Leases - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended
	May 31, 2020	Mar. 31, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Lessee Lease Description [Line Items]
Lessee, operating lease, expiration period			We currently have three operating leases for administrative and research and development office and lab space in San Diego, California and Boston, Massachusetts that expire between July 2024 and November 2025.
Lease option to extend, description			Two of our leases include renewal options for an additional five years, which were not included in the determination of the right-of-use, or ROU, asset or lease liability as the renewal was not reasonably certain at the inception of the lease
Weighted-average discount rate			5.50%		5.50%
Weighted-average remaining lease term			3 years		3 years 3 months 18 days
Total cash paid for amounts included in the measurement of lease liabilities			$ 600,000	$ 500,000
ROU assets obtained in exchange for operating lease liabilities			0	0
ASC 842
Lessee Lease Description [Line Items]
Total operating lease rent expense			500,000	$ 500,000
San Diego Corporate Headquarters Lease
Lessee Lease Description [Line Items]
Operating lease, existence of option to extend	true
Lease agreement additional extended lease term	5 years
Tenant improvement allowance			1,000,000.0
San Diego Lease for Lab and Office Space
Lessee Lease Description [Line Items]
Tenant improvement allowance			100,000
Office Lease in Boston | Letter of Credit
Lessee Lease Description [Line Items]
Letter of Credit			$ 200,000
Boston Lease
Lessee Lease Description [Line Items]
Operating lease, existence of option to extend		true
Lease agreement additional extended lease term		5 years