Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Cash flows from operating activities:
Net loss	$ (108,790,000)	$ (117,501,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	16,731,000	17,199,000
Depreciation and amortization expense	9,152,000	5,869,000
Accretion of discount and amortization of premium on investments, net	(6,912,000)	(8,940,000)
Non-cash lease expense	2,286,000	2,222,000
Realized gain on investments		(34,000)
Impairment of right-of-use assets	0	4,100,000
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,365,000)	1,716,000
Operating lease liabilities	(6,416,000)	4,986,000
Accounts payable and accrued and other liabilities	(4,469,000)	4,223,000
Other long-term liabilities	87,000
Net cash used in operating activities	(99,696,000)	(86,160,000)
Cash flows from investing activities:
Purchases of investments	(406,376,000)	(260,233,000)
Proceeds from sales and maturities of investments	281,230,000	367,395,000
Purchases of property and equipment	(4,409,000)	(28,147,000)
Net cash (used in) provided by investing activities	(129,555,000)	79,015,000
Cash flows from financing activities:
Proceeds from issuance of common stock and pre-funded warrants, net of issuance costs	225,073,000
Proceeds from ESPP purchases	343,000	530,000
Proceeds from stock option exercises	668,000	161,000
Net cash provided by financing activities	226,084,000	691,000
Net decrease in cash and cash equivalents	(3,167,000)	(6,454,000)
Cash, cash equivalents and restricted cash at beginning of year	33,783,000	40,237,000
Cash, cash equivalents and restricted cash at end of year	30,616,000	33,783,000
Reconciliation of cash, cash equivalents and restricted cash to the balance sheets:
Cash and cash equivalents	27,873,000	31,040,000
Restricted cash	2,743,000	2,743,000
Total cash, cash equivalents and restricted cash	30,616,000	33,783,000
Supplemental disclosures of non-cash investing activities:
Acquisitions of property and equipment recorded in accounts payable and accrued and other current liabilities	343,000	268,000
Right-of-use assets obtained in exchange for operating lease liabilities resulting from modified leases	579,000	$ 431,000
Decrease in right-of-use asset and lease liability due to termination	$ 2,229,000