Collaboration and Licensing Agreements - Recognized Revenue (Details) $ in Thousands, ¥ in Millions	3 Months Ended			12 Months Ended			98 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2025 JPY (¥)	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2025 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				$ 407,320	$ 333,615	$ 124,456
2017 KKC Agreement | Kyowa Kirin
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues							$ 35,000
Licensing revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				5,088	78	35,809
Licensing revenue | METiS Therapeutics Inc
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				0	0	750
Licensing revenue | 2017 KKC Agreement | Kyowa Kirin
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				0	0	30,000
Licensing revenue | Fosun Agreement | Fosun Pharma
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues			$ 5,000	5,000	0	5,000
Licensing revenue | Knight Agreement | Knight
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				88	78	59
Product supply revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				15,879	11,649	6,121
Product supply revenue | 2017 KKC Agreement | Kyowa Kirin
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				15,625	11,649	6,092
Product supply revenue | Knight Agreement | Knight
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				254	0	29
Non-cash royalty revenue related to the sale of future royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues				8,545	2,692	0
Non-cash royalty revenue related to the sale of future royalties | Kyowa Kirin
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 3,400			3,400
Non-cash royalty revenue related to the sale of future royalties | 2017 KKC Agreement | Kyowa Kirin
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues		¥ 500.0		$ 8,545	$ 2,692	$ 0