16. Commitments and Contingencies

Operating Leases

The Company leases its office, laboratory and manufacturing space under non-cancelable operating leases. During August 2012, the Company entered into an Indenture of Lease (the “Amended Lease”), which amended and restated its facility lease. The Amended Lease will terminate on June 30, 2019. In accordance with all related amendments, the Company leases in total approximately 112,300 square feet at its corporate headquarters located at One Kendall Square in Cambridge, Massachusetts.

As part of the Amended Lease and subsequent amendments, the landlord agreed to reimburse the Company for a portion of tenant improvements made to the facility. As of December 31, 2016, the Company had received $9.5 million of tenant improvement reimbursements. Tenant improvement reimbursements are recorded within deferred rent and are amortized over the term of the lease as reductions to rent expense.

In May 2016, the Company entered into a sublease agreement (the “Sublease”) whereby a subtenant agreed to lease 8,143 square feet of office and lab space from the Company. The Sublease terminates on June 30, 2019. Rental income received from the subtenant has been classified by the Company as reduction of rent expense. Total future minimum rental payments to be received by the Company from the subtenant as of December 31, 2017 are $0.4 million.

In connection with the completion of the Asset Sale, on April 3, 2017, the Company entered into a sublease with Ipsen, pursuant to which Ipsen is subleasing approximately 70,237 square feet of space in the Company’s Cambridge, Massachusetts facility through the end of the term of the lease on June 30, 2019.

Total rent expense was $3.6 million, $5.0 million and $4.3 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Future minimum lease commitments on non-cancelable operating leases and scheduled sublease payments as of December 31, 2017 are as follows:

Years ended December 31,	Gross Payments		Scheduled Sublease Payments		Net Payments
2018	$	7,438	$	4,016	$	3,422
2019		3,753		2,195		1,558
Total future minimum lease payments	$	11,191	$	6,211	$	4,980