 for the study and share costs of the study equally with Incyte. The agreement may be terminated by either party upon (i) a material breach not reasonably cured within thirty (30) days; (ii) the discontinuation of development of its clinical drug candidate; (iii) the unethical or illegal business practices of the other party; or (iv) if the parties have not agreed on the protocol or budget within ninety (90) days of the effective date of the agreement. In addition, the Company may terminate the agreement upon the inappropriate or unsafe use of the RP1 product candidate. On July 30, 2024, Incyte announced it has discontinued further development of its oral small molecule PD-L1 inhibitor, which was the intended study drug in the Company's planned collaboration with Incyte. On August 1, 2024, the Company received notice of termination of the Clinical Trial Collaboration and Supply Agreement from Incyte. During the year ended March 31, 2024, the Company did not make any payments to, or receive any payments from, Inctye under the terms of the agreement. Additionally, no costs were recorded to research and development expenses during the three and six months ended September 30, 2024 related to this agreement. Amgen In August 2023 the Company entered into a Settlement Agreement with Amgen and mutually agreed to terminate the Company's challenges to Amgen's patents. In connection with the Settlement Agreement, the Company entered into a License and Covenant Agreement with Amgen in which the Company agreed to pay Amgen low single-digit royalty payments on net sales of its products that, but for the license, could be found to infringe a valid Amgen patent on a country-by-country and product-by-product basis.

Commitments and contingencies

Commitments and contingencies	6 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies Leases The table below presents the lease-related costs which are included in the consolidated statements of operations for the three months ended September 30, 2024 and 2023: Three Months Ended September 30, Six Months Ended September 30, 2024 2023 2024 2023 Lease cost Finance lease costs: Amortization of right-to-use asset $ 607 $ 607 $ 1,214 $ 1,214 Interest on lease liabilities 531 542 1,065 1,086 Operating lease costs 285 281 566 561 Total lease cost $ 1,423 $ 1,430 $ 2,845 $ 2,861 The following table summarizes the classification of lease costs in the consolidated statement of operations for the three months ended September 30, 2024 and 2023 as follows: Three Months Ended September 30, Six Months Ended September 30, 2024 2023 2024 2023 Finance Lease Costs Research and development $ 607 $ 607 $ 1,214 $ 1,214 Other income (expense) 531 542 1,065 1,086 Operating Lease Costs Research and development 229 228 458 457 Selling, general and administrative 56 53 108 104 Total lease cost $ 1,423 $ 1,430 $ 2,845 $ 2,861 The following table summarizes the maturity of the Company's lease liabilities on an undiscounted cash flow basis by fiscal year and a reconciliation to the operating and financing lease liabilities recognized on its balance sheet as of September 30, 2024: September 30, 2024 Operating leases Financing lease Total 2025 (remaining six months) $ 599 $ 1,376 $ 1,975 2026 1,203 2,799 4,002 2027 1,167 2,883 4,050 2028 1,112 2,969 4,081 2029 1,025 3,058 4,083 Thereafter 966 31,995 32,961 Total lease payments 6,072 45,080 51,152 Less: interest 1,371 19,229 20,600 Total lease liabilities $ 4,701 $ 25,851 $ 30,552 The following table provides lease disclosure as of September 30, 2024 and March 31, 2024: September 30, 2024 March 31, 2024 Leases Right-to-use operating lease asset $ 4,417 $ 4,635 Right-to-use finance lease asset 36,022 37,237 Total lease assets $ 40,439 $ 41,872 Operating lease liabilities, current $ 1,199 $ 1,161 Finance lease liabilities, current 2,758 2,718 Operating lease liabilities, non-current 3,502 3,771 Finance lease liabilities, non-current 23,093 23,410 Total lease liabilities $ 30,552 $ 31,060 The following table provides lease disclosure for the three months ended September 30, 2024 and 2023: Six Months Ended September 30, 2024 2023 Other information Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 583 $ 528 Operating cash flows from finance leases $ 1,065 $ 1,086 Financing cash flows from finance leases $ 277 $ 217 Right-to-use asset obtained in exchange for new operating lease liabilities $ — $ — Weighted-average remaining lease term - operating leases 5.2 years 6.1 years Weighted-average remaining lease term - financing leases 14.8 years 15.8 years Weighted-average discount rate - operating leases 10.4 % 10.2 % Weighted-average discount rate - financing leases 8.3 % 8.3 % The variable lease costs and short-term lease costs were insignificant for the three and six months ended September 30, 2024 and 2023. Manufacturing commitments The Company has entered into an agreement with a contract manufacturing organization to provide clinical trial products. As of September 30, 2024 and March 31, 2024, the Company had committed to minimum payments under these arrangements totaling $0.9 million and $0.9 million, respectively. 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 executive management team and its board of directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements, and therefore it has not accrued any liabilities related to such obligations in its consolidated financial statements as of September 30, 2024 or March 31, 2024. Legal proceedings The Company is not a party to any litigation and does not have contingency reserves established for any litigation liabilities.

Income taxes

Income taxes	6 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income taxes	Income taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company's tax returns. Deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.

