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Fair Value of Financial Instruments - Schedule of Calculation of Estimated Fair Value of Success Payment Liabilities (Details) - Success Payment Liabilities | 9 Months Ended | 12 Months Ended
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Sep. 30, 2025 | Dec. 31, 2024
Fair Value of Common Stock | Harvard |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Success payment liability measurement input | 24.27 | 24.8
Fair Value of Common Stock | Broad Institute |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Success payment liability measurement input | 24.27 | 24.8
Expected Volatility | Harvard |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Success payment liability measurement input | 0.74 | 0.78
Expected Volatility | Broad Institute |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Success payment liability measurement input | 0.75 | 0.81
Expected Term (years) | Minimum | Harvard |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Success payment liability, term | 7 days | 10 days
Expected Term (years) | Minimum | Broad Institute |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Success payment liability, term | 7 days | 10 days
Expected Term (years) | Maximum | Harvard |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Success payment liability, term | 3 years 8 months 26 days | 4 years 5 months 26 days
Expected Term (years) | Maximum | Broad Institute |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Success payment liability, term | 4 years 7 months 9 days | 5 years 4 months 9 days

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