Commitments and Contingencies - Additional Information (Detail) $ in Thousands									1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 09, 2023	Aug. 09, 2021	Oct. 27, 2020 USD ($)	Aug. 04, 2020	May 28, 2020 USD ($) ft²	Dec. 11, 2019 USD ($)	Aug. 08, 2019	Nov. 05, 2018	Jan. 31, 2023	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Oct. 31, 2023 USD ($)	Nov. 30, 2016 USD ($)
Other Commitments [Line Items]
Operating lease right-of-use assets										$ 2,898		$ 2,898		$ 2,858
Operating lease liabilities										$ 4,682		$ 4,682		$ 4,797
Weighted average remaining lease term in years										5 years 10 months 24 days		5 years 10 months 24 days		6 years 9 months 18 days
Weighted average discount rate										11.00%		11.00%		11.00%
Lease expenses										$ 100	$ 100	$ 200	$ 200
Pennsylvania [Member] | Office [Member]
Other Commitments [Line Items]
Operating lease term							3 years 6 months
Lease extension period	3 years						3 years
Lease term commencement date	Sep. 01, 2023						Feb. 15, 2020
Operating lease right-of-use assets										500		500
Operating lease liabilities										$ 500		$ 500
Pennsylvania [Member] | Additional Office [Member] | Subsequent Event [Member]
Other Commitments [Line Items]
Operating lease right-of-use assets															$ 300
Operating lease liabilities															$ 300
Pennsylvania [Member] | Office and Lab [Member]
Other Commitments [Line Items]
Lease extension period								2 years
Lease term commencement date								Jan. 01, 2019
Lease term expiration date		Dec. 31, 2022		Dec. 31, 2021				Dec. 31, 2020	Dec. 31, 2023
Massachusetts [Member] | Office [Member]
Other Commitments [Line Items]
Area of office space | ft²					17,705
Lease term expiration date					Oct. 30, 2029
Massachusetts [Member] | Office [Member] | Letter of Credit
Other Commitments [Line Items]
Letter of credit					$ 1,300
Massachusetts [Member] | Office Sublease [Member]
Other Commitments [Line Items]
Lease term commencement date			Dec. 04, 2020
Lease term expiration date			Oct. 30, 2029
Massachusetts [Member] | Office Sublease [Member] | First Sublease Year [Member]
Other Commitments [Line Items]
Annual base rent			$ 800
Massachusetts [Member] | Office Sublease [Member] | First Sublease Year [Member] | Letter of Credit
Other Commitments [Line Items]
Lease security deposits letters of credit			800
Massachusetts [Member] | Office Sublease [Member] | Final Sublease Year [Member]
Other Commitments [Line Items]
Annual base rent			1,000
Massachusetts [Member] | Office Sublease [Member] | Sixth Sublease Year | Letter of Credit
Other Commitments [Line Items]
Lease security deposits letters of credit			$ 400
WFUHS [Member]
Other Commitments [Line Items]
License agreement consideration deduction percentage																60.00%
WFUHS [Member] | Maximum [Member]
Other Commitments [Line Items]
Milestone payments																$ 2,600
IU [Member]
Other Commitments [Line Items]
License agreement consideration deduction percentage																20.00%
IU [Member] | Maximum [Member]
Other Commitments [Line Items]
Milestone payments																$ 2,600
Annual royalty pay obligation																$ 100
WFUHS and IU [Member] | Research and Development Expenses [Member]
Other Commitments [Line Items]
Milestone expenses														$ 300
WFUHS and IU [Member] | Maximum [Member]
Other Commitments [Line Items]
Payment for license agreements						$ 100