Geographic information

Geographic information	6 Months Ended
	Sep. 30, 2024
Segments, Geographical Areas [Abstract]
Geographic information	Geographic information The Company operates in two geographic regions: the United States (Massachusetts) and the United Kingdom (Oxfordshire). Information about the Company’s long-lived assets held in different geographic regions is presented in the tables below: September 30, 2024 March 31, 2024 United States $ 11,555 $ 8,992 United Kingdom 1,036 1,491 $ 12,591 $ 10,483

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net loss	$ (53,055)	$ (53,772)	$ (60,044)	$ (49,555)	$ (106,827)	$ (109,599)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	6 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Principles of consolidation	The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and include the accounts of the Company and its direct and indirect wholly owned subsidiaries, Replimune UK, Replimune US, Replimune Securities Corporation and Replimune (Ireland) Limited after elimination of all intercompany accounts and transactions.
Use of estimates	The preparation of 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 consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual for research and development expenses and the valuation of stock-based awards. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances.
Unaudited interim financial information	The accompanying consolidated balance sheet as of September 30, 2024, the consolidated statements of operations, of comprehensive loss and of stockholders’ equity for the three and six months ended September 30, 2024 and 2023 and the consolidated statements of cash flows for the six months ended September 30, 2024 and 2023 are unaudited. The unaudited interim 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 presentation of the Company’s financial position as of September 30, 2024 and the results of its operations for the three and six months ended September 30, 2024 and 2023 and its cash flows for the six months ended September 30, 2024 and 2023. The financial data and other information disclosed in these consolidated notes related to the three and six months ended September 30, 2024 and 2023 are unaudited. The results for the three and six months ended September 30, 2024 are not necessarily indicative of results to be expected for the year ending March 31, 2025, 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 March 31, 2024, which was filed with the Securities and Exchange Commission on May 16, 2024 (the "Annual Report"). During the three and six months ended September 30, 2024, there have been no changes to the Company’s significant accounting policies as described in the Annual Report.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update ("ASU") No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” This ASU updates income tax disclosure requirements primarily by requiring specific categories and greater disaggregation within the rate reconciliation and disaggregation of income taxes paid by jurisdiction. This ASU is effective for annual periods beginning after December 15, 2024 and is applicable to the Company’s fiscal year beginning April 1, 2025, with early application permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures. In November 2023, the FASB issued ASU 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures". The amendments in this update expand segment disclosure requirements, including new segment disclosure requirements for entities with a single reportable segment among other disclosure requirements. This update is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. The Company is currently evaluating the potential impact of this adoption on the consolidated financial statements and related disclosures. In November 2024, the FASB issued an ASU to require more detailed information about specified categories of expenses (purchases of inventory, employee compensation, depreciation, amortization, and depletion) included in certain expense captions presented on the face of the income statement. This ASU is effective for fiscal years beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. The amendments may be applied either (1) prospectively to financial statements issued for reporting periods after the effective date of this ASU or (2) retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and related disclosures.

Fair value of financial asset_2

Fair value of financial assets and liabilities (Tables)	6 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Schedule of company's financial assets and liabilities measured at fair value on a recurring basis	The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements as of Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ — $ 23,549 $ — $ 23,549 Short-term investments US Government Agency bonds — 119,628 — 119,628 US Treasury bonds — 198,937 — 198,937 $ — $ 342,114 $ — $ 342,114 Fair Value Measurements as of Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ — $ 41,077 $ — $ 41,077 Short-term investments US Government Agency bonds — 199,821 — 199,821 US Treasury bonds — 146,390 — 146,390 $ — $ 387,288 $ — $ 387,288

Short-term investments (Tables)

Short-term investments (Tables)	6 Months Ended
	Sep. 30, 2024
Short-Term Investments [Abstract]
Schedule of short-term investments	As of September 30, 2024 and March 31, 2024, the Company's available-for-sale investments by type consisted of the following: September 30, 2024 Amortized Gross unrealized Gross unrealized Credit Losses Fair value US Government agency bonds $ 119,416 $ 213 $ (1) $ — $ 119,628 US Treasury bonds 198,144 794 (1) — 198,937 Total $ 317,560 $ 1,007 $ (2) $ — $ 318,565 March 31, 2024 Amortized cost Gross unrealized gains Gross unrealized losses Credit Losses Fair value US Government agency bonds 199,905 33 (117) $ — 199,821 US Treasury bonds 146,417 11 (38) — 146,390 Total $ 346,322 $ 44 $ (155) $ — $ 346,211

Property, plant and equipment_2

Property, plant and equipment, net (Tables)	6 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Schedule of property, plant and equipment, net	Property, plant and equipment, net consisted of the following: September 30, 2024 March 31, 2024 Office equipment $ 1,487 $ 1,464 Computer equipment 2,108 1,975 Plant and laboratory equipment 10,747 10,423 Leasehold improvements 1,853 1,886 Capitalized software 6,441 3,515 Construction in progress 1,513 1,117 Total property, plant and equipment 24,149 20,380 Less: Accumulated depreciation (11,558) (9,897) Property, plant and equipment, net $ 12,591 $ 10,483

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	6 Months Ended
	Sep. 30, 2024
Accrued Liabilities and Other Liabilities [Abstract]
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following: September 30, 2024 March 31, 2024 Accrued research and development costs $ 16,410 $ 16,376 Accrued compensation and benefits costs 9,684 13,906 Accrued professional fees 516 369 Other 4,813 3,330 Total accrued expenses and other current liabilities $ 31,423 $ 33,981

