Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net Income (Loss)	$ (95,990)	$ (89,056)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, amortization and accretion	(4,086)	(846)
Reduction in the carrying amount of operating lease right-of-use assets	2,224	2,271
Stock-based compensation	11,493	8,887
Issuance of Class A common stock for licensing payment, net of costs	0	3,592
Change in fair value of non-marketable equity securities	47	809
Changes in operating assets and liabilities:
Prepaid expense and other current assets	173	(8,182)
Other assets	(309)	(111)
Accounts payable	(873)	10,606
Accrued and other current liabilities	(2,215)	7,036
Operating lease liabilities	(2,645)	(2,602)
Net cash used in operating activities	(92,181)	(67,596)
Cash flows from investing activities
Purchase of property and equipment	(63)	(62)
Purchase of marketable securities	(224,930)	(148,490)
Proceeds from maturities of marketable securities	176,019	78,000
Proceeds from sale of marketable securities	9,543	0
Net cash used in investing activities	(39,431)	(70,552)
Cash flows from financing activities
Proceeds from exercise of stock options and employee stock purchase plan	1,056	2,083
Proceeds from borrowings, net of costs	24,741	19,816
Proceeds from issuance of Class A common stock in follow-on offering	115,000	86,131
Payment of costs and underwriting discounts and commissions related to follow-on offering	(7,256)	(6,097)
Net cash provided by financing activities	133,541	101,933
Net increase (decrease) in cash and cash equivalents and restricted cash	1,929	(36,215)
Cash, cash equivalents and restricted cash, beginning of year	43,752	79,967
Cash, cash equivalents and restricted cash, end of year	45,681	43,752
Supplemental disclosure of cash flow information
Cash paid for interest	3,352	895
Cash paid for operating leases	3,000	2,734
Issuance of Class A common stock in payment of licensing fees	0	2,000
Cash and cash equivalents [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash, beginning of year	43,459
Cash, cash equivalents and restricted cash, end of year	45,681	43,459
Restricted cash [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash, beginning of year	293
Cash, cash equivalents and restricted cash, end of year	$ 0	$ 293