0001737953-22-000010 | 10-K | XBRL Viewer

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Cover Page - USD ($) $ in Millions	12 Months Ended
Cover Page - USD ($) $ in Millions	Mar. 31, 2022	May 16, 2022	Sep. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Mar. 31, 2022
Current Fiscal Year End Date	--03-31
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, 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 Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 620.3
Entity Common Stock, Shares Outstanding		49,069,995
Documents Incorporated by Reference	The registrant intends to file a definitive proxy statement pursuant to Regulation 14A within 120 days of the end of the fiscal year ended March 31, 2022. Portions of such definitive proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0001737953
Amendment Flag	false
Entity Ex Transition Period	true
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY

Audit Information	12 Months Ended
Audit Information	Mar. 31, 2022
Auditor Information [Abstract]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	238

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Current assets:
Cash and cash equivalents	$ 105,948	$ 182,518
Short-term investments	289,707	293,784
Research and development incentives receivable	3,055	2,953
Prepaid expenses and other current assets	5,267	4,492
Total current assets	403,977	483,747
Property, plant and equipment, net	7,933	7,442
Restricted cash	1,636	1,636
Right-to-use asset – operating leases	5,552	5,751
Right-to-use asset – financing leases	42,094	44,522
Total assets	461,192	543,098
Current liabilities:
Accounts payable	3,732	2,355
Accrued expenses and other current liabilities	13,392	8,735
Operating lease liabilities, current	1,070	970
Financing lease liabilities, current	2,562	2,487
Total current liabilities	20,756	14,547
Operating lease liabilities, non-current	4,801	5,078
Financing lease liabilities, non-current	24,406	24,745
Total liabilities	49,963	44,370
Commitments and contingencies (Note 12)
Stockholders’ equity:
Common stock, $0.001 par value; 150,000,000 shares authorized as of March 31, 2022 and March 31, 2021; 47,338,660 and 46,566,481 shares issued and outstanding as of March 31, 2022 and March 31, 2021, respectively	47	47
Additional paid-in capital	723,359	692,243
Accumulated deficit	(311,204)	(193,168)
Accumulated other comprehensive loss	(973)	(394)
Total stockholders’ equity	411,229	498,728
Total liabilities and stockholders’ equity	$ 461,192	$ 543,098

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2022	Mar. 31, 2021
Statement of Financial Position [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)	47,338,660	46,566,481
Common stock, outstanding (in shares)	47,338,660	46,566,481

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 79,545	$ 56,754
Selling, general and administrative	38,769	23,201
Total operating expenses	118,314	79,955
Loss from operations	(118,314)	(79,955)
Other income (expense):
Research and development incentives	3,170	2,807
Investment income	390	916
Interest expense on finance lease liability	(2,223)	(2,242)
Interest expense on debt obligations	0	(818)
Loss on extinguishment of debt	0	(913)
Other (expense) income	(1,059)	(665)
Total other income (expense), net	278	(915)
Net loss	$ (118,036)	$ (80,870)
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (2.26)	$ (1.75)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (2.26)	$ (1.75)
Weighted average common shares outstanding, basic (in shares)	52,212,269	46,248,969
Weighted average common shares outstanding, diluted (in shares)	52,212,269	46,248,969

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net loss	$ (118,036)	$ (80,870)
Other comprehensive loss:
Foreign currency translation gain	748	866
#REF!	(1,327)	(278)
Comprehensive loss	$ (118,615)	$ (80,282)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical)	12 Months Ended
	Mar. 31, 2022 USD ($)
Other comprehensive loss:
Net unrealized (loss) gain on short-term investments, net of tax	$ 0

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, 2020		36,668,743
Balance at Mar. 31, 2020	$ 183,718	$ 37	$ 296,961	$ (112,298)	$ (982)
Increase (decrease) in Stockholders' Equity
Adjustments to Additional Paid in Capital, Warrant Issued	91,650		91,650
Issuance of common stock, net of issuance costs and underwriter fees (in shares)		9,103,261
Issuance of common stock, net of issuance costs and underwriter fees of $18,892	286,107	$ 8	286,099
Foreign currency translation adjustment	866				866
Unrealized gain (loss) on short-term investments, net of tax	(278)				(278)
Exercise of stock options (in shares)		794,477
Exercise of stock options	5,745	$ 2	5,743
Stock-based compensation expense	11,790		11,790
Net loss	(80,870)			(80,870)
Balance (in shares) at Mar. 31, 2021		46,566,481
Balance at Mar. 31, 2021	498,728	$ 47	692,243	(193,168)	(394)
Increase (decrease) in Stockholders' Equity
Foreign currency translation adjustment	748				748
Unrealized gain (loss) on short-term investments, net of tax	$ (1,327)				(1,327)
Exercise of stock options (in shares)	768,186	768,186
Exercise of stock options	$ 6,862	$ 0	6,862
Vesting of restricted stock units (in shares)		3,993
Stock-based compensation expense	24,254		24,254
Net loss	(118,036)			(118,036)
Balance (in shares) at Mar. 31, 2022		47,338,660
Balance at Mar. 31, 2022	$ 411,229	$ 47	$ 723,359	$ (311,204)	$ (973)

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)	12 Months Ended
	Mar. 31, 2021 USD ($)
Prefunded warrants
Issuance costs and underwriter fees	$ 5,850,000
Follow-on public offering
Issuance costs and underwriter fees	$ 18,892,000

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (118,036)	$ (80,870)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	24,254	11,790
Depreciation and amortization	2,147	1,711
Net amortization of premiums and discounts on short-term investments	2,220	1,376
Noncash interest expense	0	181
Loss on extinguishment of debt	0	913
Changes in operating assets and liabilities:
Research and development incentives receivable	(247)	325
Prepaid expenses and other current assets	(815)	(1,707)
Operating lease, right-of-use-asset	99	447
Finance lease, right-of-use-asset	2,428	2,403
Accounts payable	1,118	(1,031)
Accrued expenses and other current liabilities	4,725	3,413
Operating lease liabilities	(73)	(340)
Net cash used in operating activities	(82,180)	(61,389)
Cash flows from investing activities:
Purchases of property, plant and equipment	(2,336)	(2,392)
Purchase of short-term investments	(255,720)	(392,434)
Proceeds from sales and maturities of short-term investments	256,250	206,050
Net cash (used in) investing activities	(1,806)	(188,776)
Cash flows from financing activities:
Proceeds from issuance of common stock in follow-on public offering, net of underwriting fees and discounts	0	286,107
Proceeds from issuance of prefunded warrants to purchase common stock, net of underwriting fees and discounts	0	91,650
Proceeds from exercise of stock options	6,862	5,745
Payment of debt issuance costs	0	(100)
Principal payment of finance lease obligation	(264)	(145)
Principal payment of long-term debt	0	(10,000)
Payment of long-term debt extinguishment costs	0	(795)
Net cash provided by financing activities	6,598	372,462
Effect of exchange rate changes on cash, cash equivalents and restricted cash	818	721
Net (decrease) increase in cash, cash equivalents and restricted cash	(76,570)	123,018
Cash, cash equivalents and restricted cash at beginning of period	184,154	61,136
Cash, cash equivalents and restricted cash at end of period	107,584	184,154
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	0	636
Cash paid for income taxes, net	55	0
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable	415	98
Lease assets obtained in exchange for new operating lease liabilities	$ 363	$ 1,580

Nature of the business	12 Months Ended
Nature of the business	Mar. 31, 2022
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 focused on the development of oncolytic immunotherapies to treat 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, 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 significant revenue from product sales. 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 $118.0 million and $80.9 million for the years ended March 31, 2022 and 2021, respectively. In addition, as of March 31, 2022, the Company had an accumulated deficit of $311.2 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 the consolidated financial statements. Impact of COVID-19 In December 2019, a novel strain of coronavirus, which causes the disease known as COVID-19, was reported to have surfaced in Wuhan, China. Since then, COVID-19 coronavirus has spread globally. In March 2020, the World Health Organization declared the COVID-19 outbreak a pandemic and the U.S. government imposed travel restrictions on travel between the United States, Europe and certain other countries. The impact of this pandemic has been, and will likely continue to be, extensive in many aspects of society, which has resulted, and will likely continue to result, in significant disruption to the global economy as well as businesses and capital markets around the world. In response to public health directives and orders and to help minimize the risk of the virus to employees, the Company has taken precautionary measures including establishing and maintaining an internal COVID-19 task force to ensure timely communication and decision-making in response to COVID-19, establishing work-from home policies and return-to-office policies as well as other measures to respond and adapt to the COVID-19 impact. For those employees working from our offices, laboratories and manufacturing facilities, we have implemented stringent safety measures designed to comply with applicable federal, state and local guidelines instituted in response to the COVID-19 pandemic and we continue to examine our protocols as the pandemic and health guidance evolves. The Company has taken these and other precautionary steps while maintaining business continuity in order to continue to progress its programs. While there has been no prolonged material disruption to the Company’s business to date, the impact of the virus, including work-from-home policies, may negatively impact productivity, disrupt the Company’s business, and delay its preclinical research and clinical trial activities and its development program timelines, the magnitude of which will depend, in part, on the length and severity of the restrictions and other limitations on the Company’s ability to conduct its business in the ordinary course. Other impacts to the Company’s business may include disruptions of its suppliers or material supplies and disruptions or restrictions on its employees’ ability to travel. Any prolonged material disruption to the Company’s employees, suppliers or supply could adversely impact the Company’s preclinical research and clinical trial activities, financial condition and results of operations, including its ability to obtain financing.

Summary of significant accounting policies

12 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

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, or 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.

The full extent to which the COVID-19 pandemic will directly or indirectly impact our business, results of operations and financial condition, including, expenses, research and development costs and employee-related amounts, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain it or treat COVID-19. We have made estimates of the impact of COVID-19 within our financial statements and there may be changes to those estimates in future periods.

Estimates are periodically reviewed in light of reasonable changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates or assumptions.

Foreign currency and currency translation

The functional currency for the Company’s wholly owned foreign subsidiary, Replimune UK, is the British pound. Assets and liabilities of Replimune UK are translated into United States dollars at the exchange rate in effect on the balance sheet date. Revenues and expenses are translated at the average exchange rate in effect during the period. Unrealized translation gains and losses are recorded as a cumulative translation adjustment, which is included in the consolidated statements of stockholders’ equity as a component of accumulated other comprehensive loss. Adjustments that arise from exchange rate changes on transactions denominated in a currency other than the local currency are included in other income (expense), net in the consolidated statements of operations as incurred.