Debt (Tables)

Debt (Tables)	6 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Schedule of long-term debt	The summary of obligations under the term loan as of September 30, 2024 and March 31, 2024 consisted of the following (in thousands): September 30, 2024 March 31, 2024 Principal loan balance $ 46,099 $ 45,749 Facility charge and diligence fee (236) (266) Unamortized issuance costs (1,058) (1,191) Accumulated end of term fee 767 517 Long term debt, net $ 45,572 $ 44,809
Schedule of maturities of long-term debt	The annual principal payments due under the Loan Agreement as of fiscal September 30, 2024 and March 31, 2024 were as follows: September 30, 2024 March 31, 2024 2025 — — 2026 — — 2027 20,145 20,145 2028 27,769 27,769 Total $ 47,914 $ 47,914

Stockholders' equity (Tables)

Stockholders' equity (Tables)	6 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Schedule of stockholders equity	The Company had reserved for common stock for the exercise of outstanding stock options and the vesting of restricted stock units, the number of shares remaining available for grant under the Company’s 2018 Omnibus Incentive Compensation Plan and the Company’s Employee Stock Purchase Plan (see Note 10) and the exercise of the outstanding warrants to purchase shares of common stock as follows: September 30, 2024 March 31, 2024 Stock options, issued and outstanding 10,232,085 8,652,256 Restricted and performance stock units 3,496,654 2,397,890 Stock options and restricted stock units, future issuance 1,841,705 2,284,141 Employee stock purchase plan, available for future grants 3,405,175 2,738,208 Pre-IPO warrants to purchase common stock 497,344 497,344 Pre-funded warrants 10,211,969 5,281,616 Total shares of common stock reserved for future issuance 29,684,932 21,851,455

Stock-based compensation (Table

Stock-based compensation (Tables)	6 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of stock-based compensation expense	Stock-based compensation expense was classified in the consolidated statements of operations as follows: Three Months Ended Six Months Ended 2024 2023 2024 2023 Research and development $ 4,078 $ 4,447 $ 8,304 $ 7,745 Selling, general and administrative 4,572 4,667 9,821 10,216 $ 8,650 $ 9,114 $ 18,125 $ 17,961 The following table summarizes stock-based compensation expense by award type for the three and six months ended September 30, 2024 and 2023: Three Months Ended Six Months Ended September 30, 2024 2023 2024 2023 Stock options $ 4,894 $ 5,688 $ 10,627 $ 11,302 Restricted and performance stock units 3,756 3,426 7,498 6,659 $ 8,650 $ 9,114 $ 18,125 $ 17,961
Schedule of assumptions used to determine the grant-date fair value of stock options granted	The following table presents, on a weighted-average basis, the assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and directors: Three Months Ended Six Months Ended 2024 2023 2024 2023 Risk-free interest rate 3.72 % 4.34 % 4.37 % 3.69 % Expected term (in years) 6.0 6.1 6.0 6.0 Expected volatility 76.6 % 72.7 % 76.3 % 73.9 % Expected dividend yield 0 % 0 % 0 % 0 %
Schedule of of stock option activity	The following table summarizes the Company’s stock option activity: Number of Weighted Weighted Aggregate Outstanding as of March 31, 2024 8,652,256 $ 16.94 6.61 $ 5,748 Granted 1,929,871 $ 7.95 Exercised (57,144) $ 2.99 Cancelled (292,898) $ 18.66 Outstanding as of September 30, 2024 10,232,085 $ 15.27 6.64 $ 16,026 Options exercisable as of September 30, 2024 6,355,335 $ 16.46 5.29 $ 9,711 Options vested and expected to vest as of September 30, 2024 10,232,085 $ 15.27 6.64 $ 16,026
Schedule of share-based payment arrangement, restricted stock and restricted stock unit, activity	A summary of the changes in the Company's RSUs and PSUs during the six months ended September 30, 2024 is as follows: Number of Restricted Shares Weighted Outstanding as of March 31, 2024 2,397,890 17.97 Granted 1,788,812 8.02 Vested (514,177) 21.84 Cancelled (175,871) 13.99 Outstanding as of September 30, 2024 3,496,654 $ 12.51

Net loss per share (Tables)

Net loss per share (Tables)	6 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Schedule of calculation of basic and diluted net loss per share attributable to common stockholders	Basic and diluted net loss per share attributable to common stockholders was calculated as follows: Three Months Ended September 30, Six Months Ended September 30, 2024 2023 2024 2023 Numerator: Net loss $ (53,055) $ (60,044) $ (106,827) $ (109,599) Denominator: Weighted average common shares outstanding, basic and diluted 78,570,135 66,582,280 73,903,650 66,475,577 Net loss per share, basic and diluted $ (0.68) $ (0.90) $ (1.45) $ (1.65)
Schedule of anti-dilutive securities excluded from the computation of diluted net loss per share attributable to common shareholders	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 for the periods indicated because including them would have had an anti-dilutive effect: Three and Six Months Ended September 30, 2024 2023 Options to purchase common stock 10,232,085 9,155,387 Unvested restricted and performance stock units 3,496,654 2,189,837 Warrants to purchase common stock 497,344 497,344 14,226,083 11,842,568

