Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net loss	$ (151,777)	$ (123,524)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,486	1,006
Stock-based compensation expense	28,377	19,832
Amortization of premiums and discounts on marketable securities, net	(8,037)	184
Non-cash operating lease costs	2,154	2,068
Changes in operating assets and liabilities:
Prepaid and other assets	(435)	(3,242)
Accounts payable and accrued liabilities	(588)	12,028
Accrued compensation	(25)	(1,193)
Operating lease liabilities	(2,412)	(1,002)
Deferred revenue	(4,308)	(3,236)
Net cash used in operating activities	(135,565)	(97,079)
Cash flows from investing activities
Maturities of marketable securities	229,450	85,975
Purchases of marketable securities	(407,195)	(266,189)
Purchases of property and equipment	(3,365)	(1,973)
Net cash used in investing activities	(181,110)	(182,187)
Cash flows from financing activities
Proceeds from issuance of common stock in public offerings, net of issuance costs	60,547	101,701
Proceeds from issuance of common stock under employee incentive equity plans	1,426	816
Net cash provided by financing activities	61,973	102,517
Net decrease in cash, cash equivalents and restricted cash	(254,702)	(176,749)
Cash, cash equivalents and restricted cash at beginning of period	340,647	320,699
Cash, cash equivalents and restricted cash at end of period	85,945	143,950
Supplemental schedule of noncash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	$ 1,741	$ 0