0001104659-21-069611 | 10-K | XBRL Viewer

Year Ended March 31,

United States

Foreign (United Kingdom)

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Mar. 31, 2021	May 17, 2021
Cover [Abstract]
Entity Registrant Name	Replimune Group, Inc.
Entity Central Index Key	0001737953
Document Type	10-K
Document Period End Date	Mar. 31, 2021
Amendment Flag	false
Current Fiscal Year End Date	--03-31
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 Public Float	$ 500.2
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		46,608,958
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	REPL
Security Exchange Name	NASDAQ

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Current assets:
Cash and cash equivalents	$ 182,518	$ 59,500
Short-term investments	293,784	109,055
Research and development incentives receivable	2,953	2,962
Prepaid expenses and other current assets	4,492	2,734
Total current assets	483,747	174,251
Property, plant and equipment, net	7,442	6,860
Restricted cash	1,636	1,636
Right-to-use asset-operating leases	5,751	4,425
Right-to-use asset-financing leases	44,522	46,925
Total assets	543,098	234,097
Current liabilities:
Accounts payable	2,355	3,434
Accrued expenses and other current liabilities	8,735	5,156
Operating lease liabilities, current	970	873
Financing lease liabilities, current	2,487	2,411
Total current liabilities	14,547	11,874
Long term debt, net of debt discount		9,801
Operating lease liabilities, non-current	5,078	3,737
Financing lease liabilities, non-current	24,745	24,967
Total liabilities	44,370	50,379
Commitments and contingencies (Note 12)
Stockholders' Equity
Common stock, $0.001 par value; 150,000,000 shares authorized as of March 31, 2021 and March 31, 2020; 46,566,481 and 36,668,743 shares issued and outstanding as of March 31, 2021 and March 31, 2020, respectively	47	37
Additional paid-in capital	692,243	296,961
Accumulated deficit	(193,168)	(112,298)
Accumulated other comprehensive loss	(394)	(982)
Total stockholders' equity	498,728	183,718
Total liabilities and stockholders' equity	$ 543,098	$ 234,097

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2021	Mar. 31, 2020
CONDENSED CONSOLIDATED BALANCE SHEETS
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized	150,000,000	150,000,000
Common stock, issued	46,566,481	36,668,743
Common stock, outstanding	46,566,481	36,668,743

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating expenses:
Research and development	$ 56,754	$ 38,761
General and administrative	23,201	17,437
Total operating expenses	79,955	56,198
Loss from operations	(79,955)	(56,198)
Other income (expense):
Research and development incentives	2,807	3,084
Investment income	916	2,424
Interest expense on finance lease liability	(2,242)	(1,185)
Interest expense on debt obligations	(818)	(734)
Loss on extinguishment of debt	(913)
Other (expense) income	(665)	(16)
Total other (expense) income, net	(915)	3,573
Net loss attributable to common stockholders	$ (80,870)	$ (52,625)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (1.75)	$ (1.54)
Weighted average common shares outstanding, basic and diluted (in shares)	46,248,969	34,261,548

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (80,870)	$ (52,625)
Other comprehensive loss:
Foreign currency translation gain (loss)	866	(236)
Net unrealized (loss) gain on short-term investments, net of tax of $0	(278)	309
Comprehensive loss	$ (80,282)	$ (52,552)

- 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

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other comprehensive loss:
Net unrealized (loss) gain on short-term investments, tax	$ 0	$ 0

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Common stock ATM sales	Common stock Follow-on public offering	Common stock	Additional paid-in capital ATM sales	Additional paid-in capital Follow-on public offering	Additional paid-in capital	Accumulated deficit Impact of adoption of ASC 842	Accumulated deficit	Accumulated other comprehensive loss	Impact of adoption of ASC 842	ATM sales	Follow-on public offering	Total
Balance at Mar. 31, 2019			$ 32			$ 198,645		$ (59,766)	$ (1,055)				$ 137,856
Balance (in shares) at Mar. 31, 2019			31,656,950
Increase (decrease) in Stockholders' Equity
Issuance of prefunded warrants to purchase common stock, net of issuance costs						28,145							28,145
Issuance of common stock, net of issuance costs and underwriter fees		$ 5		$ 4,431	$ 57,448						$ 4,431	$ 57,453
Issuance of common stock, net of issuance costs and underwriter fees (in shares)	287,559	4,516,561									287,559
Foreign currency translation adjustment									(236)				(236)
Unrealized loss on short-term investments, net of tax									309				309
Exercise of stock options						551							551
Exercise of stock options (in shares)			207,673
Stock-based compensation expense						7,741							7,741
Net loss								(52,625)					(52,625)
Balance at Mar. 31, 2020			$ 37			296,961	$ 93	(112,298)	(982)	$ 93			183,718
Balance (in shares) at Mar. 31, 2020			36,668,743
Increase (decrease) in Stockholders' Equity
Issuance of prefunded warrants to purchase common stock, net of issuance costs						91,650							91,650
Issuance of common stock, net of issuance costs and underwriter fees			$ 8			286,099							286,107
Issuance of common stock, net of issuance costs and underwriter fees (in shares)			9,103,261
Foreign currency translation adjustment									866				866
Unrealized loss on short-term investments, net of tax									(278)				(278)
Exercise of stock options			$ 2			5,743							$ 5,745
Exercise of stock options (in shares)			794,477										794,477
Stock-based compensation expense						11,790							$ 11,790
Net loss								(80,870)					(80,870)
Balance at Mar. 31, 2021			$ 47			$ 692,243		$ (193,168)	$ (394)				$ 498,728
Balance (in shares) at Mar. 31, 2021			46,566,481

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Prefunded warrants
Issuance costs and underwriter fees	$ 5,850	$ 1,797
Common stock
Issuance costs and underwriter fees	$ 18,892
Common stock \| ATM sales
Issuance costs and underwriter fees		137
Common stock \| Follow-on public offering
Issuance costs and underwriter fees		$ 4,017

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (80,870)	$ (52,625)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	11,790	7,741
Depreciation and amortization	1,711	533
Net amortization of premiums and discounts on short-term investments	1,376	(945)
Noncash interest expense	181	156
Loss on extinguishment of debt	913
Changes in operating assets and liabilities:
Research and development incentives receivable	325	(628)
Prepaid expenses and other current assets	(1,707)	933
Operating lease, right-of-use-asset	447	588
Finance lease, right-of-use-asset	2,403	1,274
Long term prepaid rent		(15,787)
Accounts payable	(1,031)	(3,821)
Accrued expenses and other current liabilities	3,413	2,479
Operating lease liabilities	(340)	(450)
Net cash used in operating activities	(61,389)	(60,552)
Cash flows from investing activities:
Purchases of property, plant and equipment	(2,392)	(6,540)
Purchase of short-term investments	(392,434)	(149,682)
Proceed from sales and maturities of short-term investments	206,050	150,989
Net cash (used in) investing activities	(188,776)	(5,233)
Cash flows from financing activities:
Proceeds from issuance of common stock in follow-on public offering, net of underwriting fees and discounts	286,107	57,453
Proceeds from issuance of prefunded warrants to purchase common stock, net of underwriting fees and discounts	91,650	28,145
Proceeds from issuance of common stock through ATM sales		4,431
Proceeds from long-term debt		10,000
Exercise of stock options	5,745	551
Payment of debt issuance costs	(100)	(355)
Principal payment of finance lease obligation	(145)	(59)
Principal payment of long-term debt	(10,000)
Payment of long-term debt extinguishment costs	(795)
Net cash provided by financing activities	372,462	100,166
Effect of exchange rate changes on cash, cash equivalents and restricted cash	721	(135)
Net increase (decrease) in cash, cash equivalents and restricted cash	123,018	34,246
Cash, cash equivalents and restricted cash at beginning of period	61,136	26,890
Cash, cash equivalents and restricted cash at end of period	184,154	61,136
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	636	578
Supplemental disclosure of non-cash investing and financing activities:
Net unrealized (loss) gain on short-term investments	(278)	309
Purchases of property and equipment included in accounts payable	98	209
Lease assets obtained in exchange for new financing lease liabilities		48,224
Lease assets obtained in exchange for new operating lease liabilities	$ 1,580	5,152
Adjustment for non-cash lease termination		$ 177