Commitments and contingencies (

Commitments and contingencies (Tables)	6 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule of variable lease components	The table below presents the lease-related costs which are included in the consolidated statements of operations for the three months ended September 30, 2024 and 2023: Three Months Ended September 30, Six Months Ended September 30, 2024 2023 2024 2023 Lease cost Finance lease costs: Amortization of right-to-use asset $ 607 $ 607 $ 1,214 $ 1,214 Interest on lease liabilities 531 542 1,065 1,086 Operating lease costs 285 281 566 561 Total lease cost $ 1,423 $ 1,430 $ 2,845 $ 2,861 The following table summarizes the classification of lease costs in the consolidated statement of operations for the three months ended September 30, 2024 and 2023 as follows: Three Months Ended September 30, Six Months Ended September 30, 2024 2023 2024 2023 Finance Lease Costs Research and development $ 607 $ 607 $ 1,214 $ 1,214 Other income (expense) 531 542 1,065 1,086 Operating Lease Costs Research and development 229 228 458 457 Selling, general and administrative 56 53 108 104 Total lease cost $ 1,423 $ 1,430 $ 2,845 $ 2,861 The following table provides lease disclosure for the three months ended September 30, 2024 and 2023: Six Months Ended September 30, 2024 2023 Other information Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 583 $ 528 Operating cash flows from finance leases $ 1,065 $ 1,086 Financing cash flows from finance leases $ 277 $ 217 Right-to-use asset obtained in exchange for new operating lease liabilities $ — $ — Weighted-average remaining lease term - operating leases 5.2 years 6.1 years Weighted-average remaining lease term - financing leases 14.8 years 15.8 years Weighted-average discount rate - operating leases 10.4 % 10.2 % Weighted-average discount rate - financing leases 8.3 % 8.3 %
Schedule of the maturity of company's lease liabilities	The following table summarizes the maturity of the Company's lease liabilities on an undiscounted cash flow basis by fiscal year and a reconciliation to the operating and financing lease liabilities recognized on its balance sheet as of September 30, 2024: September 30, 2024 Operating leases Financing lease Total 2025 (remaining six months) $ 599 $ 1,376 $ 1,975 2026 1,203 2,799 4,002 2027 1,167 2,883 4,050 2028 1,112 2,969 4,081 2029 1,025 3,058 4,083 Thereafter 966 31,995 32,961 Total lease payments 6,072 45,080 51,152 Less: interest 1,371 19,229 20,600 Total lease liabilities $ 4,701 $ 25,851 $ 30,552
Schedule of additional information related to leases	The following table provides lease disclosure as of September 30, 2024 and March 31, 2024: September 30, 2024 March 31, 2024 Leases Right-to-use operating lease asset $ 4,417 $ 4,635 Right-to-use finance lease asset 36,022 37,237 Total lease assets $ 40,439 $ 41,872 Operating lease liabilities, current $ 1,199 $ 1,161 Finance lease liabilities, current 2,758 2,718 Operating lease liabilities, non-current 3,502 3,771 Finance lease liabilities, non-current 23,093 23,410 Total lease liabilities $ 30,552 $ 31,060

Geographic information (Tables)

Geographic information (Tables)	6 Months Ended
	Sep. 30, 2024
Segments, Geographical Areas [Abstract]
Schedule of company's long-lived assets held in different geographic regions	The Company operates in two geographic regions: the United States (Massachusetts) and the United Kingdom (Oxfordshire). Information about the Company’s long-lived assets held in different geographic regions is presented in the tables below: September 30, 2024 March 31, 2024 United States $ 11,555 $ 8,992 United Kingdom 1,036 1,491 $ 12,591 $ 10,483

Nature of the business (Details

Nature of the business (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ 53,055	$ 53,772	$ 60,044	$ 49,555	$ 106,827	$ 109,599
Accumulated deficit	$ 808,109				$ 808,109		$ 701,282

Fair value of financial asset_3

Fair value of financial assets and liabilities (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2024	Mar. 31, 2024
Fair value of financial assets and liabilities
Short-term investments	$ 342,114	$ 387,288
Money market funds
Fair value of financial assets and liabilities
Cash equivalents	23,549	41,077
US Government Agency bonds
Fair value of financial assets and liabilities
Short-term investments	119,628	199,821
US Treasury bonds
Fair value of financial assets and liabilities
Short-term investments	198,937	146,390
Level 1
Fair value of financial assets and liabilities
Short-term investments	0	0
Level 1 | Money market funds
Fair value of financial assets and liabilities
Cash equivalents	0	0
Level 1 | US Government Agency bonds
Fair value of financial assets and liabilities
Short-term investments	0	0
Level 1 | US Treasury bonds
Fair value of financial assets and liabilities
Short-term investments	0	0
Level 2
Fair value of financial assets and liabilities
Short-term investments	342,114	387,288
Level 2 | Money market funds
Fair value of financial assets and liabilities
Cash equivalents	23,549	41,077
Level 2 | US Government Agency bonds
Fair value of financial assets and liabilities
Short-term investments	119,628	199,821
Level 2 | US Treasury bonds
Fair value of financial assets and liabilities
Short-term investments	198,937	146,390
Level 3
Fair value of financial assets and liabilities
Short-term investments	0	0
Level 3 | Money market funds
Fair value of financial assets and liabilities
Cash equivalents	0	0
Level 3 | US Government Agency bonds
Fair value of financial assets and liabilities
Short-term investments	0	0
Level 3 | US Treasury bonds
Fair value of financial assets and liabilities
Short-term investments	$ 0	$ 0

