Impairment of Long-Lived Assets	12 Months Ended
Dec. 31, 2025
Impairment or Disposal of Tangible Assets Disclosure [Abstract]
Impairment of Long-Lived Assets	11. Impairment of long-lived assets As a result of changes in business plans and the Company's intention to pursue potential subleases for the Bothell facility and the Seattle facility, due in part to the Company’s decision to suspend further build-out of its internal manufacturing capabilities at the Bothell facility in the-near term due to increased availability of manufacturing capacity at third-party contract development and manufacturing organizations for cell and gene therapy products, as well as progress in understanding its near-term manufacturing needs, and other factors, the Company determined that during the second quarter of 2025 a triggering event occurred and performed an impairment analysis. For the Bothell facility, the Company determined that the combined operating lease ROU asset and construction in progress were not fully recoverable as the carrying value exceeded the estimated fair value and recorded a non-cash impairment loss of $34.2 million for this asset group. For the Seattle facility, the Company determined that the combined operating lease ROU asset and leasehold improvements were not fully recoverable as the carrying value exceeded the estimated fair value and recorded a non-cash impairment loss of $3.8 million for this asset group. In addition, in connection with the Bothell facility and the Seattle facility, the Company recognized non-cash impairment losses related to laboratory equipment of $3.8 million and $2.0 million, respectively. The Company also recognized an additional $0.8 million non-cash impairment loss for other long-lived assets. The losses were recorded in operating expenses in the statement of operations in the second quarter of 2025. During the fourth quarters of 2024 and 2023, the Company recognized $1.9 million and $7.0 million, respectively, for the impairment of certain laboratory equipment and leasehold improvements as a result of the portfolio prioritizations in the fourth quarters of 2024 and 2023.

Impairment of Long-Lived Assets

12 Months Ended

Dec. 31, 2025

Impairment or Disposal of Tangible Assets Disclosure [Abstract]

11. Impairment of long-lived assets

As a result of changes in business plans and the Company's intention to pursue potential subleases for the Bothell facility and the Seattle facility, due in part to the Company’s decision to suspend further build-out of its internal manufacturing capabilities at the Bothell facility in the-near term due to increased availability of manufacturing capacity at third-party contract development and manufacturing organizations for cell and gene therapy products, as well as progress in understanding its near-term manufacturing needs, and other factors, the Company determined that during the second quarter of 2025 a triggering event occurred and performed an impairment analysis. For the Bothell facility, the Company determined that the combined operating lease ROU asset and construction in progress were not fully recoverable as the carrying value exceeded the estimated fair value and recorded a non-cash impairment loss of $34.2 million for this asset group. For the Seattle facility, the Company determined that the combined operating lease ROU asset and leasehold improvements were not fully recoverable as the carrying value exceeded the estimated fair value and recorded a non-cash impairment loss of $3.8 million for this asset group. In addition, in connection with the Bothell facility and the Seattle facility, the Company recognized non-cash impairment losses related to laboratory equipment of $3.8 million and $2.0 million, respectively. The Company also recognized an additional $0.8 million non-cash impairment loss for other long-lived assets. The losses were recorded in operating expenses in the statement of operations in the second quarter of 2025. During the fourth quarters of 2024 and 2023, the Company recognized $1.9 million and $7.0 million, respectively, for the impairment of certain laboratory equipment and leasehold improvements as a result of the portfolio prioritizations in the fourth quarters of 2024 and 2023.