Concentrations of credit risk and of significant suppliers

Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents as well as short-term investments. The Company deposits its cash in financial institutions in amounts that may exceed federally insured limits, and has not experienced any losses on such accounts and does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships.

The Company relies, and expects to continue to rely, on a small number of vendors to manufacture supplies and raw materials for its development programs. These programs could be adversely affected by a significant interruption in these manufacturing services or the availability of raw materials.

Cash and cash equivalents

The Company considers all highly liquid investments with original maturities of three months or less at date of purchase to be cash equivalents. Cash equivalents consisted of money market funds as of March 31, 2022 and 2021, respectively. As of March 31, 2022 and 2021, the amount of cash equivalents included in cash and cash equivalents totaled $75,117 and $150,734, respectively.

Restricted cash

The Company holds restricted cash in segregated bank accounts in connection with a letter of credit. As of March 31, 2022 and 2021, restricted cash consisted of $1,636, held for the benefit of the landlords in connection with our leases. These amounts have been classified as non-current assets on the Company’s consolidated balance sheets.

Short-term investments

The Company’s short-term debt security investments are classified as available-for-sale and are carried at fair value, with the unrealized gains and losses reported as a component of accumulated other comprehensive loss in stockholders’ equity. Realized gains and losses and declines in value determined to be other than temporary are based on the specific identification method and are included as a component of other income (expense), net in the consolidated statements of operations.

The Company evaluates its short-term debt security investments with unrealized losses for other-than-temporary impairment. When assessing short-term debt security investments for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the short-term debt security investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the short-term debt security investment that the Company considers to be “other than temporary,” the Company reduces the short-term debt security investment to fair value through a charge to the consolidated statements of operations. No such adjustments were necessary during the periods presented.

The Company’s short-term investments as of March 31, 2022 and 2021 had maturities of less than two years.

Property, plant and equipment

Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful lives of the respective assets as follows:


			Estimated Useful life
Office equipment			5 years
Computer equipment and software			3 years
Plant, manufacturing and laboratory equipment			5 years
Leasehold improvements			Lesser of lease term or 10 years

Costs for capital assets not yet placed into service are capitalized as construction-in-progress and depreciated in accordance with the above guidelines once placed into service. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in loss from operations. Expenditures for repairs and maintenance are charged to expense as incurred.

Impairment of long-lived assets

Long-lived assets consist of property, plant and equipment. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset group for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset group to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value, determined based on discounted cash flows. To date, the Company has not recorded any impairment losses on long-lived assets.

Fair value measurements

Certain assets and liabilities of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

•Level 1 — Quoted prices in active markets for identical assets or liabilities.

•Level 2 — Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

•Level 3 — Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques.

The Company’s short-term investments and cash equivalents are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). The carrying values of research and development incentives receivable, prepaid expenses and other current assets, accounts payable and accrued expenses and other current liabilities approximate their fair values due to the short-term nature of these assets and liabilities.

Debt issuance costs

Debt issuance costs consist of payments made to secure commitments under certain debt financing arrangements. These amounts are recognized as interest expense over the period of the financing arrangement using the effective interest method. If the financing arrangement is canceled or forfeited, or if the utility of the arrangement to the Company is otherwise compromised, these costs are recognized as interest expense immediately. The Company’s consolidated financial statements present debt issuance costs related to a recognized debt liability as a direct reduction from the carrying amount of that debt liability.

Segment information

The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s current focus is on developing oncolytic immunotherapies for the treatment of cancer.

Research and development costs

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits, facilities costs and laboratory supplies, depreciation and external costs of outside vendors engaged to conduct preclinical development, clinical development activities and clinical trials as well as to manufacture clinical trial materials. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered or the services rendered. Upfront payments for materials and supplies acquired for particular research and development activities that have no alternative future use in other research and development projects or otherwise, and therefore have no separate economic value, are expensed as research and development costs at the time the costs are incurred.

Research contract costs and accruals

The Company has entered into various research and development-related contracts with companies both inside and outside of the United States. These agreements are generally cancellable, and related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or clinical trials, including the phase or completion of

events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.

Patent costs

All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as selling, general and administrative expenses.

Stock-based compensation

The Company accounts for share-based payment awards granted to employees, consultants, and non-employees and directors using the fair value of the Company’s common stock on the grant date and compensation expense is recognized for those awards over the requisite service period, which is generally the vesting period of the respective award. The grant date fair value is utilized for time-vested restricted stock units (“RSUs”) and the fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option, and the Company’s expected dividend yield (see Note 9). Forfeitures are accounted for as they occur. To date, the Company has issued stock-based awards with only service-based vesting conditions and records the expense for these awards using the straight-line method.

The Company classifies stock-based compensation expense in its consolidated statements of operations in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified.

Research and development incentives and receivable

The Company, through its subsidiary in the United Kingdom, receives reimbursements of certain research and development expenditures as part of a United Kingdom government’s research and development tax reliefs program. Under the program, a percentage of qualifying research and development expenses incurred by the Company’s subsidiary in the United Kingdom are reimbursed up to 14.5%.

Management has assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive program described above. At each period end, management estimates the reimbursement available to the Company based on available information at the time.

The Company recognizes income from the research and development incentives when the relevant expenditure has been incurred, the associated conditions have been satisfied and there is reasonable assurance that the reimbursement will be received. The Company records these research and development incentives as other income. The research and development incentives receivable represents an amount due in connection with the above program. The Company recorded other income from research and development incentives of $3,170 and $2,807 during the years ended March 31, 2022 and 2021, respectively, in the consolidated statements of operations and a research and development incentives receivable of $3,055 and $2,953 as of March 31, 2022 and 2021, respectively, on the consolidated balance sheets.

Comprehensive loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders. For the year ended March 31, 2022, comprehensive loss included $748 of foreign currency translation adjustments and $1,327 of unrealized losses on short-term investments, net of tax. For the year ended March 31, 2021, comprehensive loss included $866 of foreign currency translation adjustments and $278 of unrealized losses on short-term investments, net of tax.

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.

Net income (loss) per share

Basic net income (loss) per common share is computed by dividing the net income (loss) by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) per common share is computed by dividing the diluted net income (loss) by the weighted average number of shares of common stock outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents.

In periods in which the Company reports a net loss, diluted net loss per share is the same as basic net loss per share, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.

Recently adopted accounting pronouncements

In December 2019, the Financial Accounting Standards Board ("FASB") issued ASU No. 2019-12 Income Taxes (Topic 740)-Simplifying the Accounting for Income Taxes (ASU 2019-12), which is intended to simplify the accounting for income taxes. ASU 2019-12 removes certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. ASU 2019-12 also amends other aspects of the guidance to help simplify and promote consistent application of GAAP. The new standard was effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. We adopted ASU 2019-12 effective April 1, 2021. The adoption of ASU 2019-12 did not have a material impact on our consolidated financial statements.

Recently issued accounting pronouncements

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326). The standard changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. Financial assets measured at amortized cost will be presented at the net amount expected to be collected by using an allowance for credit losses. In April 2019, the FASB issued ASU No. 2019-4, Codification Improvements to Topic 326, Financial Instruments — Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments, which clarifies and corrects certain unintended applications of the guidance contained in each of the amended Topics. Additionally, in May 2019, the FASB issued ASU No. 2019-5, Financial Instruments — Credit Losses (Topic 326), which provides an option to irrevocably elect to measure certain individual financial assets at fair value instead of amortized cost. The standard is effective for fiscal years and interim periods beginning after December 15, 2022. Early adoption is permitted for all periods beginning after December 15, 2018. The adoption of ASU 2016-13 is not expected to have a material impact on the Company’s consolidated financial statements.

Fair value of financial assets and liabilities

12 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

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 March 31, 2022 Using:
	Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	—	$	75,117	$	—	$	75,117
US Government Agency bonds	—		26,688		—		26,688
US Treasury bonds	—		263,019		—		263,019
	$	—	$	364,824	$	—	$	364,824


	Fair Value Measurements as of March 31, 2021 Using:
	Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	—	$	150,734	$	—	$	150,734
US Government Agency bonds	—		67,012		—		67,012
US Treasury bonds	—		226,772		—		226,772
	$	—	$	444,518	$	—	$	444,518

The underlying securities held in the money market funds held by the Company are all government backed securities. During the years ended March 31, 2022 and 2021, there were no transfers between levels.

Valuation of cash equivalents and short-term investments

Money market funds, U.S. Treasury bonds and U.S. Government Agency 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 March 31, 2022 and March 31, 2021.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Short-term investments

12 Months Ended

Mar. 31, 2022

Short-term Investments [Abstract]

Short-term investments

As of March 31, 2022 and 2021, the Company's available-for-sale investments by type, consisted of the following:


	March 31, 2022
	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
US Government agency bonds	$	26,827	$	—	$	(139)	$	26,688
US Treasury bonds	264,162		—		(1,143)		263,019
	$	290,989	$	—	$	(1,282)	$	289,707


	March 31, 2021
	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
US Government agency bonds	$	67,017	$	12	$	(17)	$	67,012
US Treasury bonds	226,722		55		(5)		226,772
	$	293,739	$	67	$	(22)	$	293,784

As of March 31, 2022 and 2021, available-for-sale securities consisted of investments that mature within one year, with the exception of certain U.S. Government agency bonds and U.S. Treasury bonds which have maturities between one and two years and an aggregate fair value of $7.6 million and $54.2 million, respectively.

Property, plant and equipment, net

12 Months Ended

Mar. 31, 2022

Property, Plant and Equipment [Abstract]

Property, plant and equipment, net

Property, plant and equipment, net consisted of the following:


	March 31, 2022		March 31, 2021

Office equipment	$	937	$	830
Computer equipment	1,667		1,695
Plant and laboratory equipment	7,720		6,369
Leasehold improvements	785		784
Construction in progress	1,619		412
	12,728		10,090
Less: Accumulated depreciation and amortization	(4,795)		(2,648)
	$	7,933	$	7,442

Depreciation and amortization expense was $2.1 million and $1.7 million for the years ended March 31, 2022 and 2021, respectively, and recorded within research and development and selling, general and administrative expenses in the consolidated statement of operations.

