Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (60,462)	$ (38,986)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	712	582
Stock-based compensation expense	9,648	4,099
Amortization of operating right-of-use assets	1,630	1,787
Net amortization of premiums on investments	(5,990)	321
Loss on disposal of fixed assets	0	44
Asset impairment charges	0	57
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(4,702)	2,791
Other assets	615	(1,577)
Operating lease liabilities	(1,356)	5,619
Accounts payable	1,789	(1,933)
Accrued compensation	699	(2,185)
Accrued manufacturing expenses	6,689	2,416
Accrued expenses	3,038	(737)
Net cash used in operating activities	(47,690)	(27,702)
Cash flows from investing activities:
Purchases of property and equipment	(5,609)	(2,920)
Purchases of investments	(483,779)	(6,972)
Maturities of investments	40,160	59,551
Sale of investments	1,127	0
Proceeds from sale of property and equipment	0	7
Net cash (used in) provided by investing activities	(448,101)	49,666
Cash flows from financing activities:
Proceeds from exercise of common stock options	502	282
Proceeds from issuance of common stock related to at-the-market offering, net of issuance costs	41,787	3,115
Proceeds from issuance of common stock from follow-on offering, net of issuance costs	0	107,622
Release of restricted stock units	(727)	0
Net cash provided by financing activities	41,562	111,019
Effect of exchange rate changes on cash and cash equivalents	23	(227)
Net (decrease) increase in cash, cash equivalents and restricted cash	(454,206)	132,756
Cash, cash equivalents and restricted cash, beginning of period	835,528	69,856
Cash, cash equivalents and restricted cash, end of period	381,322	202,612
Supplemental disclosures of non-cash investing and financing activities:
Purchases of property and equipment recorded in accounts payable and accrued expenses	57	664
Deferred offering costs included in accounts payable and accrued expenses	$ 0	$ 23