Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (87,518)	$ (44,899)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,191	831
Stock-based compensation expense	9,993	4,634
Amortization of operating right-of-use assets	3,351	564
Net amortization of premiums on investments	466	481
Loss on disposal of fixed assets	44	0
Asset impairment charges	213	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,022	(6,370)
Other assets	(1,336)	44
Operating lease liabilities	4,414	(307)
Accounts payable	779	4,103
Accrued compensation	(1,395)	1,126
Accrued manufacturing expenses	390	(5,613)
Accrued expenses	1,558	3,521
Net cash used in operating activities	(66,828)	(41,885)
Cash flows from investing activities:
Purchases of property and equipment	(3,858)	(3,454)
Proceeds from sale of property and equipment	7	0
Purchases of investments	(13,869)	(228,531)
Maturities of investments	90,051	21,000
Sales of investments	3,500	17,064
Net cash provided by (used in) investing activities	75,831	(193,921)
Cash flows from financing activities:
Proceeds from exercise of common stock options	606	953
Proceeds from issuance of common stock related to at-the-market offering, net of commissions and offering expenses	52,117	0
Proceeds from issuance of common stock from Follow-on Offering, net of issuance costs	107,624
Proceeds from issuance of common stock under the Employee Stock Purchase Plan	550	490
Net cash provided by financing activities	160,897	1,443
Effect of exchange rate changes on cash and cash equivalents	(712)	30
Net increase (decrease) in cash, cash equivalents and restricted cash	169,188	(234,333)
Cash, cash equivalents and restricted cash, beginning of period	69,856	386,200
Cash, cash equivalents and restricted cash, end of period	239,044	151,867
Supplemental disclosure of cash flow information:
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	529	475
Stock issued for payment of accounts payable	0	10,000
Deferred offering costs included in accounts payable and accrued expenses	$ 1	$ 199