Nature of the business	12 Months Ended
Nature of the business	Mar. 31, 2021
Nature of the business
Nature of the business	1. 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 $80,870 and -$52,625 for the years ended March 31, 2021 and 2020, respectively. In addition, as of March 31, 2021, the Company had an accumulated deficit of $193,168 . 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 disruptions 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 implementing work-from-home policies for the Company's employees, other than those in its laboratory, those performing manufacturing functions and certain other employees as deemed appropriate from time to time. For those employees, the Company has implemented stringent safety measures designed to comply with applicable federal, state and local guidelines instituted in response to the COVID-19 pandemic. 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 temporary closures of its suppliers and disruptions or restrictions on its employees’ ability to travel. Any prolonged material disruption to the Company’s employees or suppliers 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, 2021

Summary of significant accounting policies

Summary of significant accounting policies

2. 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 for the years ended March 31, 2021 and 2020, respectively. As of March 31, 2021 and 2020, the amount of cash equivalents included in cash and cash equivalents totaled $150,734 and $36,712, respectively.

Restricted cash

The Company holds restricted cash in segregated bank accounts in connection with a letter of credit. As of March 31, 2021 and 2020, 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 income (loss) in stockholders’ equity (deficit). 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 debt security investments as of March 31, 2021 and 2020 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		3 years
Plant, plant 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 cancelable, 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 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 $2,807 and $3,084 during the years ended March 31, 2021 and 2020, respectively, in the consolidated statements of operations and a research and development incentives receivable of $2,953 and $2,962 as of March 31, 2021 and 2020, respectively, on the consolidated balance sheets.

Comprehensive loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. 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. For the year ended March 31, 2020, comprehensive loss included $(236) of foreign currency translation adjustments and $309 of unrealized gains 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

The Company follows the two‑class method when computing net income (loss) per share as the Company has issued shares that meet the definition of participating securities. The two‑class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two‑class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed.

Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) attributable to common stockholders is computed by adjusting net income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net income (loss) per share attributable to common stockholders is computed by dividing the diluted net income (loss) attributable to common stockholders 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 attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.

Recently adopted accounting pronouncements

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820), Disclosure Framework- Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”). The amendments in this ASU require certain existing disclosure requirements in Topic 820 to be modified or removed, and certain new disclosure requirements to be added to the Topic. In addition, this ASU allows entities to exercise more discretion when considering fair value measurement disclosures. The Company adopted ASU 2018-13 on April 1, 2020. The adoption of ASU 2018-13 did not have a material impact on the Company's consolidated financial statements.

In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 (“ASU 2018-18”), which clarifies that certain transactions between collaborative arrangement participants should be accounted for as revenue under Topic 606 when the collaborative arrangement participant is a customer in the context of a unit of account.

In those situations, all the guidance in Topic 606 should be applied, including recognition, measurement, presentation, and disclosure requirements. The standard adds unit-of-account guidance in Topic 808 to align with the guidance in Topic 606 (that is, a distinct good or service) when an entity is assessing whether the collaborative arrangement or a part of the arrangement is within the scope of Topic 606, and requires that in a transaction with a collaborative arrangement participant that is not directly related to sales to third parties, presenting the transaction together with revenue recognized under Topic 606 is precluded if the collaborative arrangement participant is not a customer. The standard is effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted, including adoption in any interim period for public business entities for periods in which financial statements have not been issued. Amendments in the standard should be applied retrospectively to the date of initial application of Topic 606, but entities may elect to apply the amendments in this Update retrospectively either to all contracts or only to contracts that are not completed at the date of initial application of Topic 606, and should disclose the election. An entity may also elect to apply the practical expedient for contract modifications that is permitted for entities using the modified retrospective transition method in Topic 606. The Company adopted ASU 2018-18 on April 1, 2020. The adoption of ASU 2018-18 did not have a material impact on the Company's 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. 2019-04, 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. 2019-05, 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.

In December 2019, the FASB issued ASU No. 2019-12 Income Taxes (Topic 740) — Simplifying the Accounting for Income Taxes (ASU 2019-12), as part of its initiative to reduce complexity in the accounting standards. The amendments in ASU 2019-12 eliminates 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 clarifies and simplifies other aspects of the accounting for income taxes. The standard is effective for fiscal years and interim periods beginning after December 15, 2020. The Company is currently evaluating the impact of this new guidance on its financial statements and related disclosures but does not expect the adoption of ASU 2019-12 to have a material impact on the Company’s consolidated financial statements.

Fair value of financial assets and liabilities

12 Months Ended

Mar. 31, 2021

Fair value of financial assets and liabilities

Fair value of financial assets and liabilities

3. 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, 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


	Fair Value Measurements
	as of March 31, 2020 Using:
	Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	—	$	36,712	$	—	$	36,712
Commercial paper		—		21,884		—		21,884
US Treasury bonds		—		35,810		—		35,810
US Government Agency bonds		—		15,295		—		15,295
Corporate debt securities		—		36,066		—		36,066
	$	—	$	145,767	$	—	$	145,767

The underlying securities held in the money market funds held by the Company are all government backed securities. During the years ended March 31, 2021 and 2020, there were no transfers between levels.

Valuation of cash equivalents and short‑term investments

Money market funds, commercial paper, U.S. Treasury bonds, U.S. Government Agency bonds and corporate debt securities 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, 2021 and March 31, 2020.

- 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, 2021

Short-term investments

Short-term investments

4. Short‑term investments

Short‑term investments by investment type consisted of the following:


	March 31, 2021
			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		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


	March 31, 2020
			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		losses		Fair value
Commercial paper	$	21,818	$	66	$	—	$	21,884
US Government agency bonds		15,217		78		—		15,295
US Treasury bonds		35,590		220		—		35,810
Corporate debt securities		36,107		24		(65)		36,066
	$	108,732	$	388	$	(65)	$	109,055

Property, plant and equipment, net

12 Months Ended

Mar. 31, 2021

Property, plant and equipment, net

Property, plant and equipment, net

5. Property, plant and equipment, net

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


	March 31,		March 31,
	2021		2020
Office equipment	$	830	$	721
Computer equipment		1,695		1,658
Plant and laboratory equipment		6,369		3,669
Leasehold improvements		784		532
Construction in progress		412		1,217
		10,090		7,797
Less: Accumulated depreciation and amortization		(2,648)		(937)
	$	7,442	$	6,860

Depreciation and amortization expense was $1.7 million and $0.5 million for the years ended March 31, 2021 and 2020, respectively, and recorded within research and development and general and administrative expenses in the consolidated statement of operations.

Accrued expenses and other current liabilities

12 Months Ended

Mar. 31, 2021

Accrued expenses and other current liabilities

Accrued expenses and other current liabilities

6. Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following:


	March 31,		March 31,
	2021		2020
Accrued research and development costs	$	3,862	$	2,009
Accrued compensation and benefits costs		3,952		2,065
Accrued professional fees		407		779
Other		514		303
	$	8,735	$	5,156

Long-term debt

12 Months Ended

Mar. 31, 2021

Long-term debt

Long-term debt

7. Long-term debt

Long-term debt consisted of the following:


	March 31,		March 31,
	2021		2020

Principal amount of long-term debt	$	—	$	10,000
Unamortized debt discount		—		(199)
Long-term debt, net of discount	$	—	$	9,801

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 of upfront fees, including closing costs and legal fees associated with entering into the agreement, which were recorded as a debt discount. In connection with entering into the Hercules First Amendment, the Company paid $100 of upfront fees, including closing costs and legal fees associated with entering into the amendment, which were recorded as debt discount. The debt discount is reflected as a reduction of the carrying value of long-term debt on the Company's consolidated balance sheet for the year ended March 31, 2020.