Short-term investments (Details

Short-term investments (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Sep. 30, 2024	Mar. 31, 2024
US Government Agency bonds
Short-term investments
Amortized cost	$ 119,416	$ 199,905
Gross unrealized gains	213	33
Gross unrealized losses	(1)	(117)
Credit Losses	0	0
Fair value	119,628	199,821
US Treasury bonds
Short-term investments
Amortized cost	198,144	146,417
Gross unrealized gains	794	11
Gross unrealized losses	(1)	(38)
Credit Losses	0	0
Fair value	198,937	146,390
Short-term investments
Short-term investments
Amortized cost	317,560	346,322
Gross unrealized gains	1,007	44
Gross unrealized losses	(2)	(155)
Credit Losses	0	0
Fair value	$ 318,565	$ 346,211

Property, plant and equipment_3

Property, plant and equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Mar. 31, 2024
Property, plant and equipment, net
Property, plant and equipment , gross	$ 24,149		$ 24,149		$ 20,380
Less: Accumulated depreciation	(11,558)		(11,558)		(9,897)
Property, plant and equipment, net	12,591		12,591		10,483
Depreciation and amortization expense	900	$ 700	1,661	$ 1,275
Amortization on capitalized software	100		100
Office equipment
Property, plant and equipment, net
Property, plant and equipment , gross	1,487		1,487		1,464
Computer equipment
Property, plant and equipment, net
Property, plant and equipment , gross	2,108		2,108		1,975
Plant and laboratory equipment
Property, plant and equipment, net
Property, plant and equipment , gross	10,747		10,747		10,423
Leasehold improvements
Property, plant and equipment, net
Property, plant and equipment , gross	1,853		1,853		1,886
Capitalized software
Property, plant and equipment, net
Property, plant and equipment , gross	6,441		6,441		3,515
Construction in progress
Property, plant and equipment, net
Property, plant and equipment , gross	$ 1,513		$ 1,513		$ 1,117

Accrued expenses and other cu_3

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Mar. 31, 2024
Accrued Liabilities and Other Liabilities [Abstract]
Accrued research and development costs	$ 16,410	$ 16,376
Accrued compensation and benefits costs	9,684	13,906
Accrued professional fees	516	369
Other	4,813	3,330
Total accrued expenses and other current liabilities	$ 31,423	$ 33,981

Debt - Narrative (Details)

Debt - Narrative (Details)			3 Months Ended		6 Months Ended
	Jun. 28, 2023 USD ($)	Oct. 06, 2022 USD ($) advance	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Mar. 31, 2024 USD ($)	Dec. 22, 2023 USD ($)
Debt Instrument [Line Items]
Unrestricted cash percentage			35%		35%
Interest expense			$ 1,438,000	$ 955,000	$ 2,864,000	$ 2,070,000
Secured Debt | Line of Credit | Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 200,000,000
Variable rate (as a percent)		7.25%
Additional rate (as a percent)		1.75%
Stated interest rate (as a percent)		1.50%
Prepayment fee, first 12 months (as a percent)		3%
Prepayment fee, After first 12 months before 36 months (as a percent)		2%
Prepayment fee, after 36 months (as a percent)		1%
Maximum amount outstanding for covenant		$ 100,000,000
Minimum market capitalization		$ 1,200,000,000
Minimum restricted cash (as a percent)		50%
Minimum unrestricted cash (as a percent)		85%
Facility charge		$ 500,000
Payment of issuance costs		$ 1,500,000
Repayment Fee (as a percent)		4.95%
Accrued for final payment on debt			800,000		800,000		$ 500,000
Unamortized deferred financing costs			1,100,000		1,100,000		$ 1,200,000
Interest expense			$ 1,400,000	$ 1,000,000	$ 2,900,000	$ 2,100,000
Secured Debt | Line of Credit | Term Loan Facility | Maximum
Debt Instrument [Line Items]
Variable rate (as a percent)		7.25%
Secured Debt | Line of Credit | Term Loan Facility, Tranche One
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 30,000,000
Secured Debt | Line of Credit | Term Loan Facility, Tranche Two
Debt Instrument [Line Items]
Maximum borrowing capacity		30,000,000						$ 15,000,000
Secured Debt | Line of Credit | Term Loan Facility, Tranche Three
Debt Instrument [Line Items]
Maximum borrowing capacity		115,000,000
Secured Debt | Line of Credit | Term Loan Facility, Tranche Four
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 25,000,000
Number of term loan advances | advance		2
Secured Debt | Line of Credit | Term Loan Facility, Tranche Five
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 25,000,000
Number of term loan advances | advance		2
Secured Debt | Line of Credit | Term Loan Facility, Tranche One and Two
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 60,000,000
Decrease in borrowing capacity	$ 30,000,000

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - Secured Debt - Line of Credit - Term Loan Facility - USD ($) $ in Thousands	Sep. 30, 2024	Mar. 31, 2024
Debt Instrument [Line Items]
Principal loan balance	$ 46,099	$ 45,749
Facility charge and diligence fee	(236)	(266)
Unamortized issuance costs	(1,058)	(1,191)
Accumulated end of term fee	767	517
Long term debt, net	$ 45,572	$ 44,809

