Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (223,485)	$ (100,077)	$ (89,217)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,577	1,800	1,405
Stock-based compensation expense	23,650	10,729	5,434
Non-cash payments for acquired manufacturing rights	7,995	0	0
Change in fair value of redeemable convertible preferred stock warrant	0	0	179
Loss on disposal of assets	44	97	34
Asset impairment charges	213	0	267
Amortization of operating right-of-use assets	6,619	1,657	0
Net amortization of premiums on investments	(947)	1,406	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	433	(7,369)	(58)
Other assets	(465)	(3,539)	(75)
Operating lease liabilities	1,151	(12,856)	0
Accounts payable	2,896	(12,470)	26,102
Accrued compensation	(2,275)	3,170	(130)
Accrued manufacturing expenses	3,826	(8,572)	7,235
Accrued expenses	7,171	4,631	2,207
Deferred rent and other long-term liabilities	0	0	(11)
Net cash used in operating activities	(170,597)	(121,393)	(46,628)
Cash flows from investing activities:
Purchases of property and equipment	(5,848)	(6,555)	(1,155)
Purchases of investments	(102,745)	(336,341)	0
Maturities of investments	168,691	100,500	0
Sales of investments	14,480	30,062	0
Proceeds from sales of property and equipment	7	26	50
Net cash provided by (used in) investing activities	74,585	(212,308)	(1,105)
Cash flows from financing activities:
Payments of capital lease obligations	0	0	(61)
Proceeds from initial public offering, net of issuance costs	0	0	264,007
Proceeds from issuance of common stock and pre-funded warrants from follow-on offerings, net of issuance costs	759,181	0	0
Proceeds from issuance of common stock under ATM Sales Program, net of issuance costs	97,299	13,896	0
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	0	0	109,879
Proceeds from exercise of common stock options	4,895	3,012	635
Proceeds from issuance of common stock related to early exercised stock options	0	0	36
Proceeds from issuance of common stock under the Employee Stock Purchase Plan	1,033	888	374
Release of restricted stock units	(861)	0	0
Net cash provided by financing activities	861,547	17,796	374,870
Effect of exchange rate changes on cash and cash equivalents	137	(439)	87
Net increase (decrease) in cash, cash equivalents and restricted cash	765,672	(316,344)	327,224
Cash, cash equivalents and restricted cash, beginning of period	69,856	386,200	58,976
Cash, cash equivalents and restricted cash, end of period	835,528	69,856	386,200
Supplemental disclosure of cash flow information:
Cash paid for interest	2	7	7
Supplemental disclosures of non-cash investing and financing activities:
Purchases of property and equipment recorded in accounts payable and accrued expenses	110	766	494
Issuance of common stock for acquired manufacturing rights	7,995	0	0
Conversion of convertible preferred stock into common stock	0	0	270,190
Stock issued for payment of accounts payable	0	10,000	0
Deferred offering costs included in accounts payable and accrued expenses	$ 0	$ 0	$ 134