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Segment Reporting - Segment Profit And Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting
Research and development	$ 27,786	$ 15,726
General and administrative	9,209	8,424
Stock-based compensation expense	3,839	2,754
Other income, net	3,286	4,222
Net loss	(33,709)	(19,928)
Single reportable segment
Segment Reporting
Stock-based compensation expense	3,839	2,754
Consulting and professional services expenses	3,975	3,490
Other segment expenses	1,742	1,421
Other income, net	(3,286)	(4,222)
Net loss	33,709	19,928
Single reportable segment | Navenibart
Segment Reporting
Research and development	11,829	7,136
Single reportable segment | STAR-0310
Segment Reporting
Research and development	7,436	2,975
Single reportable segment | Employee expenses
Segment Reporting
Research and development	4,650	3,437
General and administrative	$ 3,524	2,862
Single reportable segment | Program support
Segment Reporting
General and administrative		$ 75

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