Accrued expenses and other current liabilities

12 Months Ended

Mar. 31, 2022

Accrued expenses and other current liabilities

Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following:


	March 31, 2022		March 31, 2021
Accrued research and development costs	$	5,882	$	3,862
Accrued compensation and benefits costs	5,569		3,952
Accrued professional fees	621		407
Other	1,320		514
	$	13,392	$	8,735

Long-term debt	12 Months Ended
Long-term debt	Mar. 31, 2022
Debt Disclosure [Abstract]
Long-term debt	Long-term debt Hercules Loan Agreement On August 8, 2019, (the “Closing Date”) the Company and certain of its affiliates entered into a Loan and Security Agreement (as amended, the “Hercules Loan Agreement”) with Hercules Capital, Inc. (“Hercules”) pursuant to which Hercules agreed to make available to the Company a secured term loan facility in the amount of $30,000 (the “Term Loan Facility”), subject to certain terms and conditions. The Company borrowed $10,000 under the Hercules Loan Agreement in one advance as a single tranche term Loan on the Closing Date upon which the Company paid a $225 facility charge and incurred $130 in additional closing and legal fees. On June 1, 2020, the Company entered into the First Amendment to the Hercules Loan Agreement (the “Hercules First Amendment”), to, among other things, increase the aggregate principal amount of the secured term loan facility from $30,000 to $40,000. Pursuant to the Hercules First Amendment, subject to the achievement of certain milestones, the Company could have borrowed three tranches of up to $10,000 between October 1, 2020 and December 15, 2020, July 1, 2020 and June 30, 2021, and July 1, 2021 and December 15, 2021, respectively. The Company incurred $100 in additional closing and legal fees in connection with Hercules First Amendment which were capitalized and will be amortized as part of the effective yield. On December 15, 2020, the Company entered into a Payoff Letter with respect to the Hercules Loan Agreement, which resulted in a loss on extinguishment of debt of $913 including both cash and non-cash expense. Pursuant to the Payoff Letter, the Company paid a total of $10,839 to Hercules, representing $10,000 in outstanding principal, $495 end of term charge, $300 early termination fee due and $44 in accrued interest owed to Hercules under the Hercules Loan Agreement. In connection with the execution of the Payoff Letter and the repayment of the Company’s outstanding obligations under the Hercules Loan Agreement, the Hercules Loan Agreement and the related loan documents were terminated. The Term Loan Facility was secured by substantially all of the Company’s assets, but excluding its intellectual property, and subject to certain exceptions and exclusions. All liens on the Company’s assets held by Hercules were released in connection with the execution of the Payoff Letter. In connection with entering into the Hercules Loan Agreement the Company paid Hercules $355 and $100 of upfront fees, respectively. Such upfront fees included closing costs and legal fees associated with entering into the respective agreements, and were recorded as a debt discount. The Company recognized aggregate interest expense under the Hercules Loan Agreement of $818 during the year ended March 31, 2021, which included non-cash interest expense of $181. Non-cash interest expense included the amortization of the debt discount of $82 and the accretion of the final payment of $99, respectively. There were no principal payments due or paid under the Hercules Loan Agreement during the year ended March 31, 2022.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (h)
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (d)
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-SubTopic 20
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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-Section 50
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-Subparagraph (i)
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+ Details

Stockholders' equity	12 Months Ended
Stockholders' equity	Mar. 31, 2022
Stockholders' Equity Note [Abstract]
Stockholders' equity	Stockholders’ Equity Common stock As of March 31, 2022 and 2021, 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. As of March 31, 2022 and 2021, the Company had reserved 16,605,804 and 14,572,115 shares of common stock for the exercise of outstanding stock options and the vesting of restricted share 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 9) and the exercise of the outstanding warrants to purchase shares of common, respectively. Undesignated preferred stock As of March 31, 2022, 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 March 31, 2022. ATM program In August 2019, the Company entered into a Sales Agreement (as amended, the “Sales Agreement”) with SVB Leerink LLC (the “Agent”), pursuant to which the Company could sell, from time to time, at its option, up to an aggregate amount of $75,000 of shares of the Company’s common stock, $0.001 par value per share through the Agent, as the Company’s sales agent. In June 2020, the 2019 Sales Agreement was amended to reduce the aggregate offering amount under the 2019 Sales Agreement from $75,000 of shares to $30,000 of shares. On August 11, 2020, the 2019 Sales Agreement was terminated by the execution by the Company and the Agent of a new sales agreement, which was subsequently amended on October 21, 2020 (as amended, the “2020 Sales Agreement”). Under the 2020 Sales Agreement the Company may sell, from time to time, at its option, up to an aggregate of $62,500 of shares of the Company’s common stock, $0.001 par value per share (the “Shares”), through the Agent, as the Company’s sales agent. Any Shares to be offered and sold under the 2020 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 in negotiated transactions, if authorized by the Company, and (ii) pursuant to, and only upon the effectiveness of, a registration statement on Form S-3 filed by the Company with the Securities and Exchange Commission on August 11, 2020 for an offering of up to $350,000 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 2020 Sales Agreement, the 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 cannot provide any assurances that it will issue any additional Shares pursuant to the 2020 Sales Agreement. The Company will pay the 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 Agent with customary indemnification rights. The Company did not issue or sell any shares under the 2020 Sales Agreement during the year ended March 31, 2022. For additional information, see Note 17 to these consolidated financial statements. Equity offerings In November 2019, pursuant to an underwriting agreement (the “November 2019 Underwriting Agreement”) with J.P. Morgan Securities LLC and SVB Leerink LLC, as representatives of the several underwriters named therein (the “November 2019 Underwriters”), the Company issued and sold to the November 2019 Underwriters (a) 4,516,561 shares of the Company’s common stock (the “November 2019 Shares”), inclusive of the November 2019 Underwriters partially exercised 30-day option and purchased an additional 838,530 shares of the Company’s common stock, and (b) pre-funded warrants to purchase 2,200,000 shares of the Company’s common stock (the “November 2019 Pre-Funded Warrants”). The November 2019 shares were sold to the November 2019 Underwriters (the “November 2019 Offering”) at the public offering price of $13.61 per share and the pre-funded warrants were sold at a public offering price of $13.6099 per November 2019 Pre-Funded Warrant, which represented the per share public offering price for November 2019 Shares less a $0.0001 per share exercise price for each such November 2019 Pre-Funded Warrant. The Company received aggregate net proceeds of approximately $85,598 in the November 2019 Offering, after deducting underwriting discounts, commissions and other offering expenses payable by the Company of approximately $5,814. Funds affiliated with Redmile Group, LLC purchased all of the November 2019 Pre-Funded Warrants. The November 2019 Pre-Funded Warrants are exercisable at any time after the date of issuance. A holder of November 2019 Pre-Funded Warrants may not exercise the November 2019 Pre-Funded Warrant if the 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. In June 2020, pursuant to an underwriting agreement (the “June 2020 Underwriting Agreement”) with J.P. Morgan Securities LLC and SVB Leerink LLC, as representatives of the several underwriters named therein (“the June 2020 Underwriters”), the Company sold to the June 2020 Underwriters (a) 3,478,261 shares of the Company’s common stock (the “June 2020 Shares”), inclusive of the underwrites 30-day option to purchase up to an additional 652,173 shares of the Company’s commons stock, and (b) pre-funded warrants to purchase 1,521,738 shares of the Company’s common stock (the “June 2020 Pre-Funded Warrants”).The June 2020 Shares of the Company’s common stock were sold to the June 2020 Underwriters at the public offering price of $23.00 per share and the June 2020 Pre-Funded Warrants were sold at a public offering price of $22.9999 per June 2020 Pre-Funded Warrant, which represented the per share public offering price for the June 2020 shares less a $0.0001 per share exercise price for each such June 2020 Pre-Funded Warrant. The Company received aggregate net proceeds of approximately $107,782 after deducting underwriting discounts, commissions and other offering expenses payable by the Company of approximately $7,217. Funds affiliated with Redmile Group, LLC and funds affiliated with a second institutional investor purchased all of the June 2020 Pre-Funded Warrants. The June 2020 Pre-Funded Warrants are exercisable at any time after the date of issuance. A holder of June 2020 Pre-Funded Warrants may not exercise the June 2020 Pre-Funded Warrants if the 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 June 2020 Pre-Funded Warrants may increase or decrease this percentage up to 19.99% by providing at least 61 days’ prior notice to the Company. In October 2020, pursuant to an underwriting agreement with J.P. Morgan Securities LLC and SVB Leerink LLC, as representatives of the several underwriters named therein, the Company issued and sold to the underwriters (a) 5,625,000 shares of the Company’s common stock, inclusive of the underwriters 30-day option to purchase up to an additional 937,500 shares of the Company’s common stock, and (b) pre-funded warrants to purchase 1,562,500 shares of the Company’s common stock (the “October 2020 Pre-Funded Warrants”). The shares of the Company’s common stock were sold to the underwriters at the public offering price of $40.00 per share and the pre-funded warrants were sold at a public offering price of $39.9999 per October 2020 Pre-Funded Warrant, which represented the per share public offering price for the Company’s common stock less a $0.0001 per share exercise price for each such pre-funded warrant. The Company received aggregate net proceeds of approximately $269,975 after deducting underwriting discounts, commissions and other offering expenses payable by the Company of approximately $17,525. Funds affiliated with Redmile Group, LLC and funds affiliated with a second institutional investor purchased all of the October 2020 Pre-Funded Warrants. The October 2020 Pre-Funded Warrants are exercisable at any time after the date of issuance. A holder of October 2020 Pre-Funded Warrants may not exercise the October 2020 Pre-Funded Warrants if the 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 October 2020 Pre-Funded Warrants may increase or decrease this percentage up to 19.99% by providing at least 61 days’ prior notice to the Company. Other than as set forth in Note 9 and Note 10 to these consolidated financial statements, the 5,284,238 Pre-Funded Warrants are not included in the number of issued and outstanding shares of the Company’s common stock set forth herein. As of March 31, 2022, none of the November 2019 Pre-Funded Warrants, the June 2020 Pre-Funded Warrants, or the October 2020 Pre-Funded Warrants had been exercised.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stock-based compensation

12 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Stock-based compensation

Stock-based compensation expense

The following table summarizes the classification of stock-based compensation expense in the consolidated statements of operations for the years ended March 31, 2022 and 2021 as follows:


	Twelve Months Ended March 31,
	2022		2021
Research and development	$	8,568	$	5,749
Selling, general and administrative	15,686		6,041
	$	24,254	$	11,790

The following table summarizes stock-based compensation expense by award type for the years ended March 31, 2022 and 2021 as follows:


	Twelve Months Ended March 31,
	2022		2021
Stock options	$	19,160	$	11,778
Restricted stock units	5,094		12
	$	24,254	$	11,790

2015 Enterprise Management 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 are granted only to the Company’s employees, including officers and directors who are also employees. Non-statutory stock options are granted 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 March 31, 2022. 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 for 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 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 our 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 Company stock outstanding on the last trading day in the immediately preceding fiscal year, which includes for these purposes, the number of shares issuable upon exercise of the November 2019 Pre-Funded Warrants, the June 2020 Pre-Funded Warrants, and the October 2020 Pre-Funded Warrants, or such lesser amount as determined by the Board. On April 1, 2021, the number of shares reserved for issuance under the 2018 Plan automatically increased by 2,074,028 shares pursuant to the terms of the 2018 Plan and based on total number of shares of Company stock outstanding on March 31, 2021. On April 1, 2020, the number of shares reserved for issuance under the 2018 Plan automatically increased by 1,466,749 shares pursuant to the terms of the 2018 Plan. As of March 31, 2022, 1,933,300 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 both 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 approximately equal annual installments with the first such installment occurring on a designated vesting date that is approximately on the one year anniversary date of the date of grant and the subsequent installments occurring on the subsequent three annual anniversaries of the designated vesting date.

