License and Collaboration Agreements - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended
	Dec. 31, 2020	Jan. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
License And Collaboration Agreements [Line Items]
Net upfront revenue			$ 18,943,000
Type of revenue [Extensible List]			us-gaap:LicenseMember	us-gaap:LicenseMember
Research and development costs			$ 12,415,000	$ 4,173,000
Collaboration and License Agreements
License And Collaboration Agreements [Line Items]
Research and development costs			3,000,000	$ 240,000
Pearl—Zai Lab License Agreement
License And Collaboration Agreements [Line Items]
Nonrefundable license fee		$ 20,000,000
Net upfront revenue		$ 18,900,000
Type of revenue [Extensible List]		us-gaap:LicenseMember
Pearl—Zai Lab License Agreement | Maximum
License And Collaboration Agreements [Line Items]
Aggregate amount of milestone payment	$ 211,000,000
Pearl - Taiho | Collaboration and License Agreements
License And Collaboration Agreements [Line Items]
Research and development costs		$ 3,000,000	$ 3,000,000