Research Collaboration and Exclusive License Agreement - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) Target	Mar. 31, 2021 USD ($)
Research And Development Arrangement Contract To Perform For Others [Line Items]
Accounts receivable outstanding	$ 0
Merck Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Collaborative arrangement effective date	Dec. 15, 2020
Number of collaboration targets | Target	2
Non-refundable and non-creditable upfront fee	$ 8,000
Payable upon selection of second collaboration target	8,000
Milestone payments	285,000
Revenue recognized	1,600	$ 400
Deferred revenue	4,600
Merck Agreement | Maximum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone payments per collaboration target	142,500
Milestone payments upon successful completion of certain commercial milestones	$ 350,000