The Company recognized aggregate interest expense under the Hercules Loan Agreement of $818 and $734 during the years ended March 31, 2021 and 2020, respectively, which included non-cash interest expense of $181 and $156. Non-cash interest expense included the amortization of the debt discount of $82 and $60, and the accretion of the final payment of $99 and $96, respectively, for the years ended March 31, 2021 and 2020.

There were no principal payments due or paid under the Hercules Loan Agreement during the year ended March 31, 2021.

Stockholders' equity	12 Months Ended
Stockholders' equity	Mar. 31, 2021
Stockholders' equity
Stockholders' equity	8. Stockholders’ Equity Common stock As of March 31, 2021 and 2020, 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, 2021 and 2020, the Company had reserved 14,572,115 and 10,449,033 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, 2021, 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, 2021. 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 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, if any. The Company has also agreed to provide the Agent with customary indemnification rights. During the year ended March 31, 2020, the Company issued and sold 287,559 shares, respectively, of common stock under the 2019 Sales Agreement, for gross proceeds of $4,568 less offering fees of $137 for net proceeds of $4,431 under the ATM . The Company did not issue or sell any shares under the 2020 Sales Agreement during the year ended March 31, 2021. 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 10 to these consolidated financial statements, including in the calculation of basic and diluted net loss per share attributable to common stockholders, the 5,284,238 shares of the Company’s common stock into which the November 2019 Pre-Funded Warrants, the June 2020 Pre-Funded Warrants and October 2020 Pre-Funded Warrants are exercisable are not included in the number of issued and outstanding shares of the Company’s common stock set forth herein. As of March 31, 2021, none of the November 2019 Pre-Funded Warrants, the June 2020 Pre-Funded Warrants, or the October 2020 Pre-Funded Warrants had been exercised.

Stock-based compensation

12 Months Ended

Mar. 31, 2021

Stock-based compensation

Stock-based compensation

9. 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, 2021 and 2020 as follows:


	Twelve Months Ended
	March 31,
	2021		2020
Research and development	$	5,749	$	3,689
General and administrative		6,041		4,052
	$	11,790	$	7,741

The following table summarizes stock-based compensation expense by award type for the years ended March 31, 2021 and 2020 as follows:


	Twelve Months Ended
	March 31,
	2021		2020
Stock options	$	11,778	$	7,741
Restricted stock units		12		—
	$	11,790	$	7,741

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 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 will be made under the 2015 Plan and any outstanding awards under the 2015 Plan 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 may be granted only to the Company’s employees, including officers and directors who are also employees. Restricted stock awards and non‑statutory stock options may be granted 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, 2021. 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 2017 Plan. 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, or such lesser amount as determined by the Board. 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. On April 1, 2019, the number of shares reserved for issuance under the 2018 Plan automatically increased by 1,266,278 shares pursuant to the terms of the 2018 Plan. As of March 31, 2021, 1,282,506 shares remained available for future grants under the 2018 Plan.

The 2015 Plan, the 2017 Plan and the 2018 Plan was 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, or 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 roughly equal installments on the approximate anniversary date of the date of grant.

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 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, on April 1, 2020 and 2019, the number of shares reserved for issuance under the ESPP automatically increased by 366,687 and 316,569 shares, respectively, for a total of 1,031,868 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.

Stock option valuation

The fair value of stock option grants is estimated using the Black-Scholes option-pricing model. The Company lacks company-specific historical and implied volatility information. Therefore, it estimated its expected stock volatility based on 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 estimated grant-date fair value of the Company’s stock options issued to employees was calculated using the Black-Scholes option-pricing model. The following table presents, on a weighted-average basis, the assumptions used in the Black-Scholes model, for the stock options granted to employees and directors:


	Twelve Months Ended
	March 31,
	2021		2020
Risk-free interest rate	0.93	%	2.12	%
Expected term (in years)	6.3		6.0
Expected volatility	75.4	%	71.4	%
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, 2021 is as follows:


		Weighted		Weighted Average
	Number of	Average		Contractual Term	Aggregate
	Shares	Exercise Price		(Years)	Intrinsic Value
Outstanding as of March 31, 2020	4,964,381	$	9.78	8.03	$	15,345
Granted	2,622,519		18.10	9.22
Exercised	(794,477)		7.23	6.41	$	24,859
Cancelled	(332,239)		14.00
Outstanding as of March 31, 2021	6,460,184		13.26	7.95	$	116,193
Options exercisable as of March 31, 2020	2,117,721	$	5.67	7.20	$	11,733
Options exercisable as of March 31, 2021	2,698,708	$	8.38	6.79	$	59,717

As of March 31, 2021 and 2020, there was $35.6 million and $18.7 million of unrecognized compensation cost related to unvested common stock options, which is expected to be recognized over a weighted average period of 3.00 years.

The weighted average grant-date fair value of stock options granted during the years ended March 31, 2021 and 2020 was $12.03 and $9.70, respectively. The total fair value of options vested during the years ended March 31, 2021 and 2020 was $10,182 and $5,440, respectively. The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company's common stock for those stock options that had exercise prices lower than the fair value of the Company's common stock. The intrinsic value of stock options exercised during the years ended March 31, 2021 and 2020 was $24.9 million and $2.3 million, respectively.

Restricted stock units

During the year ended March 31, 2021, the Company instituted RSU awards as a component of its overall employee benefit program and granted its first RSU award to a member of the executive team, which included 15,975 shares at an average grant date fair value of $34.15 per share. These RSUs vest in four substantially equal installments beginning approximately on the first anniversary of the grant date and continuing on each of the next three anniversaries thereof, subject to the employee’s continued employment with, or services to, the Company on each vesting date. Each RSU represents the right to receive one share of the Company’s common stock when and if the applicable vesting conditions are satisfied.

A summary of the changes in the Company’s RSUs during the year ended March 31, 2021 is as follows:


		Weighted
	Number of	Average
	Restricted	Grant Date
	Shares	Fair Value
Outstanding as of March 31, 2020	—	$	—
Granted	15,975		34.15
Vested	—		—
Cancelled	—		—
Outstanding as of March 31, 2021	15,975		34.15

At March 31, 2021 there was $0.5 million of total unrecognized compensation cost related to unvested RSUs, which will be recognized over a weighted-average period of 3.9 years. There was no unrecognized compensation cost related to unvested RSUs as of March 31, 2020.

Net loss per share

12 Months Ended

Mar. 31, 2021

Net loss per share

Net loss per share

10. 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,
	2021		2020
Numerator:
Net loss attributable to common stockholders	$	(80,870)	$	(52,625)
Denominator:
Weighted average common shares outstanding, basic and diluted		46,248,969		34,261,548
Net loss per share attributable to common stockholders, basic and diluted	$	(1.75)	$	(1.54)

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 attributable to common stockholders.

The Company's potentially dilutive securities, which include stock options and warrants to purchase shares of series seed preferred 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 attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:


	Twelve Months Ended
	March 31,
	2021	2020
Options to purchase common stock	6,476,159	4,964,381
Warrants to purchase convertible preferred stock (as converted to common stock)	497,344	497,344
	6,973,503	5,461,725

Significant agreements	12 Months Ended
Significant agreements	Mar. 31, 2021
Significant agreements
Significant agreements	11. 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 (i) in the event of an uncured material breach by the other party, (ii) in the event the other party is insolvent or in bankruptcy proceedings or (iii) 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, 2021 and 2020, the Company did not make any payments under the terms of the agreement from Regeneron. During the years ended March 31, 2021 and 2020, the Company received payments under the terms of the agreement from Regeneron of $5.1 million and $3.0 million, respectively. As of March 31, 2021 and 2020, the Company recorded $1.3 million and $971 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, 2021

Commitments and contingencies

Commitments and contingencies

12. 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.

