Subsequent Events	12 Months Ended
Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events Office Space Lease On January 22, 2024, the Company entered into a lease agreement (the “Lease”) for approximately 30,567 rentable square feet of office space in a multi-tenant building located in Cambridge, Massachusetts (the “Premises”). The Company will relocate its corporate headquarters to the Premises upon the expiration on August 31, 2024 of (i) the lease of 63,017 square feet of office space for the Company’s current headquarters at 215 First Street, Cambridge, Massachusetts, the first multi-tenant building; and (ii) the lease of 40,419 square feet of additional office space at 245 First Street, Cambridge, Massachusetts, the second multi-tenant building, each in accordance with its terms. The term of the Lease will commence on the later of (1) September 1, 2024, or (2) the date on which improvements to the premises are, or are deemed to be, substantially completed (the “Commencement Date”). The Company’s obligation for the payment of rent for the premises begins six months after the Commencement Date (the “Rent Commencement Date”). The Lease has an initial term of approximately sixty-six months, measured from the Commencement Date. The monthly base rent due under the Lease initially shall be $224,158 per month for the first year following the Rent Commencement Date and is scheduled to increase by approximately 3% per annum for each subsequent year. The Company has the option to extend the Lease one time for an additional five-year period, subject to the terms therein. In connection with its entry into the Lease and as a security deposit, the Company has provided the landlord a letter of credit in the amount of approximately $1.4 million, which the Company and the landlord have agreed may be reduced to approximately $1.2 million following the third anniversary of the Rent Commencement Date, provided that no event of default by the Company has occurred. The landlord has the right to terminate the Lease upon customary events of default. Option Exchange Program On January 23, 2024, the Company initiated a tender offer related to a one-time stock option exchange program pursuant to which eligible non-executive officer employees are being given the opportunity to exchange certain outstanding stock options to purchase shares of the Company’s common stock for replacement options to purchase a lesser number of shares of common stock (the “Option Exchange”). Stock options eligible for exchange have an exercise price per share of $35.00 or greater, in addition to certain other requirements, and will be exchanged for replacement options with an exercise price per share equal to the fair market value of the Company’s common stock on the date of grant of the replacement options, which is currently expected to be February 21, 2024. Approximately 3.5 million outstanding stock options are eligible to be exchanged. All the replacement options will be granted in exchange for tendered options at ratios ranging from 1.50:1 to 5:00:1, depending on the current exercise price of the tendered option. Holders of eligible options may elect to tender their eligible options through the expiration of the offer period, which is currently expected to be February 20, 2024. The Company does not expect to incur significant additional stock-based compensation expense as a result of the Option Exchange. The consummation of the Option Exchange was subject to approval by the Company’s stockholders, which approval was received at the special meeting of stockholders held on January 31, 2024.

Subsequent Events

12 Months Ended

Dec. 31, 2023

14. Subsequent Events

Office Space Lease

On January 22, 2024, the Company entered into a lease agreement (the “Lease”) for approximately 30,567 rentable square feet of office space in a multi-tenant building located in Cambridge, Massachusetts (the “Premises”). The Company will relocate its corporate headquarters to the Premises upon the expiration on August 31, 2024 of (i) the lease of 63,017 square feet of office space for the Company’s current headquarters at 215 First Street, Cambridge, Massachusetts, the first multi-tenant building; and (ii) the lease of 40,419 square feet of additional office space at 245 First Street, Cambridge, Massachusetts, the second multi-tenant building, each in accordance with its terms. The term of the Lease will commence on the later of (1) September 1, 2024, or (2) the date on which improvements to the premises are, or are deemed to be, substantially completed (the “Commencement Date”). The Company’s obligation for the payment of rent for the premises begins six months after the Commencement Date (the “Rent Commencement Date”). The Lease has an initial term of approximately sixty-six months, measured from the Commencement Date. The monthly base rent due under the Lease initially shall be $224,158 per month for the first year following the Rent Commencement Date and is scheduled to increase by approximately 3% per annum for each subsequent year. The Company has the option to extend the Lease one time for an additional five-year period, subject to the terms therein.

In connection with its entry into the Lease and as a security deposit, the Company has provided the landlord a letter of credit in the amount of approximately $1.4 million, which the Company and the landlord have agreed may be reduced to approximately $1.2 million following the third anniversary of the Rent Commencement Date, provided that no event of default by the Company has occurred. The landlord has the right to terminate the Lease upon customary events of default.

Option Exchange Program

On January 23, 2024, the Company initiated a tender offer related to a one-time stock option exchange program pursuant to which eligible non-executive officer employees are being given the opportunity to exchange certain outstanding stock options to purchase shares of the Company’s common stock for replacement options to purchase a lesser number of shares of common stock (the “Option Exchange”). Stock options eligible for exchange have an exercise price per share of $35.00 or greater, in addition to certain other requirements, and will be exchanged for replacement options with an exercise price per share equal to the fair market value of the Company’s common stock on the date of grant of the replacement options, which is currently expected to be February 21, 2024. Approximately 3.5 million outstanding stock options are eligible to be exchanged. All the replacement options will be granted in exchange for tendered options at ratios ranging from 1.50:1 to 5:00:1, depending on the current exercise price of the tendered option. Holders of eligible options may elect to tender their eligible options through the expiration of the offer period, which is currently expected to be February 20, 2024. The Company does not expect to incur significant additional stock-based compensation expense as a result of the Option Exchange. The consummation of the Option Exchange was subject to approval by the Company’s stockholders, which approval was received at the special meeting of stockholders held on January 31, 2024.