License and Other Agreements - Additional Information (Detail) - USD ($)	1 Months Ended				3 Months Ended		6 Months Ended
	Jan. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jan. 31, 2020	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment received				$ 8,000,000.0
Milestone payments received	$ 2,000,000.0
Hong Kong University of Science and Technology [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Collaborative agreement, funding received			$ 750,000
Funding of project cost, description			The ITC funded approximately 50% of the total estimated project cost and we contributed the remaining 50%. The research grant agreement between Pangu BioPharma, HKUST and the Government of the Hong Kong Special Administration Region became effective April 1, 2020
Expenses					$ 45,000	$ 100,000	$ 100,000	$ 300,000
Development Regulatory And Sales Milestones [Member] | Kyorin Pharmaceutical Co Ltd [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Remaining receivable based on achievement of research milestones				165,000,000.0
Development Regulatory And Sales Milestones [Member] | Kyorin Pharmaceutical Co Ltd [Member] | Collaboration Revenue [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment received					$ 0	$ 0	$ 0	$ 0
Stand-alone selling price of license		$ 100,000		$ 7,900,000