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 for the Company’s IPO. The total shares of common stock initially reserved for issuance under the ESPP is limited to 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 number of shares issuable upon exercise of the November 2019 Pre-Funded Warrants, the June 2020 Pre-Funded Warrants, and the October 2020 Pre-Funded Warrants, 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, 2021 and 2020, the number of shares reserved for issuance under the ESPP automatically increased by 518,507 and 366,687 shares, respectively, for a total of 1,550,375 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 Grant

In May 2021, the Company granted an equity award to a newly hired executive as a material inducement to enter into employment with the Company. The grant constitutes an "employment inducement grant" 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 grant included a nonqualified stock option to purchase up to 125,000 shares of the Company's common stock, as well as a restricted stock unit grant representing 88,333 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 grant is included in the stock option and RSU award tables below.

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:


	Twelve Months Ended March 31,
	2022		2021
Risk-free interest rate	1.18	%	0.93	%
Expected term (in years)	6.0		6.3
Expected volatility	79.8	%	75.4	%
Expected dividend yield	0	%	0	%

Stock options

A summary of stock option activity under the Company’s equity incentive plans for the year ended March 31, 2022 is as follows:


	Number of Shares	Weighted Average Exercise Price		Weighted Average Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding as of March 31, 2021	6,460,184	$	13.26	7.95	$	116,193
Granted	1,573,862	31.29
Exercised	(768,186)	8.93
Cancelled	(751,526)	24.93
Outstanding as of March 31, 2022	6,514,334	16.78		7.26	$	30,358
Options exercisable as of March 31, 2021	2,698,708	$	8.38	6.79	$	59,717
Options exercisable as of March 31, 2022	3,645,749	$	10.85	6.31	$	24,875

As of March 31, 2022, there was $37.9 million of unrecognized compensation cost related to unvested common stock options, which is expected to be recognized over a weighted average period of 2.51 years.

The weighted average grant-date fair value of stock options granted during the years ended March 31, 2022 and 2021 was $21.40 and $12.03, respectively. The aggregate intrinsic value of stock options exercised during the years ended March 31, 2022 and 2021 was $16.2 million and $24.9 million, respectively.

Restricted stock units

A summary of the changes in the Company’s RSUs during the year ended March 31, 2022 is as follows:


	Number of Restricted Shares	Weighted Average Grant Date Fair Value
Outstanding as of March 31, 2021	15,975	$	34.15
Granted	868,016	31.37
Vested	(3,993)	34.15
Cancelled	(53,785)	31.95
Outstanding as of March 31, 2022	826,213	$	31.38

At March 31, 2022, there was $21.0 million of total unrecognized compensation cost related to unvested RSUs, which will be recognized over a weighted-average period of 3.3 years.

Net loss per share

12 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Net loss per share

The following table sets forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders (in thousands, except per share amounts):


	Twelve Months Ended March 31,
	2022		2021
Numerator:
Net loss	$	(118,036)	$	(80,870)
Denominator:
Weighted average common shares outstanding, basic and diluted	52,212,269		46,248,969
Net loss per share, basic and diluted	$	(2.26)	$	(1.75)

The November 2019 Pre-Funded Warrants, the June 2020 Pre-Funded Warrants and October 2020 Pre-Funded Warrants 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 and warrants to purchase common stock 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:


	Twelve Months Ended March 31,
	2022	2021
Options to purchase common stock	6,514,334	6,476,159
Warrants to purchase common stock	497,344	497,344
	7,011,678	6,973,503

Significant agreements	12 Months Ended
Significant agreements	Mar. 31, 2022
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”). The Company and Regeneron are each independently developing compounds for the treatment of certain tumor types. Pursuant to the agreement, the Company and Regeneron will undertake one or more clinical trials using a combination of the compounds being developed by each entity. Under the agreement, each study will be conducted under terms set out in a separately agreed upon study plan that will identify the name of the sponsor and which party will manage the particular clinical trial, and include the protocol, the budget and a schedule of clinical obligations. In June 2018, under the terms of the agreement between the Company and Regeneron, the parties agreed to the first study plan. The Company and Regeneron have agreed to the protocol, budget, sample testing and clinical obligations schedule under the study plan. Development and supply costs associated with the study plan will be split equally between the Company and Regeneron. Pursuant to the terms of the agreement, each party granted the other party a non-exclusive license under its respective intellectual property and agreed to contribute the necessary resources needed to fulfill its respective obligations, in each case, under the terms of the agreed-upon or to-be agreed upon study plans. Development costs of a particular clinical trial will be split equally between the Company and Regeneron in accordance with the agreed upon study plan. 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 will account 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 Regeneron in connection with this agreement as an offset to research and development expense within the consolidated statement of operations. Under the terms of the agreement, on a quarterly basis the Company and Regeneron true-up costs of the study and make corresponding payments to the party that incurred the majority of the costs. During the years ended March 31, 2022 and 2021, the Company did not make any payments under the terms of the agreement to Regeneron. During the years ended March 31, 2022 and 2021, the Company received payments under the terms of the agreement from Regeneron of $6.1 million and $5.1 million, respectively. As of March 31, 2022 and 2021, the Company recorded $2.0 million and $1.3 million of receivables from Regeneron in connection with this agreement in prepaid expenses and other current assets in the consolidated balance sheet, respectively.

Commitments and contingencies

12 Months Ended

Mar. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

Commitments and contingencies

Leases

The Company leases real estate assets and equipment, and determination if an arrangement is a lease occurs at inception. For leases with terms greater than 12 months, the Company records a related right-of-use (“ROU”) asset and lease liability at the present value of lease payments over the term. Many leases include fixed rental escalation clauses, renewal options and/or termination options that are factored into the determination of lease payments when appropriate. The Company’s leases do not provide an implicit rate, and thus the Company estimated the incremental borrowing rate in calculating the present value of the lease payments. The Company has elected not to record a ROU asset and lease obligation for short-term leases (with terms less than 12 months) or separate non-lease components from associated lease components for its real estate lease assets. As a result, all contract consideration is allocated to the single lease component.

In October 2021, the Company entered into an agreement to lease approximately 2,951 square feet of research and development, office and laboratory space in Abingdon, Oxfordshire, United Kingdom. Pursuant to the lease agreement, the lease term commenced on November 1, 2021 with rental payments scheduled to commence on February 1, 2022. The lease term is for five years with no option for renewal. Annual lease payments are approximately $0.1 million. The Company recorded a right-of-use asset and a lease liability of approximately $0.4 million upon commencement of the lease and the lease is classified as an operating lease.

The Company’s leases have remaining lease terms of eight years to seventeen years. Some of our leases include one or more options to renew with renewal terms that can extend the lease for additional years, or options to terminate the leases, both at the Company’s discretion. The Company’s lease terms include options to extend or terminate leases when the Company concludes it is reasonably certain that it would exercise those options. Lease expense for minimum lease payments is recognized on a straight-line basis based on the fixed components of a lease arrangement. The Company amortizes this expense over the term of the lease beginning with the date of initial possession, which is the date the Company can enter the leased space and begin to make improvements in preparation for its intended use. Variable lease components represent amounts that are not fixed in nature and are not tied to an index or rate, and are recognized as incurred.

The table below presents the lease-related costs which are included in the consolidated statements of operations for the years ended as of March 31, 2022 and 2021:


	Twelve Months Ended March 31,
	2022		2021
Lease cost
Finance lease costs:
Amortization of right-to-use asset	$	2,428	$	2,428
Interest on lease liabilities	2,223		2,242
Operating lease costs	1,003		948
Total lease cost	$	5,654	$	5,618

The following table summarizes the classification of lease costs in the consolidated statement of operations for the years ended March 31, 2022 and 2021 as follows:


	Twelve Months Ended March 31,
	2022		2021
Finance Lease Costs
Research and development	$	2,070	$	2,070
Selling, general and administrative	358		358
Other income (expense)	2,223		2,242
Operating Lease Costs
Research and development	407		352
Selling, general and administrative	596		596
Total lease cost	$	5,654	$	5,618

The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the operating and financing lease liabilities recognized on our balance sheet as of March 31, 2022:


	March 31, 2022
	Operating leases		Financing lease		Total
2023	$	1,070	$	2,562	$	3,632
2024	1,079		2,639		3,718
2025	1,088		2,718		3,806
2026	1,098		2,799		3,897
2027	1,062		2,883		3,945
Thereafter	2,978		38,022		41,000
Total lease payments	8,375		51,623		59,998
Less: interest	2,504		24,655		27,159
Total lease liabilities	$	5,871	$	26,968	$	32,839

The following table provides lease disclosure as of and for the year ended March 31, 2022:


	March 31, 2022			March 31, 2021
Leases
Right-to-use operating lease asset	$	5,552		$	5,751
Right-to-use finance lease asset	42,094			44,522
Total lease assets	$	47,646		$	50,273
Operating lease liabilities, current	$	1,070		$	970
Finance lease liabilities, current	2,562			2,487
Operating lease liabilities, non-current	4,801			5,078
Finance lease liabilities, non-current	24,406			24,745
Total lease liabilities	$	32,839		$	33,280
Other information
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	968		$	823
Operating cash flows from finance leases	$	2,223		$	2,240
Financing cash flows from finance leases	$	264		$	145
Right-to-use asset obtained in exchange for new operating lease liabilities	$	363		$	1,580
Right-to-use asset obtained in exchange for new financing lease liabilities	$	—		$	—
Weighted-average remaining lease term – operating leases	7.7 years			8.9 years
Weighted-average remaining lease term – financing leases	17.3 years			18.3 years
Weighted-average discount rate – operating leases	10.1		%	9.8		%
Weighted-average discount rate – financing leases	8.3		%	8.3		%

The variable lease costs and short-term lease costs were insignificant for the years ended March 31, 2022 and 2021, respectively.

