Segment Reporting - Summary of the Company's segment expenses (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2025	Dec. 31, 2024
Segment Reporting Information [Line Items]
Collaboration arrangement revenue		$ 53,737	$ 0
Personnel-related costs (excluding stock-based compensation)		12,575	16,122
Other G&A expenses		9,709	9,586
Interest (income) expense, net		(1,055)	(2,832)
Other segment items	[1]	(59,838)	(9,978)
Total segment net income (loss)		(29,821)	47,733
ADX-097 [Member]
Segment Reporting Information [Line Items]
Other Research And Development Expense		1,920	5,253
Bempikibart [Member]
Segment Reporting Information [Line Items]
Other Research And Development Expense		6,713	28,726
Discovery and Other [Member]
Segment Reporting Information [Line Items]
Other Research And Development Expense		$ 155	$ 856

[1] (1) Other segment items are included in order to reconcile to total segment net (income) loss. Other segment items include non-cash items such as depreciation and amortization expense, stock-based compensation expense and the change in fair value of contingent value rights. In 2025, other segment items also include the recognition of collaboration arrangement revenue related to the Amendment with Amgen (see Note 16) and the gain recognized related to the ADX-097 Sale (see Note 4). In 2024, other segment items also include gains and losses on the change in fair value of convertible notes and a loss from equity method investment.