Debt - Schedule of Maturity of

Debt - Schedule of Maturity of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Mar. 31, 2024
Debt Instrument [Line Items]
End of term charge	$ 2,200
Line of Credit | Term Loan Facility | Secured Debt
Debt Instrument [Line Items]
2025	0	$ 0
2026	0	0
2027	20,145	20,145
2028	27,769	27,769
Total	$ 47,914	$ 47,914

Stockholders' equity - Common S

Stockholders' equity - Common Stock and Undesignated Preferred Stock (Details) - $ / shares	Sep. 30, 2024	Mar. 31, 2024
Stockholders' Equity Note [Abstract]
Common stock, authorized (in shares)	150,000,000	150,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Undesignated preferred stock, authorized (in shares)	10,000,000
Preferred stock, Par Value (in dollars per share)	$ 0.001
Undesignated preferred shares issued (in shares)	0

Stockholders' equity - Schedule

Stockholders' equity - Schedule of Pre-funded Warrants (Details) - shares	Sep. 30, 2024	Mar. 31, 2024
Stock options, issued and outstanding
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	10,232,085	8,652,256
Restricted and performance stock units
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	3,496,654	2,397,890
Stock options and restricted stock units, future issuance
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	1,841,705	2,284,141
Employee stock purchase plan, available for future grants
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	3,405,175	2,738,208
Pre-IPO warrants to purchase common stock
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	497,344	497,344
Pre-funded warrants
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	10,211,969	5,281,616
Total shares of common stock reserved for future issuance
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	29,684,932	21,851,455

Stockholders' equity - ATM Prog

Stockholders' equity - ATM Program (Details) - USD ($) $ / shares in Units, $ in Millions	Aug. 03, 2023	Sep. 30, 2024	Mar. 31, 2024
Class of Warrant or Right [Line Items]
Common stock, par value (in dollars per share)		$ 0.001	$ 0.001
ATM Program
Class of Warrant or Right [Line Items]
Percentage of commission	3%
ATM Program | Common stock
Class of Warrant or Right [Line Items]
Maximum received on transaction	$ 100
Common stock, par value (in dollars per share)	$ 0.001

Stockholders' equity - Equity o

Stockholders' equity - Equity offerings (Details) $ / shares in Units, $ in Millions	Jun. 14, 2024 USD ($) $ / shares shares
Class of Warrant or Right [Line Items]
Number of shares issued (in shares) | shares	5,668,937
Price per share (in dollars per share) | $ / shares	$ 8.82
Net proceeds | $	$ 96.7
2024 Pre-funded Warrants
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares) | shares	5,669,578
Share price (in dollars per share) | $ / shares	$ 8.819
Underwriter rights
Class of Warrant or Right [Line Items]
Underwriting discounts, commissions and other offering expenses | $	$ 3.3

Pre-funded Warrants - Narrative

Pre-funded Warrants - Narrative (Details) - $ / shares	1 Months Ended	6 Months Ended
	Oct. 31, 2020	Sep. 30, 2024	Mar. 31, 2024	Jul. 09, 2018
Class of Warrant or Right [Line Items]
Number of stock warrants issued (in shares)				10,211,969
Pre-funded warrants
Class of Warrant or Right [Line Items]
Number of stock warrants issued (in shares)		739,225
Exercise price (in dollars per share)		$ 0.001
Common stock
Class of Warrant or Right [Line Items]
Shares issued during period (in shares)		739,225
Pre-funded warrants
Class of Warrant or Right [Line Items]
Maximum percentage of holding for exercise warrants (as a percent)	9.99%
Maximum percentage of increase (decrease) of holding for exercise warrants (as a percent)	19.99%
Prior notice period to change percentage of holding (in days)	61 days
Issuance of pre-funded warrants (in shares)		10,211,969	5,281,616

Stock-based compensation - Clas

Stock-based compensation - Classification of expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation
Stock-based compensation expense	$ 8,650	$ 9,114	$ 18,125	$ 17,961
Stock options
Share-Based Compensation
Stock-based compensation expense	4,894	5,688	10,627	11,302
Restricted and performance stock units
Share-Based Compensation
Stock-based compensation expense	3,756	3,426	7,498	6,659
Research and development
Share-Based Compensation
Stock-based compensation expense	4,078	4,447	8,304	7,745
Selling, general and administrative
Share-Based Compensation
Stock-based compensation expense	$ 4,572	$ 4,667	$ 9,821	$ 10,216

