Lease

In August 2013, the Company entered into an agreement to lease office and laboratory space in Lexington, Massachusetts under an operating lease with a commencement date of January 1, 2014 and a termination date of January 31, 2019. With the execution of this lease, the Company is required to maintain a $66,000 letter of credit as a security deposit, which is classified as a current asset within the consolidated balance sheets. In connection with the Lexington lease, the Company recorded $61,377 as prepaid rent as of December 31, 2016, with $31,916 recorded as a non-current asset. The Company also incurred a liability of $89,074 with respect to the Company’s contribution to the landlord’s leasehold improvements, of which $38,731 is outstanding as of December 31, 2016, with $19,876 recorded as a non-current liability. This liability is repayable as additional rent expense over the term of the lease and bears interest at 6%.

In December 2016, the Company entered into a one-year lease of office space in Miami, Florida, under an operating lease with a commencement date of December 1, 2016, and a termination date of November 30, 2017. In addition, the Company had leased office space in London, U.K., through March 2015, at which point it terminated in accordance with the terms of the lease.

The Company’s contractual commitments under all non-cancelable operating leases as of December 31, 2016, are as follows:

Rent expense is calculated on a straight-line basis over the term of the leases. Rent expense under the Company’s operating leases was $128,606 and $134,875 for the years ended December 31, 2016 and 2015, respectively.