Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net loss	$ (50,197)	$ (16,641)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	255	157
Stock-based compensation expense	7,990	1,136
Amortization of premiums and discounts on marketable securities, net	69	0
Amortization of discounts and loan issuance costs	0	29
Gain on disposal of property and equipment	(16)	0
Noncash interest expense	0	110
Change in fair value of preferred warrant liability	0	75
Changes in operating assets and liabilities:
Prepaid and other assets	(4,394)	(392)
Accounts payable and accrued liabilities	579	1,908
Accrued compensation	151	5
Operating lease right-of-use assets and liabilities, net	299	2
Deferred revenue	(2,552)	(1,320)
Net cash used in operating activities	(47,816)	(14,931)
Cash flows from investing activities
Maturities of marketable securities	3,580	0
Purchases of property and equipment	(1,233)	(10)
Net cash provided by (used in) investing activities	2,347	(10)
Cash flows from financing activities
Proceeds from issuance of common stock in initial public offering, gross	0	298,080
Payment of issuance costs related to initial public offering	0	(22,680)
Proceeds from exercise of stock options, net of repurchases	122	16
Proceeds from issuance of common stock under employee stock purchase plan	318	0
Payments on long-term debt	0	(4,683)
Proceeds from issuance of Series C convertible preferred stock, net of issuance costs	0	2,200
Payment of deferred financing costs	(10)	0
Net cash provided by financing activities	430	272,933
Net (decrease) increase in cash, cash equivalents and restricted cash	(45,039)	257,992
Cash, cash equivalents and restricted cash at beginning of period	321,713	94,578
Cash, cash equivalents and restricted cash at end of period	276,674	352,570
Supplemental disclosure of cash flow information:
Cash paid for interest	0	571
Supplemental schedule of noncash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	0	676
Costs incurred, but not paid, in connection with initial public offering costs included in accounts payable and accrued liabilities	0	1,346
Costs incurred, but not paid, in connection with deferred financing costs included in accounts payable and accrued liabilities	90	0
Costs incurred, but not paid, in connection with purchases of property and equipment included in accounts payable and accrued liabilities	94	287
Conversion of convertible preferred stock into common stock upon completion of initial public offering	0	136,920
Reclassification of warrant liability to equity due to adjustment from preferred stock warrant to common stock warrant upon completion of initial public offering	$ 0	$ 120