Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net loss	$ (518,494)	$ (62,015)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	22,086	15,791
Depreciation and amortization	464	167
Non-cash lease expense	(109)	(38)
Change in fair value of warrant liability	(209)	(260)
Amortization of premium on marketable securities	(7,346)	(8,798)
Realized loss on marketable securities	17	183
Net loss on disposal of property and equipment	171	19
Acquired in-process research and development	425,070	0
Change in operating assets and liabilities:
Accounts receivable	(112)	0
Prepaid expenses and other current assets	(7,336)	843
Interest receivable on marketable securities	(437)	(548)
Other non-current assets	104	(587)
Accounts payable	4,378	234
Contract liabilities	(1,868)	0
Accrued expenses	(490)	2,039
Net cash used in operating activities	(84,111)	(52,970)
Cash flow from investing activities:
Cash acquired from AnHeart acquisition	19,863	0
Transaction costs related to AnHeart acquisition	(7,343)	0
Purchases of marketable securities	(307,603)	(554,635)
Proceeds from sale of marketable securities	366,189	530,449
Purchases of property and equipment	(175)	(56)
Net cash provided by (used in) investing activities	70,931	(24,242)
Cash flow from financing activities:
Proceeds from borrowings	7,035	0
Payments on borrowings	(9,530)	0
Proceeds from issuance of Common Stock under ESPP	108	133
Proceeds from exercises of options	3,618	375
Net cash provided by financing activities	1,231	508
Effect of foreign exchange rate changes on cash and cash equivalents	(664)	0
Net decrease in cash and cash equivalents	(12,613)	(76,704)
Cash and cash equivalents, beginning of the period	42,649	101,099
Cash and cash equivalents, end of the period	30,036	24,395
Non-cash investing activities:
Issuance of Common Stock related to the AnHeart acquisition	89,297	0
Issuance of convertible preferred stock related to the AnHeart acquisition	274,938	0
Issuance of warrants related to the AnHeart acquisition	764	0
Issuance of replacement awards related to the AnHeart acquisition	24,818	0
Non-cash operating activities:
Right-of-use asset recognized	213	1,216
Operating lease liability recognized	$ 213	$ 1,216