Segment Reporting - Summary of Financial Information of Reportable Segment (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information [Line Items]
Total R&D program expense		$ 42,123	$ 41,459
Equity-based compensation		7,616	9,374
Loss from operations		(53,697)	(54,996)
Interest income		4,098	6,580
Other income (expense), net		(62)	(85)
Net loss		(49,661)	(48,501)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total R&D program expense		28,325	27,661
Equity-based compensation		7,616	9,374
R&D personnel and operations		9,839	9,831
General and administrative personnel		3,795	3,489
License agreement obligations		0	38
Other segment expenses	[1]	4,122	4,603
Loss from operations		(53,697)	(54,996)
Interest income		4,098	6,580
Other income (expense), net		(62)	(85)
Net loss		(49,661)	(48,501)
Operating Segments [Member] | CLN-049 [Member]
Segment Reporting Information [Line Items]
Total R&D program expense		5,059	3,895
Operating Segments [Member] | CLN-617 [Member]
Segment Reporting Information [Line Items]
Total R&D program expense		685	1,793
Operating Segments [Member] | CLN-619 [Member]
Segment Reporting Information [Line Items]
Total R&D program expense		2,471	6,118
Operating Segments [Member] | CLN-978 [Member]
Segment Reporting Information [Line Items]
Total R&D program expense		9,665	4,673
Operating Segments [Member] | Early-stage programs [Member
Segment Reporting Information [Line Items]
Total R&D program expense		709	1,022
Operating Segments [Member] | Velinotamig [Member]
Segment Reporting Information [Line Items]
Total R&D program expense		2,803	0
Operating Segments [Member] | Zipalertinib [Member]
Segment Reporting Information [Line Items]
Total R&D program expense		$ 6,933	$ 10,160

[1] Other segment expenses for the three months ended March 31, 2026 and 2025 include legal fees relating to patent and corporate matters; professional fees for accounting, auditing, tax, and administrative consulting services; insurance costs; marketing expenses; depreciation; and other operating costs.