CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash flows from operating activities:
Net loss	$ (499,275)	$ (160,838)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,400	3,480
Non-cash share-based compensation	47,109	8,460
Issuance of common shares as payment for acquisition of IPR&D asset	10,793	0
Issuance of common shares as payment under license and other agreements	71,618	0
Fair value of forward contract and derivative liabilities under license agreement	102,529	0
Change in fair value of forward contract and derivative liabilities	(9,129)	0
Issuance of warrant under license agreement	3,340	0
Other non-cash items, net	(3,129)	(3,682)
Changes in operating assets and liabilities, net of effects of acquisition:
Prepaid expenses and other current and non-current assets	(13,491)	39,283
Accounts payable	(60)	1,336
Accrued expenses and other current and non-current liabilities	15,860	(10,070)
Net cash used in operating activities	(270,435)	(122,031)
Cash flows from investing activities:
Proceeds from maturities of marketable securities	182,364	124,977
Proceeds from sales of marketable securities	0	4,920
Purchases of marketable securities	(243,266)	(53,372)
Purchases of property and equipment	(3,389)	(1,330)
Cash acquired from acquisition of IPR&D asset	391	0
Net cash (used in) provided by investing activities	(63,900)	75,195
Cash flows from financing activities:
Proceeds from issuance of common shares	318,520	0
Payment of issuance costs	(800)	0
Change in restricted cash due to Former Parent	0	5,203
Proceeds from equity incentive plan and employee share purchase plan	4,568	1,126
Other financing activities, net	2,258	0
Net cash provided by financing activities	324,546	6,329
Effects of exchange rates on cash, cash equivalents, and restricted cash	(13)	(147)
Net decrease in cash, cash equivalents, and restricted cash	(9,802)	(40,654)
Cash, cash equivalents, and restricted cash at beginning of period	252,120	242,604
Cash, cash equivalents, and restricted cash at end of period	$ 242,318	$ 201,950