Stock-based compensation - Addi

Stock-based compensation - Additional Information (Details) $ / shares in Units, $ in Millions			6 Months Ended
	Apr. 01, 2024 shares	Jul. 09, 2018 shares	Sep. 30, 2024 USD ($) $ / shares shares	Sep. 30, 2023 $ / shares shares	Jul. 31, 2017
Stock-Based Compensation
Conversion ratio					1
Total unrecognized compensation cost | $			$ 32.6
Expenses expected to be recognized over a weighted average remaining period			2 years 8 months 12 days
Weighted average grant-date fair value per share of stock options granted | $ / shares			$ 5.51	$ 12.19
Value of stock options exercised | $			$ 0.3
2017 Plan
Stock-Based Compensation
Shares authorized (in shares)			2,659,885
Number of shares available for grant		2,520,247	0
2018 Plan
Stock-Based Compensation
Shares authorized (in shares)		3,617,968
Number of shares available for grant			1,841,705
Share based payment award percentage of outstanding shares		4%
Additional shares authorized (in shares)	2,667,868
2018 Plan | Pre-funded warrants
Stock-Based Compensation
Common stock reserved for issuance (in shares)		5,281,616
ESPP
Stock-Based Compensation
Share based payment award percentage of outstanding shares		1%
Common stock reserved for issuance (in shares)	3,405,175	348,612
Additional shares authorized (in shares)	666,967	697,224
Stock options
Stock-Based Compensation
Exercise price for persons holding ten percent of voting power (as a percent)			100%
Exercise price for persons holding more than ten percent of voting power (as a percent)			110%
Share based payment award expiration period			10 years
Share based payment award vesting period			4 years
Total unrecognized compensation cost | $			$ 31.7
Expenses expected to be recognized over a weighted average remaining period			2 years 7 months 6 days
Stock options | Maximum
Stock-Based Compensation
Expiration period for persons holding ten percent of voting power			5 years
Stock options | Minimum
Stock-Based Compensation
Expiration period for persons holding more than ten percent of voting power			10 years
RSUs
Stock-Based Compensation
Share based payment award vesting period			4 years
RSUs | Out Of Plan Inducement Grants
Stock-Based Compensation
Stock unit grant (in shares)			50,000	83,330
PSUs
Stock-Based Compensation
Total unrecognized compensation cost | $			$ 4.8
PSUs | 2018 Plan
Stock-Based Compensation
Stock unit grant (in shares)			246,110
Nonqualified Stock Options | Out Of Plan Inducement Grants
Stock-Based Compensation
Stock unit grant (in shares)			75,000	125,000

Stock-based compensation - Assu

Stock-based compensation - Assumptions to determine grant-date fair value of stock options (Details) - Stock options	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Stock-Based Compensation
Risk-free interest rate	3.72%	4.34%	4.37%	3.69%
Expected term (in years)	6 years	6 years 1 month 6 days	6 years	6 years
Expected volatility	76.60%	72.70%	76.30%	73.90%
Expected dividend yield	0%	0%	0%	0%

Stock-based compensation - Stoc

Stock-based compensation - Stock option activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) $ / shares shares
Number of Shares
Outstanding at beginning of the period (in shares) | shares	8,652,256
Granted (in shares) | shares	1,929,871
Exercised (in shares) | shares	(57,144)
Cancelled (in shares) | shares	(292,898)
Outstanding at end of the period (in shares) | shares	10,232,085	8,652,256
Options exercisable (in shares) | shares	6,355,335
Options vested and expected to vest (in shares) | shares	10,232,085
Weighted Average Exercise Price
Outstanding at beginning of the period (in dollars per share) | $ / shares	$ 16.94
Granted (in dollars per share) | $ / shares	7.95
Exercised (in dollars per share) | $ / shares	2.99
Cancelled (in dollars per share) | $ / shares	18.66
Outstanding at end of the period (in dollars per share) | $ / shares	15.27	$ 16.94
Options exercisable (in dollars per share) | $ / shares	16.46
Options vested and expected to vest (in dollars per share) | $ / shares	$ 15.27
Weighted Average Contractual Term (Years)
Outstanding (years)	6 years 7 months 20 days	6 years 7 months 9 days
Options exercisable (years)	5 years 3 months 14 days
Options vested and expected to vest (years)	6 years 7 months 20 days
Aggregate Intrinsic Value
Outstanding | $	$ 16,026	$ 5,748
Options exercisable | $	9,711
Options vested and expected to vest | $	$ 16,026

Stock-based compensation - Summ

Stock-based compensation - Summary of RSU Activity (Details) $ / shares in Units, $ in Millions	6 Months Ended
	Sep. 30, 2024 USD ($) $ / shares shares
Weighted Average Grant Date Fair Value
Total unrecognized compensation cost | $	$ 32.6
Expenses expected to be recognized over a weighted average remaining period	2 years 8 months 12 days
Restricted and performance stock units
Number of Restricted Shares
Outstanding as of March 31, 2024 | shares	2,397,890
Granted (in shares) | shares	1,788,812
Vested (in shares) | shares	(514,177)
Cancelled (in shares) | shares	(175,871)
Outstanding as of September 30, 2024 | shares	3,496,654
Weighted Average Grant Date Fair Value
Outstanding as of March 31, 2024 (in dollars per share) | $ / shares	$ 17.97
Granted (in dollars per share) | $ / shares	8.02
Vested (in dollars per share) | $ / shares	21.84
Cancelled (in dollars per share) | $ / shares	13.99
Outstanding as of September 30, 2024 (in dollars per share) | $ / shares	$ 12.51

Net loss per share - Computatio

Net loss per share - Computation of Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net loss	$ (53,055)	$ (60,044)	$ (106,827)	$ (109,599)
Denominator:
Weighted average common shares outstanding, basic (in shares)	78,570,135	66,582,280	73,903,650	66,475,577
Weighted average common shares outstanding, diluted (in shares)	78,570,135	66,582,280	73,903,650	66,475,577
Net loss per share, basic (in dollars per share)	$ (0.68)	$ (0.90)	$ (1.45)	$ (1.65)
Net loss per share, diluted (in dollars per share)	$ (0.68)	$ (0.90)	$ (1.45)	$ (1.65)

