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Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Jan. 31, 2021	Dec. 31, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Apr. 01, 2022	Mar. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares available for future issuance (in shares)			17,410,189		17,410,189		4,659,315	13,033,788
Common shares outstanding (in shares)			1,286,372		1,286,372			2,188,860
Intrinsic value of stock options exercised					$ 200
Stock options exercised (in shares)					57,678	0
Weighted average fair value at the grant date (in dollars per share)					$ 4.22
Share based compensation expense			$ 8,856	$ 9,954	$ 24,462	$ 21,443
Research and development expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense			4,137	4,797	11,556	8,602
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized equity-based compensation related to unvested stock options			$ 38,200		$ 38,200
Remaining weighted average service period for recognition					2 years 8 months 15 days
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units outstanding (in shares)			4,528,774		4,528,774			2,670,864
Unrecognized equity-based compensation related to RSUs			$ 20,700		$ 20,700
Remaining weighted average service period for recognition					2 years 9 months 29 days
Restricted stock units, grants in period (in shares)					2,473,469
Roivant Sciences Ltd. (RSL)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expense			0	100	$ 100	400
Roivant Sciences Ltd. (RSL) \| Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized equity-based compensation related to unvested stock options			100		100
Share based compensation expense			$ 100	$ 100	$ 300	$ 500
Restricted stock units, grants in period (in shares)	73,155
Award vesting period	4 years
2019 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares available for future issuance (in shares)		5,500,000	1,286,372		1,286,372
Maximum number of shares issued (in shares)		16,500,000
Percentage of common stock outstanding		4.00%
Common shares outstanding (in shares)			8,355,667		8,355,667
2019 Equity Incentive Plan \| Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units outstanding (in shares)			4,528,774		4,528,774
2018 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares outstanding (in shares)			2,921,615		2,921,615