The Company’s leases have remaining lease terms of eight years to eighteen 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 assets and liabilities recorded on the consolidated balance sheet as of March 31, 2021:


	Twelve Months Ended
	March 31,
	2021		2020
Lease cost
Finance lease costs:
Amortization of right-to-use asset	$	2,428	$	1,274
Interest on lease liabilities		2,242		1,185
Operating lease costs		948		885
Total lease cost	$	5,618	$	3,344

For the years ended March 31, 2021 and 2020, the Company incurred finance lease amortization costs of $2,428 and $1,274, respectively, of which $2,070 and $1,034 are recognized in research and development expenses. In addition, the Company incurred interest expense on finance leases of $2,242 and $1,185, of which $1,881 and $944 are recognized in research and development expenses for the years ended March 31, 2021 and 2020, respectively. For the years ended March 31, 2021 and 2020, the Company recognized $948 and $885, respectively, of operating lease costs within general and administrative expenses. 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, 2021:


	March 31, 2021
	Operating leases		Financing lease		Total
2022	$	970	$	2,487	$	3,457
2023		980		2,562		3,542
2024		989		2,639		3,628
2025		998		2,718		3,716
2026		1,008		2,799		3,807
Thereafter		4,066		40,905		44,971
Total lease payments		9,011		54,110		63,121
Less: interest		2,963		26,878		29,841
Total lease liabilities	$	6,048	$	27,232	$	33,280

The following table provides lease disclosure as of and for the year ended March 31, 2021:


	March 31, 2021			March 31, 2020
Leases
Right-to-use operating lease asset	$	5,751		$	4,425
Right-to-use finance lease asset		44,522			46,925
Total lease assets	$	50,273		$	51,350

Operating lease liabilities, current	$	970		$	873
Finance lease liabilities, current		2,487			2,411
Operating lease liabilities, non-current		5,078			3,737
Finance lease liabilities, non-current		24,745			24,967
Total lease liabilities	$	33,280		$	31,988
Other information
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	823		$	747
Operating cash flows from finance leases	$	2,240		$	1,185
Financing cash flows from finance leases	$	145		$	59
Right-to-use asset obtained in exchange for new operating lease liabilities				$	5,152
Right-to-use asset obtained in exchange for new financing lease liabilities	$	—		$	48,224
Weighted-average remaining lease term-operating leases		8.9 years			8.7 years
Weighted-average remaining lease term-financing leases		18.3 years			19.3 years
Weighted-average discount rate-operating leases		9.8	%		7	%
Weighted-average discount rate-financing leases		8.3	%		8	%

The variable lease costs and short-term lease costs were insignificant for the years ended March 31, 2021 and 2020, respectively.

Manufacturing commitments

The Company has entered into an agreement with a contract manufacturing organization to provide clinical trial products. As of March 31, 2021 and 2020, the Company had committed to minimum payments under these arrangements totaling $1,651 and $3,569 through March 31, 2021.

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, 2021 or 2020.

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, 2021
Benefit plans
Benefit plans	13. 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, 2021 and 2020, the Company made contributions totaling $723 and $232, 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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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

+ Details

Income taxes

12 Months Ended

Mar. 31, 2021

Income taxes

Income taxes

14. Income taxes

On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) was enacted in the United States. The CARES Act provides numerous tax provisions and other stimulus measures, including temporary changes regarding the prior and future utilization of net operating losses and technical corrections from prior tax legislation for tax depreciation of certain qualified improvement property. We evaluated the provisions of the CARES Act and do not anticipate the associated impacts, if any, will have a material effect on our financial position.

During the years ended March 31, 2021 and 2020, 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, 2021 and 2020 were as follows:

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, 2021 and 2020 is as follows:


	Year Ended March 31,
	2021		2020
U.S. Federal statutory income tax rate	(21.0)	%	(21.0)	%
State taxes, net of federal benefit	(2.4)	%	(1.6)	%
Research and development credits	(0.8)	%	0	%
Research and development expenses	1.9	%	2.2	%
Return to provision	0	%	1.9	%
Stock compensation	(3.9)	%	0	%
Foreign tax rate differential	0.0	%	2.8	%
Change in valuation allowance	25.9	%	16.0	%
Other	0.3	%	(0.3)	%
	0.0	%	0.00	%

Components of the Company’s deferred tax assets as of March 31, 2021 and 2020 were as follows:


	Year Ended March 31,
	2021		2020
Deferred tax assets
Federal net operating loss carryforwards		7,083		2,450
Foreign net operating loss carryforwards		22,195		9,092
State net operating loss carryforwards		2,358		1,054
Research & development credits		787		—
Property, plant and equipment		5,068		5,499
Capitalized start-up costs		1,597		1,748
Stock compensation		4,838		2,526
Accrued expense		739		341
Lease liability		8,462		8,705
Total deferred tax assets		53,127		31,415
Deferred tax liabilities
Right of Use Asset		(13,090)		(13,998)
Other		(9)		(88)
Total deferred tax liabilities		(13,099)		(14,086)
Valuation Allowance		(40,028)		(17,329)
Net deferred tax assets		—		—

As of March 31, 2021, the Company had federal and foreign net operating loss carryforwards of approximately $33,731 and $116,815, respectively, which can be carried forward indefinitely. As of March 31, 2021, the Company had state net operating loss carryforwards of $37,311, which will begin to expire in 2039.

As of March 31, 2021, the Company had federal and state research and development carryforwards of approximately $687 and $126, 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, 2021 and 2020 related primarily to the increase in net operating loss carryforwards were as follows:


	Year Ended March 31,
	2021		2020
Valuation allowance as of beginning of year	$	17,329	$	9,396
Increases recorded to income tax provision		22,624	$	8,047
Increases recorded to income tax provision for equity	$	76	$	—
Decreases recorded to income tax provision for equity	$	—	$	(114)
Valuation allowance as of end of year		40,028	$	17,329

As of March 31, 2021 and 2020, 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, 2021 and 2020, 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 2018 to the present and in the United Kingdom from 2017 to the present.

As of March 31, 2021 and 2020, 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.

- 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 + Details

Geographic information

12 Months Ended

Mar. 31, 2021

Geographic information

Geographic information

15. 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, 2021		March 31, 2020
United States	$	6,866	$	6,357
United Kingdom		576		503
	$	7,442	$	6,860

Quarterly financial data (unaudited)

12 Months Ended

Mar. 31, 2021

Quarterly financial data (unaudited)

Quarterly financial data (unaudited)

16. Quarterly financial data (unaudited)

The following information has been derived from unaudited consolidated financial statements that, in the opinion of management, include all recurring adjustments necessary for a fair statement of such information.


	Three Months Ended
	March 31, 2021	December 31, 2020	September 30, 2020	June 30, 2020
Operating Expenses	22,184	20,275	19,663	17,833
Net loss attributable to common stockholders	(21,499)	(21,783)	(20,095)	(17,493)
Net loss per share attributable to common stockholders, basic and diluted	(0.42)	(0.44)	(0.46)	(0.44)


	Three Months Ended
	March 31, 2020	December 31, 2019	September 30, 2019	June 30, 2019
Operating Expenses	16,385	16,664	12,242	10,907
Net loss attributable to common stockholders	(15,789)	(16,189)	(11,139)	(9,508)
Net loss per share attributable to common stockholders, basic and diluted	(0.41)	(0.46)	(0.35)	(0.30)

Summary of significant accounting policies (Policies)

12 Months Ended

Mar. 31, 2021

Summary of significant accounting policies

Principles of consolidation

Use of estimates

Foreign currency and currency translation

Concentrations of credit risk and of significant suppliers

Cash and cash equivalents

Restricted cash

Short-term investments

Short‑term investments

The Company’s short‑term debt security investments as of March 31, 2021 and 2020 had maturities of less than two years.