Net loss per share - Narrative

Net loss per share - Narrative (Details)	Jul. 09, 2018 shares
Earnings Per Share [Abstract]
Number of stock warrants issued (in shares)	10,211,969

Net loss per share - Computat_2

Net loss per share - Computation of diluted net loss per share attributable to common stockholders (Details) - shares	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Diluted net loss per share attributable to common stockholders
Antidilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	14,226,083	11,842,568	14,226,083	11,842,568
Options to purchase common stock
Diluted net loss per share attributable to common stockholders
Antidilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	10,232,085	9,155,387	10,232,085	9,155,387
Unvested restricted and performance stock units
Diluted net loss per share attributable to common stockholders
Antidilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	3,496,654	2,189,837	3,496,654	2,189,837
Warrants to purchase common stock
Diluted net loss per share attributable to common stockholders
Antidilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	497,344	497,344	497,344	497,344

Significant agreements (Details

Significant agreements (Details)	1 Months Ended
	Jan. 31, 2020 patient
Bristol-Myers Squibb Company
Significant agreements
Number of patients	125

Collaboration and other arran_2

Collaboration and other arrangements (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Mar. 31, 2024
Master Clinical Trial Collaboration and Supply Agreement - Roche
Significant agreements
Termination period			60 days
Offset to research and development expense	$ 0	$ 1,000,000	$ 0	$ 1,700,000
Payments received			1,800,000	$ 900,000
Receivables	$ 0		$ 0		$ 1,800,000
Clinical Trial Collaboration and Supply Agreement - Incyte | Minimum
Significant agreements
Termination period			30 days
Clinical Trial Collaboration and Supply Agreement - Incyte | Maximum
Significant agreements
Termination period			90 days

Commitments and contingencies -

Commitments and contingencies - Components of lease expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Finance lease costs:
Amortization of right-to-use asset	$ 607	$ 607	$ 1,214	$ 1,214
Interest on lease liabilities	531	542	1,065	1,086
Operating lease costs	285	281	566	561
Total lease cost	$ 1,423	$ 1,430	$ 2,845	$ 2,861

Commitments and contingencies_2

Commitments and contingencies - Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Lessee, Lease, Description [Line Items]
Finance Lease Costs	$ 607	$ 607	$ 1,214	$ 1,214
Interest on lease liabilities	531	542	1,065	1,086
Operating Lease Costs	285	281	566	561
Total lease cost	1,423	1,430	2,845	2,861
Research and development
Lessee, Lease, Description [Line Items]
Finance Lease Costs	607	607	1,214	1,214
Operating Lease Costs	229	228	458	457
Selling, general and administrative
Lessee, Lease, Description [Line Items]
Operating Lease Costs	$ 56	$ 53	$ 108	$ 104

Commitments and contingencies_3

Commitments and contingencies - Balance sheet disclosures (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Operating leases
2025 (remaining six months)	$ 599
2026	1,203
2027	1,167
2028	1,112
2029	1,025
Thereafter	966
Total lease payments	6,072
Less: interest	1,371
Total lease liabilities	4,701
Financing lease
2025 (remaining six months)	1,376
2026	2,799
2027	2,883
2028	2,969
2029	3,058
Thereafter	31,995
Total lease payments	45,080
Less: interest	19,229
Total lease liabilities	25,851
Total
2025 (remaining six months)	1,975
2026	4,002
2027	4,050
2028	4,081
2029	4,083
Thereafter	32,961
Total lease payments	51,152
Less: interest	20,600
Total lease liabilities	$ 30,552

Commitments and contingencies_4

Commitments and contingencies - Other information (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Mar. 31, 2024
Leases
Right-to-use operating lease asset	$ 4,417		$ 4,635
Right-to-use finance lease asset	36,022		37,237
Total lease assets	40,439		41,872
Operating lease liabilities, current	1,199		1,161
Finance lease liabilities, current	2,758		2,718
Operating lease liabilities, non-current	3,502		3,771
Financing lease liabilities, non-current	23,093		23,410
Total lease liabilities	30,552		$ 31,060
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	583	$ 528
Operating cash flows from finance leases	1,065	1,086
Financing cash flows from finance leases	277	217
Right-to-use asset obtained in exchange for new operating lease liabilities	$ 0	$ 0
Weighted-average remaining lease term - operating leases	5 years 2 months 12 days	6 years 1 month 6 days
Weighted-average remaining lease term - financing leases	14 years 9 months 18 days	15 years 9 months 18 days
Weighted-average discount rate - operating leases	10.40%	10.20%
Weighted-average discount rate - financing leases	8.30%	8.30%

Commitments and contingencies_5

Commitments and contingencies - Additional information (Details) - USD ($) $ in Millions	Sep. 30, 2024	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Minimum payments committed to manufacturing organization	$ 0.9	$ 0.9

Geographic information (Details

Geographic information (Details) $ in Thousands	6 Months Ended
	Sep. 30, 2024 USD ($) region	Mar. 31, 2024 USD ($)
Segments, Geographical Areas [Abstract]
Number of operating geographic regions | region	2
Geographic information
Long-lived assets	$ 12,591	$ 10,483
United States
Geographic information
Long-lived assets	11,555	8,992
United Kingdom
Geographic information
Long-lived assets	$ 1,036	$ 1,491