Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash flows from operating activities
Net loss	$ (62,091)	$ (50,231)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	26	11
Accretion of discount on purchase of debt securities, net	(4,475)	(1,641)
Accretion of loan exit fee and amortization of loan costs	386	153
Reduction in the carrying amount of operating lease right-of-use assets	1,020	1,143
Stock-based compensation	8,997	5,349
Changes in operating assets and liabilities:
Prepaid expense and other current assets	2,328	1,451
Other assets	22	(274)
Accounts payable	(6,454)	1,289
Accrued and other current liabilities	2,889	31
Operating lease liabilities	(1,260)	(1,345)
Net cash used in operating activities	(58,612)	(44,064)
Cash flows from investing activities
Purchase of property and equipment	(89)	0
Purchase of marketable securities	(336,055)	(143,058)
Proceeds from maturities of marketable securities	90,181	59,300
Proceeds from sale of marketable securities	4,000	9,543
Net cash used in investing activities	(241,963)	(74,215)
Cash flows from financing activities
Proceeds from exercise of stock options and employee stock purchase plan	10,350	672
Proceeds from short swing settlement	37	0
Proceeds from issuance of Class A common stock in follow-on offering	287,500	115,000
Payment of costs and underwriting discounts and commissions related to follow-on offering	(17,908)	(7,256)
Net cash provided by financing activities	279,979	108,416
Net decrease in cash and cash equivalents	(20,596)	(9,863)
Cash and cash equivalents, beginning of period	45,681	43,752
Supplemental disclosure of cash flow information
Cash paid for interest expense	3,254	1,636
Cash paid for operating leases	1,528	1,492
Receivable on exercise of stock options.	0	5
Cash and cash equivalents [Member]
Cash flows from financing activities
Cash and cash equivalents, end of period	$ 25,085	$ 33,889