Property, plant and equipment


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

Impairment of long-lived assets

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

Stock‑based compensation

Research and development incentives and receivable

Comprehensive loss

Income taxes

Net income (loss) per share

Recently adopted accounting pronouncements

Recently issued accounting pronouncements

Summary of significant accounting policies (Tables)

12 Months Ended

Mar. 31, 2021

Summary of significant accounting policies

Schedule of estimated useful life of property, plant and equipment


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

Fair value of financial assets and liabilities (Tables)

12 Months Ended

Mar. 31, 2021

Fair value of financial assets and liabilities

Schedule of company's financial assets and liabilities measured at fair value on a recurring basis

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


	Fair Value Measurements
	as of March 31, 2020 Using:
	Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	—	$	36,712	$	—	$	36,712
Commercial paper		—		21,884		—		21,884
US Treasury bonds		—		35,810		—		35,810
US Government Agency bonds		—		15,295		—		15,295
Corporate debt securities		—		36,066		—		36,066
	$	—	$	145,767	$	—	$	145,767

Short-term investments (Tables)

12 Months Ended

Mar. 31, 2021

Short-term investments

Schedule of short-term investments


	March 31, 2021
			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		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


	March 31, 2020
			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		losses		Fair value
Commercial paper	$	21,818	$	66	$	—	$	21,884
US Government agency bonds		15,217		78		—		15,295
US Treasury bonds		35,590		220		—		35,810
Corporate debt securities		36,107		24		(65)		36,066
	$	108,732	$	388	$	(65)	$	109,055

Property, plant and equipment, net (Tables)

12 Months Ended

Mar. 31, 2021

Property, plant and equipment, net

Schedule of property, plant and equipment, net


	March 31,		March 31,
	2021		2020
Office equipment	$	830	$	721
Computer equipment		1,695		1,658
Plant and laboratory equipment		6,369		3,669
Leasehold improvements		784		532
Construction in progress		412		1,217
		10,090		7,797
Less: Accumulated depreciation and amortization		(2,648)		(937)
	$	7,442	$	6,860

Accrued expenses and other current liabilities (Tables)

12 Months Ended

Mar. 31, 2021

Accrued expenses and other current liabilities

Schedule of accrued expenses and other current liabilities


	March 31,		March 31,
	2021		2020
Accrued research and development costs	$	3,862	$	2,009
Accrued compensation and benefits costs		3,952		2,065
Accrued professional fees		407		779
Other		514		303
	$	8,735	$	5,156

Long-term debt (Tables)

12 Months Ended

Mar. 31, 2021

Long-term debt

Schedule of long-term debt


	March 31,		March 31,
	2021		2020

Principal amount of long-term debt	$	—	$	10,000
Unamortized debt discount		—		(199)
Long-term debt, net of discount	$	—	$	9,801

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Subparagraph (SX 210.4-08.(e),(f))
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 505
-SubTopic 10
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-Paragraph 3
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+ Details

Stock-based compensation (Tables)

12 Months Ended

Mar. 31, 2021

Stock-based Compensation

Summary of stock option activity


		Weighted		Weighted Average
	Number of	Average		Contractual Term	Aggregate
	Shares	Exercise Price		(Years)	Intrinsic Value
Outstanding as of March 31, 2020	4,964,381	$	9.78	8.03	$	15,345
Granted	2,622,519		18.10	9.22
Exercised	(794,477)		7.23	6.41	$	24,859
Cancelled	(332,239)		14.00
Outstanding as of March 31, 2021	6,460,184		13.26	7.95	$	116,193
Options exercisable as of March 31, 2020	2,117,721	$	5.67	7.20	$	11,733
Options exercisable as of March 31, 2021	2,698,708	$	8.38	6.79	$	59,717

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, 2021 and 2020 as follows:


	Twelve Months Ended
	March 31,
	2021		2020
Research and development	$	5,749	$	3,689
General and administrative		6,041		4,052
	$	11,790	$	7,741

The following table summarizes stock-based compensation expense by award type for the years ended March 31, 2021 and 2020 as follows:


	Twelve Months Ended
	March 31,
	2021		2020
Stock options	$	11,778	$	7,741
Restricted stock units		12		—
	$	11,790	$	7,741

Summary of changes in company's RSU


		Weighted
	Number of	Average
	Restricted	Grant Date
	Shares	Fair Value
Outstanding as of March 31, 2020	—	$	—
Granted	15,975		34.15
Vested	—		—
Cancelled	—		—
Outstanding as of March 31, 2021	15,975		34.15

Stock options

Stock-based Compensation

Schedule of assumptions used to determine the grant-date fair value of stock options granted


	Twelve Months Ended
	March 31,
	2021		2020
Risk-free interest rate	0.93	%	2.12	%
Expected term (in years)	6.3		6.0
Expected volatility	75.4	%	71.4	%
Expected dividend yield	0	%	0	%

Net loss per share (Tables)

12 Months Ended

Mar. 31, 2021

Net loss per share

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,
	2021		2020
Numerator:
Net loss attributable to common stockholders	$	(80,870)	$	(52,625)
Denominator:
Weighted average common shares outstanding, basic and diluted		46,248,969		34,261,548
Net loss per share attributable to common stockholders, basic and diluted	$	(1.75)	$	(1.54)

Schedule of anti-dilutive securities excluded from the computation of diluted net loss per share attributable to common shareholders


	Twelve Months Ended
	March 31,
	2021	2020
Options to purchase common stock	6,476,159	4,964,381
Warrants to purchase convertible preferred stock (as converted to common stock)	497,344	497,344
	6,973,503	5,461,725

Commitments and contingencies (Tables)

12 Months Ended

Mar. 31, 2021

Commitments and contingencies

Schedule of variable lease components


	Twelve Months Ended
	March 31,
	2021		2020
Lease cost
Finance lease costs:
Amortization of right-to-use asset	$	2,428	$	1,274
Interest on lease liabilities		2,242		1,185
Operating lease costs		948		885
Total lease cost	$	5,618	$	3,344

Summary of the maturity of company's lease liabilities


	March 31, 2021
	Operating leases		Financing lease		Total
2022	$	970	$	2,487	$	3,457
2023		980		2,562		3,542
2024		989		2,639		3,628
2025		998		2,718		3,716
2026		1,008		2,799		3,807
Thereafter		4,066		40,905		44,971
Total lease payments		9,011		54,110		63,121
Less: interest		2,963		26,878		29,841
Total lease liabilities	$	6,048	$	27,232	$	33,280

Schedule of additional information related to leases


	March 31, 2021			March 31, 2020
Leases
Right-to-use operating lease asset	$	5,751		$	4,425
Right-to-use finance lease asset		44,522			46,925
Total lease assets	$	50,273		$	51,350

Operating lease liabilities, current	$	970		$	873
Finance lease liabilities, current		2,487			2,411
Operating lease liabilities, non-current		5,078			3,737
Finance lease liabilities, non-current		24,745			24,967
Total lease liabilities	$	33,280		$	31,988
Other information
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	823		$	747
Operating cash flows from finance leases	$	2,240		$	1,185
Financing cash flows from finance leases	$	145		$	59
Right-to-use asset obtained in exchange for new operating lease liabilities				$	5,152
Right-to-use asset obtained in exchange for new financing lease liabilities	$	—		$	48,224
Weighted-average remaining lease term-operating leases		8.9 years			8.7 years
Weighted-average remaining lease term-financing leases		18.3 years			19.3 years
Weighted-average discount rate-operating leases		9.8	%		7	%
Weighted-average discount rate-financing leases		8.3	%		8	%

Income taxes (Tables)

12 Months Ended

Mar. 31, 2021

Income taxes

Schedule of net loss before income taxes

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


	Year Ended March 31,
	2021		2020
U.S. Federal statutory income tax rate	(21.0)	%	(21.0)	%
State taxes, net of federal benefit	(2.4)	%	(1.6)	%
Research and development credits	(0.8)	%	0	%
Research and development expenses	1.9	%	2.2	%
Return to provision	0	%	1.9	%
Stock compensation	(3.9)	%	0	%
Foreign tax rate differential	0.0	%	2.8	%
Change in valuation allowance	25.9	%	16.0	%
Other	0.3	%	(0.3)	%
	0.0	%	0.00	%

