Leases - Additional Information (Detail)						3 Months Ended
	Feb. 28, 2022 USD ($)	Jan. 07, 2021	Dec. 22, 2020 USD ($) ft²	May 01, 2020 USD ($)	Feb. 29, 2020 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset						$ 10,082,000		$ 18,543,000
License term					3 years
Remaining finance lease liabilities						666,000
Operating Lease, Impairment Loss						3,901,000
Security deposit and the last month's license fee	$ 800,000
Moma Therapeutics Inc [Member]
Operating Lease, Right-of-Use Asset
Lessee, operating sub lease, term of contract		18 months
Operating sub lease, cost						500,000
Sublease Income						$ 500,000
Old Premises Cambridge [Member]
Operating Lease, Right-of-Use Asset
Lease expiration date						May 01, 2020
New Premises Boston [Member]
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset				$ 10,600,000
Increase (decrease) in operating lease liability				$ 10,200,000
Percentage of escalation of License fee					3.00%
Total Amount of License fee					$ 12,000,000.0
Merger Laboratory Boston [Member]
Operating Lease, Right-of-Use Asset
Operating lease, initial term						10 years
Operating lease, option to extend additional term						7 years
Operating Lease, Right-of-Use Asset			$ 10,200,000
Increase (decrease) in operating lease liability			$ 10,200,000
Number of Square Feet | ft²			30,000
Operating lease, payments			$ 14,200,000
Merger Laboratory Boston [Member] | Portion of Excess Merger Purchase Price [Member]
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset			1,900,000
Merger Laboratory Boston [Member] | Value Attributable to Below Market Lease [Member]
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset			$ 3,100,000
Maximum [Member]
Operating Lease, Right-of-Use Asset
Total Amount of License fee	400,000
Remaining finance lease liabilities						$ 100,000
Maximum [Member] | Moma Therapeutics Inc [Member]
Operating Lease, Right-of-Use Asset
Operating leases, rent expense, sublease rentals						1,997,520
Minimum [Member]
Operating Lease, Right-of-Use Asset
Total Amount of License fee	$ 100,000
Minimum [Member] | Moma Therapeutics Inc [Member]
Operating Lease, Right-of-Use Asset
Operating leases, rent expense, sublease rentals						$ 1,939,340