Leases	3 Months Ended
Mar. 31, 2019
Leases [Abstract]
Leases	3. Leases The Company adopted the new leasing standards on January 1, 2019, using the modified retrospective transition method, which does not require restatement of prior periods, for all the leases existing as of the adoption date. The adoption of the new leasing standards did not have a significant impact on the Company’s consolidated financial statements. As of January 1, 2019, the Company’s only existing lease is the lease of its principal research and office space located at One Kendall Square in Cambridge, Massachusetts, which expires in June 2019. As of March 31, 2019, the Company has recorded a right-of-use asset of $1.0 million, within prepaid expenses and other current assets on its condensed consolidated balance sheet, which represents the Company’s right to use the underlying asset for the lease term. The Company also recorded a lease liability of $1.6 million, within accounts payable, accrued expenses and other, which represents the Company’s obligation to make lease payments arising from the associated lease. The right-of-use asset and lease liability are calculated using the present value of the lease payments over the expected lease term discounted at an incremental borrowing rate that the Company would expect to incur for a fully collateralized loan over a similar term under similar economic conditions. Certain adjustments to the right-of-use asset are required for items such as initial direct costs, prepaid rent and lease incentives.

Leases

3 Months Ended

Mar. 31, 2019

3. Leases

The Company adopted the new leasing standards on January 1, 2019, using the modified retrospective transition method, which does not require restatement of prior periods, for all the leases existing as of the adoption date. The adoption of the new leasing standards did not have a significant impact on the Company’s consolidated financial statements. As of January 1, 2019, the Company’s only existing lease is the lease of its principal research and office space located at One Kendall Square in Cambridge, Massachusetts, which expires in June 2019.

As of March 31, 2019, the Company has recorded a right-of-use asset of $1.0 million, within prepaid expenses and other current assets on its condensed consolidated balance sheet, which represents the Company’s right to use the underlying asset for the lease term. The Company also recorded a lease liability of $1.6 million, within accounts payable, accrued expenses and other, which represents the Company’s obligation to make lease payments arising from the associated lease. The right-of-use asset and lease liability are calculated using the present value of the lease payments over the expected lease term discounted at an incremental borrowing rate that the Company would expect to incur for a fully collateralized loan over a similar term under similar economic conditions. Certain adjustments to the right-of-use asset are required for items such as initial direct costs, prepaid rent and lease incentives.