Schedule of components of deferred tax assets and liabilities


	Year Ended March 31,
	2021		2020
Deferred tax assets
Federal net operating loss carryforwards		7,083		2,450
Foreign net operating loss carryforwards		22,195		9,092
State net operating loss carryforwards		2,358		1,054
Research & development credits		787		—
Property, plant and equipment		5,068		5,499
Capitalized start-up costs		1,597		1,748
Stock compensation		4,838		2,526
Accrued expense		739		341
Lease liability		8,462		8,705
Total deferred tax assets		53,127		31,415
Deferred tax liabilities
Right of Use Asset		(13,090)		(13,998)
Other		(9)		(88)
Total deferred tax liabilities		(13,099)		(14,086)
Valuation Allowance		(40,028)		(17,329)
Net deferred tax assets		—		—

Schedule of changes in the valuation allowance for deferred tax assets


	Year Ended March 31,
	2021		2020
Valuation allowance as of beginning of year	$	17,329	$	9,396
Increases recorded to income tax provision		22,624	$	8,047
Increases recorded to income tax provision for equity	$	76	$	—
Decreases recorded to income tax provision for equity	$	—	$	(114)
Valuation allowance as of end of year		40,028	$	17,329

Geographic information (Tables)

12 Months Ended

Mar. 31, 2021

Geographic information

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


	March 31, 2021		March 31, 2020
United States	$	6,866	$	6,357
United Kingdom		576		503
	$	7,442	$	6,860

Quarterly financial data (unaudited) (Tables)

12 Months Ended

Mar. 31, 2021

Quarterly financial data (unaudited)

Schedule of Quarterly financial information


	Three Months Ended
	March 31, 2021	December 31, 2020	September 30, 2020	June 30, 2020
Operating Expenses	22,184	20,275	19,663	17,833
Net loss attributable to common stockholders	(21,499)	(21,783)	(20,095)	(17,493)
Net loss per share attributable to common stockholders, basic and diluted	(0.42)	(0.44)	(0.46)	(0.44)


	Three Months Ended
	March 31, 2020	December 31, 2019	September 30, 2019	June 30, 2019
Operating Expenses	16,385	16,664	12,242	10,907
Net loss attributable to common stockholders	(15,789)	(16,189)	(11,139)	(9,508)
Net loss per share attributable to common stockholders, basic and diluted	(0.41)	(0.46)	(0.35)	(0.30)

Nature of the business (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
Nature of the business (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020
Nature of the business
Net losses	$ 21,499	$ 21,783	$ 20,095	$ 17,493	$ 15,789	$ 16,189	$ 11,139	$ 9,508	$ 80,870	$ 52,625
Accumulated deficit	$ (193,168)				$ (112,298)				$ (193,168)	$ (112,298)

- Definition

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

+ References

+ Details

Summary of significant accounting policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Summary of significant accounting policies
Cash equivalents	$ 150,734	$ 36,712
Restricted cash	1,636	1,636
Research and Development Incentives Income	2,807	3,084
Research and Development Incentives Receivable, Current	2,953	2,962
Foreign currency translation gain (loss)	866	(236)
Unrealized loss on short-term investments, net of tax	$ (278)	309
Minimum percentage of benefit recognized is being realized upon ultimate settlement	50.00%
Office equipment
Summary of significant accounting policies
Property, Plant and Equipment, Useful Life	5 years
Computer equipment
Summary of significant accounting policies
Property, Plant and Equipment, Useful Life	3 years
Plant, plant and laboratory equipment
Summary of significant accounting policies
Property, Plant and Equipment, Useful Life	5 years
Leasehold improvements
Summary of significant accounting policies
Property, Plant and Equipment, Useful Life	10 years
United Kingdom \| Maximum
Summary of significant accounting policies
Percentage of qualifying research and development expenses reimbursed by government	14.50%
Operating Lease [Member]
Summary of significant accounting policies
Restricted cash	$ 1,636	$ 1,636

Fair value of financial assets and liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair value of financial assets and liabilities
Transfer from Leve 1 to Level 2, assets	$ 0	$ 0
Transfer from Leve 2 to Level 1, assets	0	0
Transfers into Level 3, assets	0	0
Transfer out of Level 3, assets	0	0
Transfer from Leve 1 to Level 2, liabilities	0	0
Transfer from Leve 2 to Level 1, liabilities	0	0
Transfers into Level 3, liabilities	0	0
Transfer out of Level 3, liabilities	0	0
Recurring
Fair value of financial assets and liabilities
Assets fair value	444,518	145,767
Level 2 \| Recurring
Fair value of financial assets and liabilities
Assets fair value	444,518	145,767
Money market funds \| Recurring
Fair value of financial assets and liabilities
Assets fair value	150,734	36,712
Money market funds \| Level 2 \| Recurring
Fair value of financial assets and liabilities
Assets fair value	150,734	36,712
Commercial paper \| Recurring
Fair value of financial assets and liabilities
Assets fair value		21,884
Commercial paper \| Level 2 \| Recurring
Fair value of financial assets and liabilities
Assets fair value		21,884
US Treasury bonds \| Recurring
Fair value of financial assets and liabilities
Assets fair value	226,772	35,810
US Treasury bonds \| Level 2 \| Recurring
Fair value of financial assets and liabilities
Assets fair value	226,772	35,810
US Government Agency bonds \| Recurring
Fair value of financial assets and liabilities
Assets fair value	67,012	15,295
US Government Agency bonds \| Level 2 \| Recurring
Fair value of financial assets and liabilities
Assets fair value	$ 67,012	15,295
Corporate debt securities \| Recurring
Fair value of financial assets and liabilities
Assets fair value		36,066
Corporate debt securities \| Level 2 \| Recurring
Fair value of financial assets and liabilities
Assets fair value		$ 36,066

Short-term investments (Details) - Short-term investments - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Short-term investments
Amortized cost	$ 293,739	$ 108,732
Gross unrealized gains	67	388
Gross unrealized losses	(22)	(65)
Fair value	293,784	109,055
Commercial paper
Short-term investments
Amortized cost		21,818
Gross unrealized gains		66
Fair value		21,884
US Government Agency bonds
Short-term investments
Amortized cost	67,017	15,217
Gross unrealized gains	12	78
Gross unrealized losses	(17)
Fair value	67,012	15,295
US Treasury bonds
Short-term investments
Amortized cost	226,722	35,590
Gross unrealized gains	55	220
Gross unrealized losses	(5)
Fair value	$ 226,772	35,810
Corporate debt securities
Short-term investments
Amortized cost		36,107
Gross unrealized gains		24
Gross unrealized losses		(65)
Fair value		$ 36,066

Property, plant and equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Property, plant and equipment, net
Property, plant and equipment , gross	$ 10,090	$ 7,797
Less: Accumulated depreciation and amortization	(2,648)	(937)
Property, plant and equipment , net	7,442	6,860
Depreciation and amortization expense	1,711	533
Office equipment
Property, plant and equipment, net
Property, plant and equipment , gross	830	721
Computer equipment
Property, plant and equipment, net
Property, plant and equipment , gross	1,695	1,658
Plant and laboratory equipment
Property, plant and equipment, net
Property, plant and equipment , gross	6,369	3,669
Leasehold improvements
Property, plant and equipment, net
Property, plant and equipment , gross	784	532
Construction in progress
Property, plant and equipment, net
Property, plant and equipment , gross	$ 412	$ 1,217

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Accrued expenses and other current liabilities
Accrued research and development costs	$ 3,862	$ 2,009
Accrued compensation and benefits costs	3,952	2,065
Accrued professional fees	407	779
Other	514	303
Total	$ 8,735	$ 5,156

Long-term debt (Details) $ in Thousands	Mar. 31, 2020 USD ($)
Long-term debt
Principal amount of long-term debt	$ 10,000
Unamortized debt discount	(199)
Long-term debt, net of discount	$ 9,801

