Stockholders' equity - Schedule of Pre-funded Warrants (Details) - shares	Sep. 30, 2023	Mar. 31, 2023	Dec. 01, 2022
Stock options, issued and outstanding
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	9,155,387	7,454,828
Restricted stock units
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	2,189,837	1,351,280
Stock options and restricted stock units, future issuance
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	2,064,858	2,209,597
Employee stock purchase plan, available for future grants
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	2,738,208	2,076,603
Pre-IPO warrants to purchase common stock
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	497,344	497,344
Pre-funded warrants
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	7,561,583	9,484,238	4,200,000,000
Total shares of common stock reserved for future issuance
Class of Warrant or Right [Line Items]
Issuance of pre-funded warrants (in shares)	24,207,217	23,073,890