SEGMENT INFORMATION - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Segment Reporting Information [Line Items]
Revenues	$ 39,552	$ 57,800
Less:
Research and development	112,670	111,521
General and administrative	34,886	44,727
Impairment of long-lived assets	13,235	5,521
Stock-based compensation	9,079	12,382
Net loss	(122,932)	(97,941)
Reportable Segment
Segment Reporting Information [Line Items]
Revenues	39,552	57,800
Less:
Research and development	57,793	70,289
General and administrative	30,093	37,827
Clinical manufacturing operations	50,711	35,345
Impairment of long-lived assets	13,235	5,521
Stock-based compensation	9,079	12,382
Other segment items	1,573	(5,623)
Net loss	$ (122,932)	$ (97,941)