Long-term debt - Hercules Loan Agreement (Details) - USD ($) $ in Thousands				12 Months Ended
	Dec. 15, 2020	Jun. 01, 2020	Aug. 08, 2019	Mar. 31, 2021	Mar. 31, 2020
Debt Securities
Loss on extinguishment of debt				$ (913)
Interest expense				818	$ 734
Noncash interest expense				181	156
Debt discount					199
Hercules Loan Agreement
Debt Securities
Maximum borrowing capacity			$ 30,000
Borrowed amount			10,000
Payment of issuance costs			225
Additional closing and legal fees			$ 130
Total paid amount	$ 10,839
Outstanding principal	10,000				0
Term charge	495
Termination fee due	300
Accrued interest	44
Unused borrowing capacity available under the facility		$ 30,000
Upfront fees, including closing costs and legal fees				355
Interest expense				818	734
Noncash interest expense				181	156
Accretion of the debt discount				82	60
Accretion of the final payment				99	96
Principal payments due or paid	10,000				$ 0
Hercules first amendment
Debt Securities
Additional closing and legal fees		100
Upfront fees, including closing costs and legal fees				$ 100
Hercules loan agreement, second advance
Debt Securities
Maximum borrowing capacity		40,000
Hercules loan agreement, third advance
Debt Securities
Maximum borrowing capacity		$ 10,000
Prime Rate \| Hercules Loan Agreement
Debt Securities
Loss on extinguishment of debt	$ 913

Stockholders' equity (Details) - $ / shares	Mar. 31, 2021	Mar. 31, 2020
Stockholders' Equity
Shares authorized (in shares)	150,000,000	150,000,000
Par value (in dollars per share)	$ 0.001	$ 0.001
Common stock
Stockholders' Equity
Common stock reserved for issuance	14,572,115	10,449,033
Undesignated preferred stock \| Initial public offering
Stockholders' Equity
Undesignated preferred stock, authorized	10,000,000
Preferred stock, Par Value (in dollars per share)	$ 0.001
Undesignated preferred shares issued	0
Undesignated preferred shares outstanding	0

Stockholders' equity - ATM Program (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended				12 Months Ended
	Aug. 11, 2020	Oct. 31, 2020	Jun. 30, 2020	Dec. 31, 2019	Aug. 31, 2019	Mar. 31, 2021	Mar. 31, 2020
Class of Warrant or Right [Line Items]
Common stock, par value (in dollars per share)						$ 0.001	$ 0.001
Issuance of stock (value)						$ 286,107
Net proceeds		$ 269,975	$ 107,782	$ 85,598
ATM sales
Class of Warrant or Right [Line Items]
Percentage Of Commission					3.00%
Issuance of stock (value)							$ 4,431
Shares issued during period							287,559
Gross proceeds							$ 4,568
Legal fees							137
Net proceeds							$ 4,431
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, 2021	Mar. 31, 2020
Class of Warrant or Right [Line Items]
Net proceeds from issuance after deducting underwriting discounts, commissions and other offering expenses	$ 269,975	$ 107,782	$ 85,598
Underwriting discounts, commissions and other offering expenses					$ 100	$ 355
Number of common stocks are exercisable from the November 2019 Pre-Funded Warrants and the June 2020 Pre-Funded Warrants					5,284,238
Pre-Funded Warrants
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	1,562,500	1,521,738
Public offering price	$ 39.9999	$ 22.9999		$ 13.6099
Variation between public offering prices of common stock and Pre-Funded Warrants	$ 0.0001	$ 0.0001		$ 0.0001
Maximum percentage of holding for exercise warrants	9.99%	9.99%		9.99%
Prior notice period to change percentage of holding	61 days	61 days
Maximum percentage of increase (decrease) of holding for exercise warrants	19.99%	19.99%
Underwriter rights
Class of Warrant or Right [Line Items]
Number of shares issued	5,625,000	3,478,261	838,530	4,516,561
Issuance of pre-funded warrants (in shares)				2,200,000
Public offering price	$ 40.00	$ 23.00		$ 13.61
Shares issued during period	937,500	652,173
Underwriting discounts, commissions and other offering expenses	$ 17,525
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 (Details) - shares				12 Months Ended
Stock-based compensation (Details) - shares	Apr. 01, 2020	Apr. 01, 2019	Jul. 09, 2018	Mar. 31, 2021
2017 Plan
Share based payments
Shares authorized (in shares)				2,659,885
Number of shares available for grant			2,520,247	0
2018 Plan
Share based payments
Shares authorized (in shares)			3,617,968
Number of shares available for grant				1,282,506
Additional shares authorized (in shares)	1,466,749	1,266,278
ESPP
Share based payments
Additional shares authorized (in shares)	366,687	316,569	697,224
Common stock reserved for issuance	1,031,868		348,612
Share based payment award percentage of outstanding shares			1.00%
Stock options
Share based payments
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
Stock options \| Minimum
Share based payments
Expiration period for persons holding more than ten percent of voting power				10 years
Stock options \| Maximum
Share based payments
Expiration period for persons holding ten percent of voting power				5 years
2018 Plan
Share based payments
Share based payment award percentage of outstanding shares			4.00%

Stock-based compensation - Classification of expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock-Based Compensation
Stock-based compensation expense	$ 11,790	$ 7,741
Stock options
Stock-Based Compensation
Stock-based compensation expense	11,778	7,741
Restricted stock units
Stock-Based Compensation
Stock-based compensation expense	12
Research and development expenses
Stock-Based Compensation
Stock-based compensation expense	5,749	3,689
General and administrative expenses
Stock-Based Compensation
Stock-based compensation expense	$ 6,041	$ 4,052

Stock-based compensation - Assumptions to determine grant-date fair value of stock options (Details) - Stock options	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock-based Compensation
Risk-free interest rate	0.93%	2.12%
Expected term (in years)	6 years 3 months 18 days	6 years
Expected volatility	75.40%	71.40%
Expected dividend yield	0.00%	0.00%

Stock-based compensation - Stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Number of Shares
Outstanding at beginning of the period (in shares)	4,964,381
Granted (in shares)	2,622,519
Exercised (in shares)	(794,477)
Cancelled (in shares)	(332,239)
Outstanding at end of the period (in shares)	6,460,184	4,964,381
Options exercisable (in shares)	2,698,708	2,117,721
Weighted Average Exercise Price
Outstanding at beginning of the period (in dollars per share)	$ 9.78
Granted (in dollars per share)	18.10
Exercised (in dollars per share)	7.23
Cancelled (in dollars per share)	14.00
Outstanding at end of the period (in dollars per share)	13.26	$ 9.78
Options exercisable (in dollars per share)	$ 8.38	$ 5.67
Weighted Average Contractual Term (Years)
Outstanding (years)	7 years 11 months 12 days	8 years 11 days
Granted (years)	9 years 2 months 19 days
Exercised (years)	6 years 4 months 28 days
Options exercisable (years)	6 years 9 months 15 days	7 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding at beginning of the period	$ 15,345
Exercised	24,859
Outstanding at end of the period	116,193	$ 15,345
Options exercisable	$ 59,717	$ 11,733
Weighted average grant-date fair value per share of stock options granted	$ 12.03	$ 9.70
Total fair value of options vested	$ 10,182	$ 5,440
Intrinsic value of stock options exercised	$ 24,900	2,300
Expenses expected to be recognized over a weighted average remaining period	3 years
Unrecognized compensation cost related to unvested common stock options	$ 35,600	$ 18,700

Stock-based compensation - Changes in company RSU (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Mar. 31, 2021 USD ($) $ / shares shares
Number of Restricted Shares
Ending balance (in shares) \| shares	15,975
Weighted Average Grant Date Fair Value
Ending balance (in dollars per share) \| $ / shares	$ 34.15
Weighted-average period	3 years
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
Number of Restricted Shares
Granted (in shares) \| shares	15,975
Weighted Average Grant Date Fair Value
Granted (in dollars per share) \| $ / shares	$ 34.15
Unrecognized compensation cost \| $	$ 0.5
Weighted-average period	3 years 10 months 24 days

