Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss and comprehensive loss	$ (124,485)	$ (146,696)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	32,399	30,324
Depreciation	1,012	1,062
Non-cash interest expense	568	1,818
Amortization of operating lease right-of-use assets	1,475	1,250
Other	0	9
Changes in operating assets and liabilities:
Accounts receivable	(17,725)	(15,340)
Inventories	(21,794)	(4,126)
Prepaid expenses and other current assets	(15,549)	(7,259)
Amount due from related party	(2,417)	(550)
Other assets	9,738	(3,641)
Accounts payable	(33)	(5,679)
Accrued expenses and other current liabilities	18,739	13,811
Deferred revenue	(9,025)	3,480
Amounts due to Pfizer	(6,795)	35,773
Cost share advance from Pfizer	(34,386)	(68,654)
Operating lease liabilities	(1,618)	(1,326)
Amounts due to related parties	108	(152)
Other liabilities	6	(2,576)
Net cash used in operating activities	(169,782)	(168,472)
Cash flows from investing activities:
Purchases of marketable securities	(24,864)	(118,837)
Maturities of marketable securities	28,500	59,252
Purchases of property and equipment	(614)	(723)
Net cash provided by (used) in investing activities	3,022	(60,308)
Cash flows from financing activities:
Proceeds from stock option exercises	0	1,280
Capital contribution- other	6,714	17,862
Net cash provided by financing activities	6,714	19,142
Net change in cash, cash equivalents and restricted cash	(160,046)	(209,638)
Cash, cash equivalents and restricted cash, beginning of period	416,804	677,480
Cash, cash equivalents and restricted cash, end of period	256,758	467,842
Supplemental Disclosures of Non-Cash Financing and Investing Information:
Change in fair value of share-based awards recorded to additional paid-in capital	0	1,738
Reclassification of share-based compensation liabilities to additional paid-in capital upon settlement of awards	0	20,650
Right-of-use asset obtained in exchange for operating lease obligation	$ 612	$ 0