Manufacturing commitments

The Company has entered into an agreement with a contract manufacturing organization to provide clinical trial products. As of March 31, 2022 and 2021, the Company had committed to minimum payments under these arrangements totaling $1,951 and $1,651 through March 31, 2022.

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 March 31, 2022 or 2021.

Legal proceedings

The Company is not a party to any litigation and does not have contingency reserves established for any litigation liabilities.

Benefit plans	12 Months Ended
Benefit plans	Mar. 31, 2022
Retirement Benefits [Abstract]
Benefit plans	Benefit plans The Company established a defined-contribution savings plan under Section 401(k) of the Code (the “401(k) Plan”). The 401(k) Plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. Matching contributions to the 401(k) Plan may be made at the discretion of the Company’s board of directors. During the years ended March 31, 2022 and 2021, the Company made contributions totaling $1.1 million and $0.7 million, respectively, to the 401(k) Plan. We provide a pension contribution plan for our employees in the United Kingdom, pursuant to which we match our employees’ contributions each year in amounts up to 8% of their annual base salary.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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-Name Accounting Standards Codification
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+ Details

Income taxes

12 Months Ended

Mar. 31, 2022

Income Tax Disclosure [Abstract]

Income taxes

During the years ended March 31, 2022 and 2021, the Company recorded no income tax benefits for the net losses incurred due to the uncertainty of the realization of such losses. The Company’s net loss before income taxes were generated in the United States and the United Kingdom.

Net loss before income taxes for the years ended March 31, 2022 and 2021 were as follows:


	Year Ended March 31,
	2022	2021
United States	(28,985)	(22,775)
Foreign (United Kingdom)	(89,051)	(58,095)
Total	(118,036)	(80,870)

A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate for the years ended March 31, 2022 and 2021 is as follows:


	Year Ended March 31,
	2022		2021
U.S. Federal statutory income tax rate	-21.0	%	-21.0	%
State taxes, net of federal benefit	-0.3	%	-2.4	%
Research and development credits	0.0	%	-0.8	%
Research and development expenses	1.0	%	1.9	%
Return to provision	-0.2	%	0.0	%
Stock compensation	-2.1	%	-3.9	%
Foreign tax rate differential	1.5	%	0.0	%
Change in tax rates	-10.6	%	0.0	%
Change in valuation allowance	31.1	%	25.9	%
Other	0.6	%	0.3	%
	0.0	%	0.0	%

Components of the Company’s deferred tax assets as of March 31, 2022 and 2021 were as follows:


	Year Ended March 31,
	2022		2021
Deferred tax assets:
Federal net operating loss carryforwards	$	9,827	$	7,083
Foreign net operating loss carryforwards	48,588		22,195
State net operating loss carryforwards	2,697		2,358
Research & development credits	1,000		787
Property, plant and equipment	4,367		5,068
Capitalized start-up costs	1,286		1,597
Stock compensation	8,922		4,838
Accrued expense	1,452		739
Lease liability	7,309		8,462
Other	310		—
Total deferred tax assets	85,758		53,127
Valuation allowance	(74,892)		(40,028)
Net deferred tax assets	10,866		13,099

Deferred tax liabilities:
Right of Use Asset	(10,866)		(13,090)
Other	—		(9)
Total deferred tax liabilities	(10,866)		(13,099)
Net deferred tax assets (liabilities)	$	—	$	—

As of March 31, 2022, the Company had federal and foreign net operating loss carryforwards of approximately $46,797 and $194,354, respectively, which can be carried forward indefinitely. As of March 31, 2022, the Company had state net operating loss carryforwards of $42,710, which will begin to expire in 2039.

As of March 31, 2022, the Company had federal and state research and development carryforwards of approximately $709 and $367, respectively, which will begin to expire in 2041 and 2036, respectively.

Utilization of the U.S. federal and state net operating loss carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986, as amended, and corresponding provisions of state law, due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of net operating loss carryforwards that can be utilized annually to offset future taxable income and tax liabilities, respectively. The Company has not completed a study to assess whether a change of ownership has occurred, or whether there have been multiple ownership changes since its formation, due to the significant cost and complexity associated with such a study. Any limitation may result in expiration of a portion of the net operating loss carryforwards before utilization. Further, until a study is completed by the Company and any limitation is known, no amounts are being presented as an uncertain tax position.

Changes in the valuation allowance for deferred tax assets during the years ended March 31, 2022 and 2021 related primarily to the increase in net operating loss carryforwards were as follows:


	Year Ended March 31,
	2022		2021
Valuation allowance as of beginning of year	$	40,028	$	17,329
Increases recorded to income tax provision	36,679		22,624
(Decreases) increases recorded to income tax provision for equity	$	(1,815)	$	76
Valuation allowance as of end of year	$	74,892	$	40,028

As of March 31, 2022 and 2021, the Company had not recorded any amounts for unrecognized tax benefits. The Company’s policy is to record interest and penalties related to income taxes as part of its income tax provision. As of March 31, 2022 and 2021, the Company had no accrued interest or penalties related to uncertain tax positions and no amounts had been recognized in the Company’s consolidated statements of operations and comprehensive loss.

The Company files income tax returns in the United States, Massachusetts and the United Kingdom as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by U.S. federal, state and foreign jurisdictions, where applicable. There are currently no pending tax examinations. The Company is open to future tax examination in the U.S. under statute from 2019 to the present and in the United Kingdom from 2017 to the present. Although, with respect to the U.S. federal jurisdictions, carryforward attributes that were generated prior to 2019 may still be adjusted upon examination if they either have been or will be used in a future period.

As of March 31, 2022 and 2021, income taxes on undistributed earnings of the Company’s subsidiary have not been provided for as the Company planned to indefinitely reinvest these amounts, had the ability to do so, and the cumulative undistributed foreign earnings were in an overall deficit.

During the second quarter of 2021, the Finance Act 2021 (the Act) was enacted in the United Kingdom. The Act increases the corporate income tax rate from 19% to 25% effective April 1, 2023 and enhances the first-year capital allowance on qualifying new plant and machinery assets effective April 1, 2021. The effects on the Company’s existing deferred tax balances have been recorded and is offset by the valuation allowance maintained against the Company’s U.K. net deferred tax assets.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Geographic information

12 Months Ended

Mar. 31, 2022

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:


	March 31, 2022		March 31, 2021
United States	$	6,318	$	6,866
United Kingdom	1,615		576
	$	7,933	$	7,442

Subsequent Events	12 Months Ended
Subsequent Events	Mar. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsBetween April 1, 2022 and May 19, 2022, the Company settled transactions that occurred pursuant to the 2020 Sales Agreement, whereby the Company issued and sold an aggregate of 1,686,438 shares of its common stock between April 7, 2022 and April 19, 2022, resulting in gross proceeds of $32.0 million, before deducting fees of $1.0 million.

Summary of significant accounting policies (Policies)

12 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

Principles of consolidation

Use of estimates

Foreign currency and currency translation

Concentrations of credit risk and of significant suppliers

Cash and cash equivalents

Cash and cash equivalentsThe Company considers all highly liquid investments with original maturities of three months or less at date of purchase to be cash equivalents.

Restricted cash

Restricted cashThe Company holds restricted cash in segregated bank accounts in connection with a letter of credit.

Short-term investments

The Company’s short-term investments as of March 31, 2022 and 2021 had maturities of less than two years.

Property, plant and equipment


			Estimated Useful life
Office equipment			5 years
Computer equipment and software			3 years
Plant, manufacturing and laboratory equipment			5 years
Leasehold improvements			Lesser of lease term or 10 years

Impairment of long-lived assets

Fair value measurements

•Level 1 — Quoted prices in active markets for identical assets or liabilities.

Debt Issuance Costs

Debt issuance costs

Segment information

Research and development costs

Research contract costs and accruals

Patent costs

Stock-based compensation

Research and development incentives and receivable

Comprehensive loss

Comprehensive lossComprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders.

Income taxes

Net income (loss) per share

Recently adopted accounting pronouncements and Recently issued accounting pronouncements

Recently adopted accounting pronouncements

Recently issued accounting pronouncements

Summary of significant accounting policies (Tables)

12 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

Schedule of property, plant and equipment, net

Depreciation and amortization expense is recognized using the straight-line method over the estimated useful lives of the respective assets as follows:


			Estimated Useful life
Office equipment			5 years
Computer equipment and software			3 years
Plant, manufacturing and laboratory equipment			5 years
Leasehold improvements			Lesser of lease term or 10 years

Property, plant and equipment, net consisted of the following:


	March 31, 2022		March 31, 2021

Office equipment	$	937	$	830
Computer equipment	1,667		1,695
Plant and laboratory equipment	7,720		6,369
Leasehold improvements	785		784
Construction in progress	1,619		412
	12,728		10,090
Less: Accumulated depreciation and amortization	(4,795)		(2,648)
	$	7,933	$	7,442

Fair value of financial assets and liabilities (Tables)

12 Months Ended

Mar. 31, 2022

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 March 31, 2022 Using:
	Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	—	$	75,117	$	—	$	75,117
US Government Agency bonds	—		26,688		—		26,688
US Treasury bonds	—		263,019		—		263,019
	$	—	$	364,824	$	—	$	364,824


	Fair Value Measurements as of March 31, 2021 Using:
	Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	—	$	150,734	$	—	$	150,734
US Government Agency bonds	—		67,012		—		67,012
US Treasury bonds	—		226,772		—		226,772
	$	—	$	444,518	$	—	$	444,518

Short-term investments (Tables)

12 Months Ended

Mar. 31, 2022

Short-term Investments [Abstract]

Schedule of short-term investments

As of March 31, 2022 and 2021, the Company's available-for-sale investments by type, consisted of the following:


	March 31, 2022
	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
US Government agency bonds	$	26,827	$	—	$	(139)	$	26,688
US Treasury bonds	264,162		—		(1,143)		263,019
	$	290,989	$	—	$	(1,282)	$	289,707


	March 31, 2021
	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
US Government agency bonds	$	67,017	$	12	$	(17)	$	67,012
US Treasury bonds	226,722		55		(5)		226,772
	$	293,739	$	67	$	(22)	$	293,784

Property, plant and equipment, net (Tables)

12 Months Ended

Mar. 31, 2022

Property, Plant and Equipment [Abstract]

Schedule of property, plant and equipment, net

Depreciation and amortization expense is recognized using the straight-line method over the estimated useful lives of the respective assets as follows:


