Segment Information - Summary of Segment Performance and Make Decisions About Resource Allocation (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Revenues						$ 251
Operating expenses	$ 22,810		$ 16,190		$ 44,982	30,932
Other income (expense), net	1,556		(1,653)		3,417	(1,125)
Net Income (Loss)	(21,254)	$ (20,311)	(17,843)	$ (13,963)	(41,565)	(31,806)
Personnel-related [Member]
Segment Reporting Information [Line Items]
Operating expenses	9,640		6,991		19,205	13,806
Other [Member]
Segment Reporting Information [Line Items]
Operating expenses	4,484		4,584		9,435	9,175
AB-101 [Member]
Segment Reporting Information [Line Items]
Operating expenses	$ 8,686		4,600		$ 16,342	7,889
Other programs [Member]
Segment Reporting Information [Line Items]
Operating expenses			$ 15			$ 62