8. Commitments and Contingencies The Company leases office space in Waltham, Massachusetts under a non-cancelable operating lease agreement. In April 2015, the Company amended its lease to add an additional 17,700 square feet to its existing leased office space of 53,200 square feet, increasing the total to approximately 70,900 square feet. The term of the lease commenced April 1, 2013 and continues through June 30, 2017. The lease agreement provides for one month of free rent with respect to a portion of the leased premises and a tenant improvement allowance of $0.1 million. The Company recognizes rental expense on a straight-line basis over the respective lease term including any free rent periods and tenant allowances. Future minimum rental commitments under the lease as of September 30, 2015 were $0.6 million, $2.3 million and $1.2 million for the remainder of the year ending December 31, 2015, and the years ending December 31, 2016 and 2017, respectively. The Company has entered into agreements with certain vendors for the provision of services, including services related to data management, clinical and commercial operation support and companion diagnostic development, that the Company is not contractually able to terminate for convenience and avoid any and all future obligations to the vendors. Under such agreements, the Company is contractually obligated to make certain minimum payments to the vendors, with the exact amounts in the event of termination to be based on the timing of the termination and the exact terms of the agreement. The Company has certain obligations under licensing agreements with third parties that are contingent upon achieving various development, regulatory and commercial milestones. Pursuant to these license agreements, the Company is required to make milestone payments if certain development, regulatory and commercial sales milestones are achieved, and may have certain additional research funding obligations. Also, pursuant to the terms of each of these license agreements, when an