			Estimated Useful life
Office equipment			5 years
Computer equipment and software			3 years
Plant, manufacturing and laboratory equipment			5 years
Leasehold improvements			Lesser of lease term or 10 years

Property, plant and equipment, net consisted of the following:


	March 31, 2022		March 31, 2021

Office equipment	$	937	$	830
Computer equipment	1,667		1,695
Plant and laboratory equipment	7,720		6,369
Leasehold improvements	785		784
Construction in progress	1,619		412
	12,728		10,090
Less: Accumulated depreciation and amortization	(4,795)		(2,648)
	$	7,933	$	7,442

Accrued expenses and other current liabilities (Tables)

12 Months Ended

Mar. 31, 2022

Accrued expenses and other current liabilities

Schedule of accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following:


	March 31, 2022		March 31, 2021
Accrued research and development costs	$	5,882	$	3,862
Accrued compensation and benefits costs	5,569		3,952
Accrued professional fees	621		407
Other	1,320		514
	$	13,392	$	8,735

Stock-based compensation (Tables)

12 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Schedule of stock-based compensation expense

The following table summarizes the classification of stock-based compensation expense in the consolidated statements of operations for the years ended March 31, 2022 and 2021 as follows:


	Twelve Months Ended March 31,
	2022		2021
Research and development	$	8,568	$	5,749
Selling, general and administrative	15,686		6,041
	$	24,254	$	11,790

The following table summarizes stock-based compensation expense by award type for the years ended March 31, 2022 and 2021 as follows:


	Twelve Months Ended March 31,
	2022		2021
Stock options	$	19,160	$	11,778
Restricted stock units	5,094		12
	$	24,254	$	11,790

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:


	Twelve Months Ended March 31,
	2022		2021
Risk-free interest rate	1.18	%	0.93	%
Expected term (in years)	6.0		6.3
Expected volatility	79.8	%	75.4	%
Expected dividend yield	0	%	0	%

Summary of stock option activity

A summary of stock option activity under the Company’s equity incentive plans for the year ended March 31, 2022 is as follows:


	Number of Shares	Weighted Average Exercise Price		Weighted Average Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding as of March 31, 2021	6,460,184	$	13.26	7.95	$	116,193
Granted	1,573,862	31.29
Exercised	(768,186)	8.93
Cancelled	(751,526)	24.93
Outstanding as of March 31, 2022	6,514,334	16.78		7.26	$	30,358
Options exercisable as of March 31, 2021	2,698,708	$	8.38	6.79	$	59,717
Options exercisable as of March 31, 2022	3,645,749	$	10.85	6.31	$	24,875

Summary of changes in company's RSU

A summary of the changes in the Company’s RSUs during the year ended March 31, 2022 is as follows:


	Number of Restricted Shares	Weighted Average Grant Date Fair Value
Outstanding as of March 31, 2021	15,975	$	34.15
Granted	868,016	31.37
Vested	(3,993)	34.15
Cancelled	(53,785)	31.95
Outstanding as of March 31, 2022	826,213	$	31.38

Net loss per share (Tables)

12 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Schedule of calculation of basic and diluted net loss per share attributable to common stockholders

The following table sets forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders (in thousands, except per share amounts):


	Twelve Months Ended March 31,
	2022		2021
Numerator:
Net loss	$	(118,036)	$	(80,870)
Denominator:
Weighted average common shares outstanding, basic and diluted	52,212,269		46,248,969
Net loss per share, basic and diluted	$	(2.26)	$	(1.75)

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:


	Twelve Months Ended March 31,
	2022	2021
Options to purchase common stock	6,514,334	6,476,159
Warrants to purchase common stock	497,344	497,344
	7,011,678	6,973,503

Commitments and contingencies (Tables)

12 Months Ended

Mar. 31, 2022

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 years ended as of March 31, 2022 and 2021:


	Twelve Months Ended March 31,
	2022		2021
Lease cost
Finance lease costs:
Amortization of right-to-use asset	$	2,428	$	2,428
Interest on lease liabilities	2,223		2,242
Operating lease costs	1,003		948
Total lease cost	$	5,654	$	5,618

The following table summarizes the classification of lease costs in the consolidated statement of operations for the years ended March 31, 2022 and 2021 as follows:


	Twelve Months Ended March 31,
	2022		2021
Finance Lease Costs
Research and development	$	2,070	$	2,070
Selling, general and administrative	358		358
Other income (expense)	2,223		2,242
Operating Lease Costs
Research and development	407		352
Selling, general and administrative	596		596
Total lease cost	$	5,654	$	5,618

Summary of the maturity of company's lease liabilities


	March 31, 2022
	Operating leases		Financing lease		Total
2023	$	1,070	$	2,562	$	3,632
2024	1,079		2,639		3,718
2025	1,088		2,718		3,806
2026	1,098		2,799		3,897
2027	1,062		2,883		3,945
Thereafter	2,978		38,022		41,000
Total lease payments	8,375		51,623		59,998
Less: interest	2,504		24,655		27,159
Total lease liabilities	$	5,871	$	26,968	$	32,839

Schedule of additional information related to leases

The following table provides lease disclosure as of and for the year ended March 31, 2022:


	March 31, 2022			March 31, 2021
Leases
Right-to-use operating lease asset	$	5,552		$	5,751
Right-to-use finance lease asset	42,094			44,522
Total lease assets	$	47,646		$	50,273
Operating lease liabilities, current	$	1,070		$	970
Finance lease liabilities, current	2,562			2,487
Operating lease liabilities, non-current	4,801			5,078
Finance lease liabilities, non-current	24,406			24,745
Total lease liabilities	$	32,839		$	33,280
Other information
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	968		$	823
Operating cash flows from finance leases	$	2,223		$	2,240
Financing cash flows from finance leases	$	264		$	145
Right-to-use asset obtained in exchange for new operating lease liabilities	$	363		$	1,580
Right-to-use asset obtained in exchange for new financing lease liabilities	$	—		$	—
Weighted-average remaining lease term – operating leases	7.7 years			8.9 years
Weighted-average remaining lease term – financing leases	17.3 years			18.3 years
Weighted-average discount rate – operating leases	10.1		%	9.8		%
Weighted-average discount rate – financing leases	8.3		%	8.3		%

Income taxes (Tables)

12 Months Ended

Mar. 31, 2022

Income Tax Disclosure [Abstract]

Schedule of net loss before income taxes

Net loss before income taxes for the years ended March 31, 2022 and 2021 were as follows:


	Year Ended March 31,
	2022	2021
United States	(28,985)	(22,775)
Foreign (United Kingdom)	(89,051)	(58,095)
Total	(118,036)	(80,870)

Schedule of reconciliation of the U.S federal statutory income tax rate

A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate for the years ended March 31, 2022 and 2021 is as follows:


	Year Ended March 31,
	2022		2021
U.S. Federal statutory income tax rate	-21.0	%	-21.0	%
State taxes, net of federal benefit	-0.3	%	-2.4	%
Research and development credits	0.0	%	-0.8	%
Research and development expenses	1.0	%	1.9	%
Return to provision	-0.2	%	0.0	%
Stock compensation	-2.1	%	-3.9	%
Foreign tax rate differential	1.5	%	0.0	%
Change in tax rates	-10.6	%	0.0	%
Change in valuation allowance	31.1	%	25.9	%
Other	0.6	%	0.3	%
	0.0	%	0.0	%

Schedule of components of deferred tax assets and liabilities

Components of the Company’s deferred tax assets as of March 31, 2022 and 2021 were as follows:


	Year Ended March 31,
	2022		2021
Deferred tax assets:
Federal net operating loss carryforwards	$	9,827	$	7,083
Foreign net operating loss carryforwards	48,588		22,195
State net operating loss carryforwards	2,697		2,358
Research & development credits	1,000		787
Property, plant and equipment	4,367		5,068
Capitalized start-up costs	1,286		1,597
Stock compensation	8,922		4,838
Accrued expense	1,452		739
Lease liability	7,309		8,462
Other	310		—
Total deferred tax assets	85,758		53,127
Valuation allowance	(74,892)		(40,028)
Net deferred tax assets	10,866		13,099

Deferred tax liabilities:
Right of Use Asset	(10,866)		(13,090)
Other	—		(9)
Total deferred tax liabilities	(10,866)		(13,099)
Net deferred tax assets (liabilities)	$	—	$	—

Schedule of changes in the valuation allowance for deferred tax assets

Changes in the valuation allowance for deferred tax assets during the years ended March 31, 2022 and 2021 related primarily to the increase in net operating loss carryforwards were as follows:


	Year Ended March 31,
	2022		2021
Valuation allowance as of beginning of year	$	40,028	$	17,329
Increases recorded to income tax provision	36,679		22,624
(Decreases) increases recorded to income tax provision for equity	$	(1,815)	$	76
Valuation allowance as of end of year	$	74,892	$	40,028

Geographic information (Tables)

12 Months Ended

Mar. 31, 2022

Segments, Geographical Areas [Abstract]

Summary of company's long-lived assets held in different geographic regions

Information about the Company’s long-lived assets held in different geographic regions is presented in the tables below:


	March 31, 2022		March 31, 2021
United States	$	6,318	$	6,866
United Kingdom	1,615		576
	$	7,933	$	7,442

Nature of the business (Details) - USD ($) $ in Thousands	12 Months Ended
Nature of the business (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ (118,036)	$ (80,870)
Accumulated deficit	$ (311,204)	$ (193,168)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

- Definition

The cumulative amount of the reporting entity's undistributed earnings or deficit.

