E.Commitments and Contingencies

Leases

Effective July 27, 2007, the Company entered into a lease agreement with Intercontinental Fund III for the rental of approximately 89,000 square feet of laboratory and office space at 830 Winter Street, Waltham, MA through March 2020. The Company uses this space for its corporate headquarters and other operations. In December 2013, the Company modified its lease agreement at 830 Winter Street, Waltham, MA to include approximately 19,000 square feet of additional office space through 2020, concurrent with the remainder of the original lease term. As part of the lease amendment, the Company received a construction allowance of approximately $746,000 to build out office space to the Company’s specifications. The Company obtained physical control of the additional space to begin construction in January 2014. In April, 2014, the Company again modified its lease agreement at this site to extend the lease to 2026. The Company may extend the lease for two additional terms of five years. As part of this lease amendment, the Company received a construction allowance of approximately $1.1 million to build out office 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. The Company entered into a sublease in December 2009 for 14,100 square feet of this space in Waltham through January 2015; however, the Company and the sublessee agreed to end the lease term effective December 31, 2014.

Effective April 2012, the Company entered into a sublease agreement for the rental of 7,310 square feet of laboratory and office space at 830 Winter Street, Waltham, MA from Histogenics Corporation, the term of which expires in May 2015. 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 also leases manufacturing and office space at 333 Providence Highway, Norwood, MA under an agreement through 2018 with an option 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.

Effective April 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 is 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 entered into a sublease in December 2014 for this space, effective January 2015 through July 2018.

The minimum rental commitments for the Company’s facilities, including real estate taxes and other expenses, for the next five fiscal years and thereafter under the non-cancelable operating lease agreements discussed above are as follows (in thousands):

2015 (three months remaining)	$	1,781
2016	6,926
2017	6,942
2018	7,048
2019	6,237
Thereafter	43,900
Total minimum lease payments	$	72,834
Total minimum rental payments from sublease	(395		)
Total minimum lease payments, net	$	72,439

There are no obligations under capital leases as of March 31, 2015, as all of the capital leases were single payment obligations which have all been made.

Collaborations

The Company is contractually obligated to make potential future success-based development, regulatory or sales 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 March 31, 2015, the maximum amount that may be payable in the future under the Company’s current collaborative agreements is $162 million, $1.4 million of which is reimbursable by a third party under a separate agreement.