Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net loss	$ (145,435)	$ (71,514)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,875	1,341
Stock-based compensation expense	16,641	7,571
Amortization of operating right-of-use assets	5,021	910
Net amortization of premiums on investments	228	910
Loss on disposal of fixed assets	44	32
Asset impairment charges	213	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	2,852	(16,306)
Other assets	(534)	(3,030)
Operating lease liabilities	2,991	(75)
Accounts payable	(575)	5,601
Accrued compensation	(4)	1,791
Accrued manufacturing expenses	5,830	(5,979)
Accrued expenses	5,477	8,448
Net cash used in operating activities	(105,376)	(70,300)
Cash flows from investing activities:
Purchases of property and equipment	(4,701)	(5,173)
Proceeds from sale of property and equipment	7	0
Purchases of investments	(31,460)	(295,279)
Maturities of investments	136,191	58,000
Sale of investments	10,500	30,062
Net cash provided by (used in) investing activities	110,537	(212,390)
Cash flows from financing activities:
Proceeds from exercise of common stock options	2,363	1,444
Proceeds from issuance of common stock related to at-the-market offering, net of commissions and offering expenses	95,238	7,108
Proceeds from issuance of common stock from follow-on offering, net of issuance costs	107,624	0
Release of restricted stock units	(861)	0
Proceeds from issuance of common stock under the Employee Stock Purchase Plan	550	490
Net cash provided by financing activities	204,914	9,042
Effect of exchange rate changes on cash and cash equivalents	(659)	363
Net increase (decrease) in cash, cash equivalents and restricted cash	209,416	(273,285)
Cash, cash equivalents and restricted cash, beginning of period	69,856	386,200
Cash, cash equivalents and restricted cash, end of period	279,272	112,915
Cash paid for interest	2	7
Supplemental disclosures of non-cash investing and financing activities:
Purchases of property and equipment recorded in accounts payable and accrued expenses	141	271
Stock issued for payment of accounts payable	0	10,000
Proceeds from issuance of common stock through ATM facility not yet received	0	5,011
Deferred offering costs included in accounts payable and accrued expenses	$ 0	$ 154