Subsequent Events - Additional Information (Detail) $ / shares in Units, $ in Millions			1 Months Ended			12 Months Ended
	Feb. 18, 2022 ft² USD_per_sqft	Feb. 12, 2022 USD ($)	Feb. 02, 2022 USD ($) $ / shares shares	Jan. 01, 2022 USD_per_sqft	Oct. 31, 2021 USD ($)	Jan. 31, 2022 ft² USD_per_sqft	Dec. 31, 2021 $ / shares shares	Dec. 31, 2022	Dec. 31, 2020 $ / shares shares
Subsequent Event [Line Items]
Operating lease, existence of option to extend							true
Common stock, par value | $ / shares							$ 0.0001		$ 0.0001
Common stock, shares issued | shares							74,485,883		66,234,056
Sparing Vision [Member]
Subsequent Event [Line Items]
Development and commercial milestone payment to be received					$ 200.0
Lease [Member]
Subsequent Event [Line Items]
Operating lease, description							In January 2022, the Company entered into a Lease Agreement (the “Lease”) with the Massachusetts Institute of Technology (the “Landlord”) for office and laboratory space located at 730 Main Street, Cambridge, Massachusetts (the “Premises”). Under the terms of the Lease, the Company will lease approximately 38,000 square feet at the Premises, which will supplement the Company’s current leased premises in Cambridge, Massachusetts. The Lease, including the obligation to pay rent, is expected to commence on October 22, 2022 (the “Commencement Date”).
Operating lease, options to extend							The Company has the option to extend the Lease for one five-year term
Subsequent Event [Member] | Sparing Vision [Member]
Subsequent Event [Line Items]
Development and commercial milestone payment to be received		$ 184.0
Subsequent Event [Member] | Lease [Member]
Subsequent Event [Line Items]
Area Of Space Leased | ft²	140,000					38,000
Term of lease								10 years
Base rent per square foot for first year | USD_per_sqft	73.50			130.00
Base rent per square foot for last year | USD_per_sqft						169.62
Subsequent Event [Member] | Rewrite Holders
Subsequent Event [Line Items]
Upfront Consideration Payable In Cash			$ 45.0
milestone payments			$ 155.0
Common stock, par value | $ / shares			$ 0.0001
Common stock, shares issued | shares			25.0
Cash			$ 130.0