+ References + Details

Summary of significant accounting policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accounting Policies [Abstract]
Cash equivalents	$ 75,117	$ 150,734
Summary of significant accounting policies
Restricted cash	1,636	1,636
Research and development incentives income	3,170	2,807
Research and development incentives receivable, current	3,055	2,953
Foreign currency transaction loss	748	866
Unrealized gain (loss) on short-term investments, net of tax	$ 1,327	278
Minimum percentage of benefit recognized is being realized upon ultimate settlement	50.00%
United Kingdom \| Maximum
Summary of significant accounting policies
Percentage of qualifying research and development expenses reimbursed by government	14.50%
Operating Lease
Summary of significant accounting policies
Restricted cash	$ 1,636	$ 1,636
Office equipment
Summary of significant accounting policies
Property, plant and equipment, useful life (in years)	5 years
Computer equipment and software
Summary of significant accounting policies
Property, plant and equipment, useful life (in years)	3 years
Plant, manufacturing and laboratory equipment
Summary of significant accounting policies
Property, plant and equipment, useful life (in years)	5 years
Leasehold improvements
Summary of significant accounting policies
Property, plant and equipment, useful life (in years)	10 years

Fair value of financial assets and liabilities (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Fair value of financial assets and liabilities
Assets fair value	$ 364,824	$ 444,518
Money market funds
Fair value of financial assets and liabilities
Assets fair value	75,117	150,734
US Government Agency bonds
Fair value of financial assets and liabilities
Assets fair value	26,688	67,012
US Treasury bonds
Fair value of financial assets and liabilities
Assets fair value	263,019	226,772
Level 1
Fair value of financial assets and liabilities
Assets fair value	0	0
Level 1 \| Money market funds
Fair value of financial assets and liabilities
Assets fair value	0	0
Level 1 \| US Government Agency bonds
Fair value of financial assets and liabilities
Assets fair value	0	0
Level 1 \| US Treasury bonds
Fair value of financial assets and liabilities
Assets fair value	0	0
Level 2
Fair value of financial assets and liabilities
Assets fair value	364,824	444,518
Level 2 \| Money market funds
Fair value of financial assets and liabilities
Assets fair value	75,117	150,734
Level 2 \| US Government Agency bonds
Fair value of financial assets and liabilities
Assets fair value	26,688	67,012
Level 2 \| US Treasury bonds
Fair value of financial assets and liabilities
Assets fair value	263,019	226,772
Level 3
Fair value of financial assets and liabilities
Assets fair value	0	0
Level 3 \| Money market funds
Fair value of financial assets and liabilities
Assets fair value	0	0
Level 3 \| US Government Agency bonds
Fair value of financial assets and liabilities
Assets fair value	0	0
Level 3 \| US Treasury bonds
Fair value of financial assets and liabilities
Assets fair value	$ 0	$ 0

Short-term investments (Details) - Short-term investments - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Short-term investments
Amortized cost	$ 290,989	$ 293,739
Gross unrealized gains	0	67
Gross unrealized losses	(1,282)	(22)
Fair value	289,707	293,784
US Government Agency bonds
Short-term investments
Amortized cost	26,827	67,017
Gross unrealized gains	0	12
Gross unrealized losses	(139)	(17)
Fair value	26,688	67,012
US Treasury bonds
Short-term investments
Amortized cost	264,162	226,722
Gross unrealized gains	0	55
Gross unrealized losses	(1,143)	(5)
Fair value	263,019	$ 226,772
2023	7,600
2024	$ 54,200

Property, plant and equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Property, plant and equipment, net
Property, plant and equipment , gross	$ 12,728	$ 10,090
Less: Accumulated depreciation and amortization	(4,795)	(2,648)
Property, plant and equipment , net	7,933	7,442
Depreciation and amortization expense	2,147	1,711
Office equipment
Property, plant and equipment, net
Property, plant and equipment , gross	937	830
Computer equipment
Property, plant and equipment, net
Property, plant and equipment , gross	1,667	1,695
Plant and laboratory equipment
Property, plant and equipment, net
Property, plant and equipment , gross	7,720	6,369
Leasehold improvements
Property, plant and equipment, net
Property, plant and equipment , gross	785	784
Construction in progress
Property, plant and equipment, net
Property, plant and equipment , gross	$ 1,619	$ 412

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Accrued expenses and other current liabilities
Accrued research and development costs	$ 5,882	$ 3,862
Accrued compensation and benefits costs	5,569	3,952
Accrued professional fees	621	407
Other	1,320	514
Total	$ 13,392	$ 8,735

Long-term debt - Hercules Loan Agreement (Details) - USD ($)				12 Months Ended
	Dec. 15, 2020	Jun. 01, 2020	Aug. 08, 2019	Mar. 31, 2022	Mar. 31, 2021	May 31, 2020
Debt Securities [Abstract]
Loss on extinguishment of debt				$ 0	$ 913,000
Total paid amount				0	10,000,000
Interest expense				0	818,000
Noncash interest expense				0	$ 181,000
Hercules Loan Agreement
Debt Securities [Abstract]
Maximum borrowing capacity		$ 40,000,000	$ 30,000,000			$ 30,000,000
Borrowed amount			10,000,000
Payment of issuance costs			225,000
Additional closing and legal fees		100,000	130,000
Maximum draw per each of three tranches		10,000,000
Loss on extinguishment of debt	$ 913,000
Total paid amount	10,839,000
Outstanding principal	10,000,000
Term charge	495,000
Termination fee due	300,000
Accrued interest	$ 44,000
Upfront fees, including closing costs and legal fees		$ 100,000	$ 355,000
Interest expense				818,000
Noncash interest expense				181,000
Accretion of the debt discount				82,000
Accretion of the final payment				$ 99,000

Stockholders' equity - Common Stock and Undesignated Preferred Stock (Details) - $ / shares	Mar. 31, 2022	Mar. 31, 2021
Stockholders' Equity
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
Stock options
Stockholders' Equity
Common stock reserved for issuance (in shares)	16,605,804	14,572,115

Stockholders' equity - ATM Program (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended
	Aug. 11, 2020	Jun. 30, 2020	Aug. 31, 2019	Mar. 31, 2022	Mar. 31, 2021
Class of Warrant or Right [Line Items]
Common stock, par value (in dollars per share)				$ 0.001	$ 0.001
ATM sales
Class of Warrant or Right [Line Items]
Commission percentage			3.00%
ATM sales \| Common stock
Class of Warrant or Right [Line Items]
Common stock, par value (in dollars per share)	$ 0.001		$ 0.001
Securities offered to the public during the period	$ 350,000
ATM sales \| Common stock \| Maximum
Class of Warrant or Right [Line Items]
Aggregate offering amount	$ 62,500	$ 30,000	$ 75,000

Stockholders' equity - Equity offerings (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				12 Months Ended
	Oct. 31, 2020	Jun. 30, 2020	Dec. 31, 2019	Nov. 30, 2019	Mar. 31, 2022	Mar. 31, 2021
Class of Warrant or Right [Line Items]
Proceeds from issuance of common stock in follow-on public offering, net of underwriting fees and discounts	$ 269,975	$ 107,782		$ 85,598	$ 0	$ 286,107
Underwriting discounts, commissions and other offering expenses					$ 0	$ 100
Number of common stocks are exercisable from the november 2019 pre-funded warrants and the june 2020 pre-funded warrants (in shares)					5,284,238
Underwriter rights
Class of Warrant or Right [Line Items]
Number of shares issued (in shares)	5,625,000	3,478,261	838,530	4,516,561
Issuance of pre-funded warrants (in shares)				2,200,000
Public offering price (in dollars per share)	$ 40.00	$ 23.00		$ 13.61
Underwriting discounts, commissions and other offering expenses	$ 17,525
Shares issued during period (in shares)	937,500	652,173
Pre-Funded Warrants
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	1,562,500	1,521,738
Sale of stock, purchase period	30 days	30 days		30 days
Public offering price (in dollars per share)	$ 39.9999	$ 22.9999		$ 13.6099
Variation between public offering prices of common stock and pre-funded warrants (in dollars per share)	$ 0.0001	$ 0.0001		$ 0.0001
Maximum percentage of holding for exercise warrants	9.99%	9.99%		9.99%
Maximum percentage of increase (decrease) of holding for exercise warrants	19.99%	19.99%
Prior notice period to change percentage of holding	61 days	61 days
November 2019 Underwriting Agreement
Class of Warrant or Right [Line Items]
Underwriting discounts, commissions and other offering expenses				$ 5,814
June 2020 Underwriting Agreement
Class of Warrant or Right [Line Items]
Underwriting discounts, commissions and other offering expenses		$ 7,217

Stock-based compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions				1 Months Ended	12 Months Ended
	Apr. 01, 2020	Apr. 01, 2019	Jul. 09, 2018	May 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Stock-Based Compensation
Unrecognized compensation cost related to unvested common stock options					$ 37.9
Expenses expected to be recognized over a weighted average remaining period					2 years 6 months 3 days
Weighted average grant-date fair value (in dollars per share)					$ 21.40	$ 12.03
Intrinsic value of stock options exercised					$ 16.2	$ 24.9
Granted (in shares)				125,000	1,573,862
2017 Plan
Stock-Based Compensation
Shares authorized (in shares)					2,659,885
Number of shares available for grant (in shares)			2,520,247
2018 Plan
Stock-Based Compensation
Shares authorized (in shares)			3,617,968
Number of shares available for grant (in shares)					1,933,300
Share based payment award percentage of outstanding shares			4.00%
Additional shares authorized (in shares)	2,074,028	1,466,749
ESPP
Stock-Based Compensation
Share based payment award percentage of outstanding shares			1.00%
Additional shares authorized (in shares)	518,507	366,687	697,224
Common stock reserved for issuance (in shares)	1,550,375		348,612
Stock options
Stock-Based Compensation
Exercise price for persons holding ten percent of voting power (as a percent)					100.00%
Exercise price for persons holding more than ten percent of voting power (as a percent)					110.00%
Share based payment award expiration period					10 years
Share based payment award vesting period					4 years
Common stock reserved for issuance (in shares)					16,605,804	14,572,115
Stock options \| Minimum
Stock-Based Compensation
Expiration period for persons holding more than ten percent of voting power					10 years
Stock options \| Maximum
Stock-Based Compensation
Expiration period for persons holding ten percent of voting power					5 years
Restricted stock units
Stock-Based Compensation
Share based payment award vesting period					4 years
Expenses expected to be recognized over a weighted average remaining period					3 years 3 months 18 days
Granted (in shares)					868,016
Granted (in dollars per share)					$ 31.37
Unrecognized compensation cost					$ 21.0
Restricted stock units \| Share-based Payment Arrangement, Tranche One
Stock-Based Compensation
Share based payment award vesting period					1 year
Restricted stock units \| Newly-Hired Executive
Stock-Based Compensation
Granted (in shares)				88,333

Stock-based compensation - Classification of expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Stock-Based Compensation
Stock-based compensation expense	$ 24,254	$ 11,790
Stock options
Stock-Based Compensation
Stock-based compensation expense	19,160	11,778
Restricted stock units
Stock-Based Compensation
Stock-based compensation expense	5,094	12
Research and development
Stock-Based Compensation
Stock-based compensation expense	8,568	5,749
Selling, general and administrative
Stock-Based Compensation
Stock-based compensation expense	$ 15,686	$ 6,041

Stock-based compensation - Assumptions to determine grant-date fair value of stock options (Details) - Stock options	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Stock-based Compensation
Risk-free interest rate	1.18%	0.93%
Expected term (in years)	6 years	6 years 3 months 18 days
Expected volatility	79.80%	75.40%
Expected dividend yield	0.00%	0.00%

