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Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | ---
Jan. 31, 2010 cvr | Mar. 31, 2025 USD ($) | Mar. 31, 2024 USD ($) | Jun. 30, 2024 | Dec. 31, 2024 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Derivative Asset Statement Of Financial Position Extensible Enumeration Not Disclosed Flag |  | Derivative assets(2) |  | Derivative assets(2) |
Number of CVR series | cvr | 4 |  |  |  |
Transferred over Time | Phase 3 clinical trial |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Gross contract asset |  | $ 10,000 |  |  |
Minimum | Agenus Partnered Program | Discount Rate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Discount rate (as a percent) |  | 0.15 |  |  | 0.15
Maximum | Agenus Partnered Program | Discount Rate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Discount rate (as a percent) |  | 0.28 |  |  | 0.28
Maximum | Transferred over Time | Development, regulatory, & commercial milestones and tiered royalties |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  | $ 375,000 |  |  |
Metabasis |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Number of CVRs issued per acquiree share | cvr | 4 |  |  |  |
Number of CVRs issued from each CVR series | cvr | 1 |  |  |  |
Frequency of cash payments to CVR holders | 6 months |  |  |  |
(Decrease) increase of mark-to-market adjustment of CVR liability |  | 1,800 | $ (100) |  |
Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investment in Viking common stock |  | 24,150 |  |  | $ 40,240
Derivative asset |  | 18,029 |  |  | 10,583
Total assets |  | 178,941 |  |  | 194,441
Total liabilities |  | 5,510 |  |  | 3,681
Recurring | Short-term investments, excluding Viking |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments, fair value |  | 136,762 |  |  | 143,618
Recurring | Contingent liabilities | CyDex |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Contingent liabilities |  | 388 |  |  | 383
Recurring | Contingent liabilities | Metabasis |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Contingent liabilities |  | 5,122 |  |  | 3,298
Recurring | Level 1 |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investment in Viking common stock |  | 24,150 |  |  | 40,240
Derivative asset |  | 0 |  |  | 0
Total assets |  | 96,220 |  |  | 122,047
Total liabilities |  | 0 |  |  | 0
Recurring | Level 1 | Short-term investments, excluding Viking |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments, fair value |  | 72,070 |  |  | 81,807
Recurring | Level 1 | Contingent liabilities | CyDex |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Contingent liabilities |  | 0 |  |  | 0
Recurring | Level 1 | Contingent liabilities | Metabasis |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Contingent liabilities |  | 0 |  |  | 0
Recurring | Level 2 |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investment in Viking common stock |  | 0 |  |  | 0
Derivative asset |  | 0 |  |  | 0
Total assets |  | 64,692 |  |  | 61,811
Total liabilities |  | 5,122 |  |  | 3,298
Recurring | Level 2 | Short-term investments, excluding Viking |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments, fair value |  | 64,692 |  |  | 61,811
Recurring | Level 2 | Contingent liabilities | CyDex |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Contingent liabilities |  | 0 |  |  | 0
Recurring | Level 2 | Contingent liabilities | Metabasis |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Contingent liabilities |  | 5,122 |  |  | 3,298
Recurring | Level 3 |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investment in Viking common stock |  | 0 |  |  | 0
Derivative asset |  | 18,029 |  |  | 10,583
Total assets |  | 18,029 |  |  | 10,583
Total liabilities |  | 388 |  |  | 383
Recurring | Level 3 | Short-term investments, excluding Viking |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments, fair value |  | 0 |  |  | 0
Recurring | Level 3 | Contingent liabilities | CyDex |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Contingent liabilities |  | 388 |  |  | 383
Recurring | Level 3 | Contingent liabilities | Metabasis |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Contingent liabilities |  | $ 0 |  |  | $ 0

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