Basis of Presentation and Significant Accounting Policies - Narrative (Details) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2024 USD ($) segment $ / shares	Dec. 31, 2023 USD ($) $ / shares	Dec. 31, 2022 USD ($) $ / shares
Class of Stock [Line Items]
Increase in revenue	[1]	$ 61	$ 130	$ 84,683
Reduction in net loss		$ (342,994)	$ (234,632)	$ (183,118)
Reduction in net loss per common share, basic (in dollars per share) | $ / shares		$ (1.31)	$ (0.93)	$ (0.74)
Reduction in net loss per common share, diluted (in dollars per share) | $ / shares		$ (1.31)	$ (0.93)	$ (0.74)
Impairment of long-lived assets		$ 51,297	$ 0	$ 0
Number of operating segments | segment		1
Number of reportable segments | segment		1
Minimum
Class of Stock [Line Items]
Estimated life		3 years
Maximum
Class of Stock [Line Items]
Estimated life		5 years
Adjustment To Revenue Related To Change In Estimate | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | GSK
Class of Stock [Line Items]
Increase in revenue				83,600
Reduction in net loss				$ 83,600
Reduction in net loss per common share, basic (in dollars per share) | $ / shares			$ 0.34	$ 0.34
Reduction in net loss per common share, diluted (in dollars per share) | $ / shares			$ 0.34	$ 0.34

[1] Includes related-party revenue of zero for both the years ended December 31, 2024 and 2023 and $84,653 for the year ended December 31, 2022.