Condensed Statements of Cash Flows (Unaudited) $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Cash flows from operating activities:
Net loss	$ (51,830)	$ (4,837)
Adjustments to reconcile net loss to net cash used in operations:
Depreciation and amortization	404	45
Noncash lease expense	356
Interest expense related to convertible notes		40
Stock-based compensation expense	5,425	37
Change in fair value of the Series A redeemable convertible preferred stock tranche liability	10,341	(380)
Changes in assets and liabilities:
Prepaid expenses and other current assets and other assets	(5,002)	(257)
Accounts payable	1,115	393
Accrued compensation	1,193	170
Accrued research costs	(34)	977
Accrued expenses and other current liabilities and other liabilities	716	362
Operating lease liabilities	57
Net cash used in operating activities	(37,259)	(3,450)
Cash flows from investing activities:
Purchases of property and equipment	(4,759)	(933)
Net cash used in investing activities	(4,759)	(933)
Cash flows from financing activities:
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	165,521	9,887
Proceeds from issuance of initial public offering, net of issuance costs	251,323
Proceeds from issuance of convertible note to related party		5,000
Proceeds from issuance of common stock upon exercise of stock options	21
Proceeds from issuance of common stock shares upon early exercises of stock options	289	69
Net cash provided by financing activities	417,154	14,956
Net increase in cash, cash equivalents and restricted cash	375,136	10,573
Cash, cash equivalents and restricted cash, at beginning of period	19,817	6
Cash, cash equivalents and restricted cash, at end of period	394,953	10,579
Reconciliation of cash, cash equivalents and restricted cash to statement of financial position:
Cash and cash equivalents	394,804	10,544
Restricted cash	149	35
Cash, cash equivalents and restricted cash, at end of period	394,953	10,579
Supplemental disclosures of non-cash investing and financing information:
Issuance of redeemable convertible preferred stock upon conversion of outstanding related party convertible note and accrued interest		5,020
Issuance costs of redeemable convertible preferred stock in accrued expenses and accounts payable		66
Related party convertible note and accrued interest cancellation		(2,225)
Purchases of property and equipment included in accounts payable	53	131
Settlement of redeemable convertible preferred stock tranche liability	(39,403)
Conversion of redeemable convertible preferred stock to common stock at closing of initial public offering	260,532
Additions to right-of-use assets from new operating lease liabilities	9,433
Vesting of early exercised stock options	$ 69	$ 5