INCOME TAXES - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets (liabilities):
Capitalized research expenses	$ 49,054	$ 25,316
Federal net operating loss carryforward	30,714	22,971
Federal and state R&D credits	16,854	8,913
State net operating loss carryforward	6,956	5,197
Stock-based compensation	4,929	4,120
Accrued expenses	1,661	1,499
Lease liability	1,236	1,411
Orphan Drug Credit	606	691
Property and equipment	107	30
Other	(15)	53
ROU asset	(410)	(586)
Total net deferred tax asset	111,692	69,615
Valuation allowance	(111,692)	(69,615)
Net deferred tax asset (liability)