J. Commitments and Contingencies

Leases

The Company currently has a lease agreement with CRP/King 830 Winter L.L.C. for the rental of approximately 110,000 square feet of laboratory and office space at 830 Winter Street, Waltham, MA through March 2026. The Company uses this space for its corporate headquarters and other operations. The Company may extend the lease for two additional terms of five years. Pursuant to lease amendments executed in 2013, 2014, and 2015 the Company received construction allowances of $746,000, $1.1 million, and $186,000 respectively, to build out office and lab space to the Company’s specifications. The Company is required to pay certain operating expenses for the leased premises subject to escalation charges for certain expense increases over a base amount.

In 2016, the Company entered into a lease agreement with PDM 930 Unit, LLC for the rental of 10,281 square feet of additional office space at 930 Winter Street, Waltham, MA through August 31, 2021. The Company received $617,000 as a construction allowance to build out the office space to the Company’s specifications. The Company is required to pay certain operating expenses for the leased premises based on its pro-rata share of such expenses for the entire rentable space of the building. The Company is actively seeking to sub-lease this space.

The Company also leases 43,850 square feet of manufacturing and office space at 333 Providence Highway, Norwood, MA under an agreement through June 30, 2018. The Company is required to pay certain operating expenses for the leased premises subject to escalation charges for certain expense increases over a base amount.

Effective in 2013, the Company entered into a lease agreement with River Ridge Limited Partnership for the rental of 7,507 square feet of additional office space at 100 River Ridge Drive, Norwood, MA. The initial term of the lease was for five years and two months commencing in July 2013 with an option for the Company to extend the lease for an additional term of five years. The Company is required to pay certain operating expenses for the leased premises subject to escalation charges for certain expense increases over a base amount. The Company has subleased this space through the remaining initial term of the lease.

Facilities rent expense, net of sublease income, was $6.8, $3.5, $6.5,and $6.0 million during the year ended December 31, 2017, the six months ended December 31, 2016 and fiscal years 2016 and 2015, respectively.

As of December 31, 2017, the minimum rental commitments, including real estate taxes and other expenses, for the next five years and thereafter under the non‑cancelable operating lease agreements discussed above are as follows (in thousands):


2018	$	7,703
2019		7,202
2020		7,251
2021		7,074
2022		7,125
Thereafter		23,531
Total minimum lease payments	$	59,886

There are no obligations under capital leases as of December 31, 2017, as all of the capital leases were single payment obligations which have all been made.

Collaborations and Licenses

The Company is contractually obligated to make potential future success‑based regulatory milestone payments in conjunction with certain collaborative agreements. These payments are contingent upon the occurrence of certain future events and, given the nature of these events, it is unclear when, if ever, the Company may be required to pay such amounts. Further, the timing of any future payment is not reasonably estimable. As of December 31, 2017, the maximum amount that may be payable in the future under the Company’s current collaborative agreements is $80 million.

Manufacturing Commitments

As of December 31, 2017, the Company has noncancelable obligations under several agreements related to in-process and future manufacturing of antibody and cytotoxic agents required for clinical supply of the Company’s product candidates totaling $3.5 million, all of which will be paid in calendar 2018.

In 2017, the Company executed a letter agreement with one of its antibody manufacturers to reserve capacity through calendar 2021. The total commitment over the five-year term of the agreement is €46.2 million, however only €13.9 million euros is noncancelable at December 31, 2017.

Litigation

The Company is not party to any material litigation.