Stock-based compensation - Stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Number of Shares
Outstanding at beginning of the period (in shares)		6,460,184
Granted (in shares)	125,000	1,573,862
Exercised (in shares)		(768,186)
Cancelled (in shares)		(751,526)
Outstanding at end of the period (in shares)		6,514,334	6,460,184
Options exercisable (in shares)		3,645,749	2,698,708
Weighted Average Exercise Price
Outstanding at beginning of the period (in dollars per share)		$ 13.26
Granted (in dollars per share)		31.29
Exercised (in dollars per share)		8.93
Cancelled (in dollars per share)		24.93
Outstanding at end of the period (in dollars per share)		16.78	$ 13.26
Options exercisable (in dollars per share)		$ 10.85	$ 8.38
Weighted Average Contractual Term (Years)
Outstanding (years)		7 years 3 months 3 days	7 years 11 months 12 days
Options exercisable (years)		6 years 3 months 21 days	6 years 9 months 14 days
Aggregate Intrinsic Value
Outstanding		$ 30,358	$ 116,193
Options exercisable		$ 24,875	$ 59,717

Stock-based compensation - Summary of RSU Activity (Details) - Restricted stock units	12 Months Ended
	Mar. 31, 2022 $ / shares shares
Number of Restricted Shares
Beginning balance (in shares) \| shares	15,975
Granted (in shares) \| shares	868,016
Vested (in shares) \| shares	(3,993)
Cancelled (in shares) \| shares	(53,785)
Ending balance (in shares) \| shares	826,213
Weighted Average Grant Date Fair Value
Beginning balance (in dollars per share) \| $ / shares	$ 34.15
Granted (in dollars per share) \| $ / shares	31.37
Vested (in dollars per share) \| $ / shares	34.15
Cancelled (in dollars per share) \| $ / shares	31.95
Ending balance (in dollars per share) \| $ / shares	$ 31.38

Net loss per share - Computation of Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss	$ (118,036)	$ (80,870)
Denominator:
Weighted average common shares outstanding, basic (in shares)	52,212,269	46,248,969
Weighted average common shares outstanding, diluted (in shares)	52,212,269	46,248,969
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (2.26)	$ (1.75)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (2.26)	$ (1.75)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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+ Details

Net loss per share - Computation of diluted net loss per share attributable to common stockholders (Details) - shares	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Diluted net loss per share attributable to common stockholders
Antidilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	7,011,678	6,973,503
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)	6,514,334	6,476,159
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

Significant agreements (Details) $ in Thousands	1 Months Ended	12 Months Ended
Significant agreements (Details) $ in Thousands	Jan. 31, 2020 patient	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)
Significant agreements
Prepaid expenses and other current assets		$ 5,267	$ 4,492
Bristol-Myers Squibb Company
Significant agreements
Number of patients \| patient	125
Regeneron Pharmaceuticals, Inc
Significant agreements
Proceeds from collaborators		6,100	5,100
Prepaid expenses and other current assets		$ 2,000	$ 1,300

Commitments and contingencies - Narrative (Details) $ in Thousands	Mar. 31, 2022 USD ($)	Oct. 31, 2021 USD ($) ft²	Mar. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Rentable square feet (in square feet) \| ft²		2,951
Lease term (in years)		5 years
Annual lease payments		$ 100
Right-to-use liability	$ 5,871	400
Right-to-use asset – operating leases	5,552	$ 400	$ 5,751
Minimum payments committed to manufacturing organization	$ 1,951		$ 1,651
Minimum
Lessee, Lease, Description [Line Items]
Lease term (in years)	8 years
Lease term (in years)	8 years
Maximum
Lessee, Lease, Description [Line Items]
Lease term (in years)	17 years
Lease term (in years)	17 years

Commitments and contingencies - Components of lease expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Finance lease costs:
Amortization of right-to-use asset	$ 2,428	$ 2,428
Interest on lease liabilities	2,223	2,242
Operating lease costs	1,003	948
Total lease cost	$ 5,654	$ 5,618

Commitments and contingencies - Income Statement Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lessee, Lease, Description [Line Items]
Finance Lease Costs	$ 2,428	$ 2,428
Interest on lease liabilities	2,223	2,242
Operating Lease Costs	1,003	948
Total lease cost	5,654	5,618
Research and development
Lessee, Lease, Description [Line Items]
Finance Lease Costs	2,070	2,070
Operating Lease Costs	407	352
Total lease cost	5,654	5,618
Selling, general and administrative
Lessee, Lease, Description [Line Items]
Finance Lease Costs	358	358
Operating Lease Costs	$ 596	$ 596

Commitments and contingencies - Future lease payments under operating and financing lease liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Oct. 31, 2021
Operating leases
2023	$ 1,070
2024	1,079
2025	1,088
2026	1,098
2027	1,062
Thereafter	2,978
Total lease payments	8,375
Less: interest	2,504
Total lease liabilities	5,871	$ 400
Financing lease
2023	2,562
2024	2,639
2025	2,718
2026	2,799
2027	2,883
Thereafter	38,022
Total lease payments	51,623
Less: interest	24,655
Total lease liabilities	26,968
Total
2023	3,632
2024	3,718
2025	3,806
2026	3,897
2027	3,945
Thereafter	41,000
Total lease payments	59,998
Less: interest	27,159
Total lease liabilities	$ 32,839

Commitments and contingencies - Additional information related to leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Oct. 31, 2021
Leases
Right-to-use operating lease asset	$ 5,552	$ 5,751	$ 400
Right-to-use finance lease asset	42,094	44,522
Total lease assets	47,646	50,273
Operating lease liabilities, current	1,070	970
Finance lease liabilities, current	2,562	2,487
Operating lease liabilities, non-current	4,801	5,078
Financing lease liabilities, non-current	24,406	24,745
Total lease liabilities	32,839	33,280
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	968	823
Operating cash flows from finance leases	2,223	2,240
Principal payment of finance lease obligation	(264)	(145)
Right-to-use asset obtained in exchange for new operating lease liabilities	$ 363	$ 1,580
Weighted-average remaining lease term – operating leases	7 years 8 months 12 days	8 years 10 months 24 days
Right-to-use asset obtained in exchange for new financing lease liabilities	$ 0	$ 0
Weighted-average remaining lease term – financing leases	17 years 3 months 18 days	18 years 3 months 18 days
Weighted-average discount rate – operating leases	10.10%	9.80%
Weighted-average discount rate – financing leases	8.30%	8.30%

Benefit plans (Details) - USD ($) $ in Thousands	12 Months Ended
Benefit plans (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
401(k) Plan
Defined Contribution Plan Disclosure [Line Items]
Contributions to the plan	$ 1,100	$ 700
Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Maximum percentage of contribution by employee of their annual base salary (as a percent)	8.00%

Income taxes - Narrative (Details) - USD ($)	12 Months Ended
Income taxes - Narrative (Details) - USD ($)	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income tax benefit	$ 0	$ 0
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits	0	0
Accrued interest or penalties related to uncertain tax positions	0	$ 0
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	46,797,000
Tax credit carryforward, amount	709,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	194,354,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	42,710,000
Tax credit carryforward, amount	$ 367,000

Income taxes - Net loss before income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest [Abstract]
United States	$ (28,985)	$ (22,775)
Foreign (United Kingdom)	(89,051)	(58,095)
Total	$ (118,036)	$ (80,870)

- Definition

Amount after tax of income (loss) from continuing operations attributable to the parent.

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Income taxes - Reconciliation of the U.S federal statutory income tax rate (Details)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Reconciliation of the U.S federal statutory income tax rate
U.S. Federal statutory income tax rate	(21.00%)	(21.00%)
State taxes, net of federal benefit	(0.30%)	(2.40%)
Research and development credits	0.00%	(0.80%)
Research and development expenses	1.00%	1.90%
Return to provision	(0.20%)	0.00%
Stock compensation	(2.10%)	(3.90%)
Foreign tax rate differential	1.50%	0.00%
Change in tax rates	(10.60%)	0.00%
Change in valuation allowance	31.10%	25.90%
Other	0.60%	0.30%
Effective income tax rate	(0.00%)	(0.00%)

Income taxes - Components of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Deferred tax assets:
Federal net operating loss carryforwards	$ 9,827	$ 7,083
Foreign net operating loss carryforwards	48,588	22,195
State net operating loss carryforwards	2,697	2,358
Research & development credits	1,000	787
Property, plant and equipment	4,367	5,068
Capitalized start-up costs	1,286	1,597
Stock compensation	8,922	4,838
Accrued expense	1,452	739
Lease liability	7,309	8,462
Other	310	0
Total deferred tax assets	85,758	53,127
Valuation allowance	(74,892)	(40,028)	$ (17,329)
Net deferred tax assets	10,866	13,099
Deferred tax liabilities:
Right of Use Asset	(10,866)	(13,090)
Other	0	(9)
Total deferred tax liabilities	(10,866)	(13,099)
Net deferred tax assets (liabilities)	$ 0	$ 0

Income taxes - Valuation allowance for deferred tax assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Deferred Tax Assets, Valuation Allowance [Roll Forward]
Valuation allowance as of beginning of year	$ 40,028	$ 17,329
Increases recorded to income tax provision	36,679	22,624
(Decreases) increases recorded to income tax provision for equity	(1,815)	76
Valuation allowance as of end of year	$ 74,892	$ 40,028

Geographic information (Details) $ in Thousands	12 Months Ended
Geographic information (Details) $ in Thousands	Mar. 31, 2022 USD ($) region	Mar. 31, 2021 USD ($)
Segments, Geographical Areas [Abstract]
Number of operating geographic regions \| region	2
Geographic information
Long-lived assets	$ 7,933	$ 7,442
United States
Geographic information
Long-lived assets	6,318	6,866
United Kingdom
Geographic information
Long-lived assets	$ 1,615	$ 576

Subsequent Events (Details) - USD ($) $ in Thousands	1 Months Ended				12 Months Ended
Subsequent Events (Details) - USD ($) $ in Thousands	May 19, 2022	Oct. 31, 2020	Jun. 30, 2020	Nov. 30, 2019	Mar. 31, 2022	Mar. 31, 2021
Subsequent Event [Line Items]
Gross proceeds		$ 269,975	$ 107,782	$ 85,598	$ 0	$ 286,107
Subsequent Event
Subsequent Event [Line Items]
Shares issued during period (in shares)	1,686,438
Gross proceeds	$ 32,000
Issuance costs and underwriter fees	$ (1,000)