Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (101,052)	$ (70,760)
Adjustments to reconcile net loss to net cash used in operations:
Net amortization of premiums and discounts on investments in marketable securities	(1,600)	0
Depreciation and amortization	2,352	734
Noncash lease expense	5,994	1,460
Stock-based compensation expense	13,534	7,871
Change in fair value of the Series A redeemable convertible preferred stock tranche liability	0	10,341
Changes in assets and liabilities:
Prepaid expenses and other current assets and other assets	(3,211)	(3,914)
Accounts payable	194	1,825
Accrued compensation	1,110	2,223
Accrued research costs	87	(1,131)
Accrued expenses and other current liabilities and other liabilities	94	257
Operating lease liabilities	(5,482)	(1,758)
Net cash used in operating activities	(87,980)	(52,852)
Cash flows from investing activities:
Purchases of property and equipment	(6,594)	(5,740)
Purchases of investments in marketable securities	(405,519)	0
Proceeds from maturities of marketable securities	170,250	0
Net cash used in investing activities	(241,863)	(5,740)
Cash flows from financing activities:
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	0	165,521
Proceeds from initial public offering, net of issuance costs	0	251,323
Proceeds from issuance of common stock upon exercise of vested stock options	20	28
Proceeds from employee stock purchase plan	656	306
Proceeds from issuance of common stock upon early exercises of stock options	0	289
Repurchase of unvested early exercised shares	(79)	0
Net cash provided by financing activities	597	417,467
Net increase (decrease) in cash, cash equivalents and restricted cash	(329,246)	358,875
Cash, cash equivalents and restricted cash, at beginning of period	378,692	19,817
Cash, cash equivalents and restricted cash, at end of period	49,446	378,692
Reconciliation of cash, cash equivalents and restricted cash to statement of financial position:
Cash and cash equivalents	47,730	376,976
Restricted cash	1,716	1,716
Cash, cash equivalents and restricted cash in statement of financial position	49,446	378,692
Supplemental disclosures of non-cash investing and financing information:
Conversion of redeemable convertible preferred stock to common stock at closing of initial public offering	0	260,532
Property and equipment purchases in accounts payable and accrued expenses	(36)	(75)
Settlement of redeemable convertible preferred stock tranche liability	0	(39,403)
Additions to right-of-use assets from new operating lease liabilities	0	13,034
Lessor funded lease incentives included in property and equipment	11,920	0
Vesting of early exercised stock options	131	144
Repurchase of unvested early exercised shares included in accounts payable	$ (17)	(42)
Proceeds from issuance of common stock upon exercise of stock options included in accounts receivable		$ (14)