Net loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net loss attributable to common stockholders									$ (80,870)	$ (52,625)
Denominator:
Weighted average common shares outstanding, basic and diluted (in shares)									46,248,969	34,261,548
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.42)	$ (0.44)	$ (0.46)	$ (0.44)	$ (0.41)	$ (0.46)	$ (0.35)	$ (0.30)	$ (1.75)	$ (1.54)

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1448-109256

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1377-109256

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

+ Details

Net loss per share - Computation of diluted net loss per share attributable to common stockholders (Details) - shares	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Diluted net loss per share attributable to common stockholders
Antidilutive securities excluded from computation of diluted weighted average shares outstanding	6,973,503	5,461,725
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	6,476,159	4,964,381
Warrants to purchase convertible preferred stock
Diluted net loss per share attributable to common stockholders
Antidilutive securities excluded from computation of diluted weighted average shares outstanding	497,344	497,344

Significant agreements (Details) $ in Thousands	1 Months Ended	12 Months Ended
Significant agreements (Details) $ in Thousands	Jan. 31, 2020 item	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)
Significant agreements
Prepaid expenses and other current assets		$ 4,492	$ 2,734
Regeneron Pharmaceuticals, Inc
Significant agreements
Payments received under the terms of the agreement		5,100	3,000
Prepaid expenses and other current assets		$ 1,300	$ 971
Bristol-Myers Squibb Company
Significant agreements
Number Of Patients \| item	125

Commitments and contingencies - Lease agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lease agreements
Property, plant and equipment, net	$ 7,442	$ 6,860
Right-to-use asset	5,751	4,425
Right-to-use liability	6,048
Finance lease Amortization	2,428	1,274
Interest on lease liabilities	2,242	1,185
Operating lease costs	948	885
General and administrative expenses
Lease agreements
Operating lease costs	948	885
Research and development expenses
Lease agreements
Finance lease Amortization	2,070	1,034
Interest on lease liabilities	$ 1,881	$ 944

Commitments and contingencies - Components of lease expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Finance lease costs:
Amortization of right-of-use assets	$ 2,428	$ 1,274
Interest on lease liabilities	2,242	1,185
Operating lease costs	948	885
Total lease cost	$ 5,618	$ 3,344

Commitments and contingencies - Future lease payments under operating and financing lease liabilities (Details) $ in Thousands	Mar. 31, 2021 USD ($)
Operating lease
2022	$ 970
2023	980
2024	989
2025	998
2026	1,008
Thereafter	4,066
Total lease payments	9,011
Less: interest	2,963
Total lease liabilities	6,048
Financing lease
2022	2,487
2023	2,562
2024	2,639
2025	2,718
2026	2,799
Thereafter	40,905
Total lease payments	54,110
Less: interest	26,878
Total lease liabilities	27,232
Total
2022	3,457
2023	3,542
2024	3,628
2025	3,716
2026	3,807
Thereafter	44,971
Total lease payments	63,121
Less: interest	29,841
Total lease liabilities	$ 33,280

Commitments and contingencies - Additional information related to leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases
Right-to-use operating lease asset	$ 5,751	$ 4,425
Right-to-use finance lease asset	44,522	46,925
Total lease assets	50,273	51,350
Operating lease liabilities, current	970	873
Finance lease liabilities, current	2,487	2,411
Operating lease liabilities, non-current	5,078	3,737
Financing lease liabilities, non-current	24,745	24,967
Total lease liabilities	33,280	31,988
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	823	747
Operating cash flows from finance leases	2,240	1,185
Financing cash flows from finance leases	145	59
Right-to-use asset obtained in exchange for new operating lease liabilities	$ 1,580	5,152
Right-to-use asset obtained in exchange for new financing lease liabilities		$ 48,224
Weighted-average remaining lease term - operating leases	8 years 10 months 24 days	8 years 8 months 12 days
Weighted-average remaining lease term - financing leases	18 years 3 months 18 days	19 years 3 months 18 days
Weighted-average discount rate - operating leases	9.80%	7.00%
Weighted-average discount rate - financing leases	8.30%	8.00%

Commitments and contingencies - Manufacturing commitments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Commitments and contingencies
Minimum payments committed to manufacturing organization	$ 1,651	$ 3,569

Benefit plans (Details) - USD ($) $ in Thousands	12 Months Ended
Benefit plans (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
401(k) Plan
Benefit Plans
Contributions to the plan	$ 723	$ 232
Pension Plan
Benefit Plans
Maximum percentage of contribution by employee of their annual base salary	8.00%

Income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income taxes (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Income Taxes
Income tax benefit	$ 0	$ 0
Net loss before income taxes
United States	(22,775)	(12,963)
Foreign (United Kingdom)	(58,095)	(39,662)
Net loss before income taxes	$ (80,870)	$ (52,625)

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Income taxes - Reconciliation of the U.S federal statutory income tax rate (Details)	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
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	(2.40%)	(1.60%)
Research and development credits	(0.80%)	0.00%
Research and development expenses	1.90%	2.20%
Return to provision	0.00%	1.90%
Stock compensation	(3.90%)	0.00%
Foreign tax rate differential	0.00%	2.80%
Change in valuation allowance	25.90%	16.00%
Other	0.30%	(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, 2021	Mar. 31, 2020	Mar. 31, 2019
Deferred tax assets:
Federal net operating loss carryforwards	$ 7,083	$ 2,450
Foreign net operating loss carryforwards	22,195	9,092
State net operating loss carryforwards	2,358	1,054
Research and development credits	787
Property, plant and equipment	5,068	5,499
Capitalized start-up costs	1,597	1,748
Stock compensation	4,838	2,526
Accrued expenses	739	341
Lease liability	8,462	8,705
Total deferred tax assets	53,127	31,415
Deferred tax liabilities:
Right-to-use asset	(13,090)	(13,998)
Other	(9)	(88)
Total deferred tax liabilities	(13,099)	(14,086)
Valuation allowance	(40,028)	$ (17,329)	$ (9,396)
Deferred tax assets operating loss carryforwards
Federal net operating loss carryforwards having indefinite expiration period	33,731
Foreign net operating loss carryforwards having indefinite expiration period	116,815
Federal research and development carryforwards	687
State research and development carryforwards	126
State net operating loss carryforwards, expires between 2039 and 2040	$ 37,311

Income taxes - Valuation allowance for deferred tax assets (Details)	12 Months Ended
	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)
Deferred tax assets, Valuation allowance
Valuation allowance as of beginning of year	$ 17,329,000	$ 9,396,000
Increases recorded to income tax provision	22,624,000	8,047,000
Increases recorded to income tax provision for equity	76,000
Decrease recorded to income tax provision for equity		(114,000)
Valuation allowance as of end of year	40,028,000	17,329,000
Accrued interest or penalties related to uncertain tax positions	0	0
Income tax benefit	$ 0	$ 0
Number of pending tax examination	0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Geographic information (Details) $ in Thousands	12 Months Ended
Geographic information (Details) $ in Thousands	Mar. 31, 2021 USD ($) item	Mar. 31, 2020 USD ($)
Geographic information
Number of operating geographic regions \| item	2
Long-lived assets	$ 7,442	$ 6,860
United States
Geographic information
Long-lived assets	6,866	6,357
United Kingdom
Geographic information
Long-lived assets	$ 576	$ 503

Quarterly financial data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020
Quarterly financial data (unaudited)
Operating expenses	$ 22,184	$ 20,275	$ 19,663	$ 17,833	$ 16,385	$ 16,664	$ 12,242	$ 10,907	$ 79,955	$ 56,198
Net loss attributable to common stockholders	$ (21,499)	$ (21,783)	$ (20,095)	$ (17,493)	$ (15,789)	$ (16,189)	$ (11,139)	$ (9,508)	$ (80,870)	$ (52,625)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.42)	$ (0.44)	$ (0.46)	$ (0.44)	$ (0.41)	$ (0.46)	$ (0.35)	$ (0.30)	$ (1.75)	$ (1.54)

- Definition

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

+ References

+ Details