Research and Development Agreements - Schedule of Research and Development Revenue from Related Party Relates to Revenue from Research and Development Agreements (Detail)

v3.21.1

Research and Development Agreements - Schedule of Research and Development Revenue from Related Party Relates to Revenue from Research and Development Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue Recognition [Line Items]
Total research and development revenue, related party	$ 3,220	$ 1,800
Millennium Pharmaceuticals Inc
Revenue Recognition [Line Items]
Total research and development revenue, related party	237	333
Millennium Pharmaceuticals Inc | Takeda Development Agreement
Revenue Recognition [Line Items]
Total research and development revenue, related party	215	147
Millennium Pharmaceuticals Inc | Takeda Multi Target Agreement
Revenue Recognition [Line Items]
Total research and development revenue, related party	$ 22	$ 186