10. Commitments and Contingencies Leases The Company has a lease for office space in Boston, Massachusetts, effective as of July 28, 2014, with a term expiring July 31, 2020. In March 2015, the Company entered into an operating lease for additional office space in Boston, Massachusetts, effective as of April 15, 2015, with a term expiring on July 31, 2020, and an option to extend this lease for three additional years. In addition, with the landlords consent, the Company has subleased 2,976 square feet of office space in Boston, Massachusetts to an unrelated third party beginning on January 1, 2017 and expiring on June 30, 2020, and the Company expects to receive approximately $0.2 million in sublease rental income from January 1, 2019 through the end of the sublease term. In October 2015, the Company entered into an operating lease for office space in San Diego, California, effective as of October 1, 2015, with a term expiring on September 30, 2019, and an option to extend this lease for five additional years . Future minimum lease payments for its operating leases as of December 31, 2018 were as follows: Year Ending December 31, (in thousands) 2019 $ 464 2020 226 2021  2022  $ 690 During the years ended December 31, 2018, 2017 and 2016, the Company recognized $0.4 million, $0.3 million and $0.4 million, respectively, of rental expense related to office space. Intellectual Property Licenses The Company has acquired exclusive rights to develop patented compounds and related know-how for beloranib under two licensing agreements with two third parties in the course of its research and development activities. The licensing rights obligate the Company to make payments to the licensors for license fees, milestones, license maintenance fees and royalties. The Company is also responsible for patent prosecution costs. As of December 31, 2018, the Company is obligated to make additional milestone payments of up to $12.3 million upon reaching certain pre-commercialization milestones, such as clinical trials and government approvals (including the U.S. Food and Drug Administration, or FDA, approval of a New Drug application, or NDA), and up to $12.5 million upon reaching certain product commercialization milestones related to the development of beloranib. Under one of the license agreements, the Company is also obligated to pay up to $1.3 million with respect to each subsequent licensed product, if any, that is a new chemical entity. In addition, the Company will owe single-digit royalties on sales of commercial products developed using these licensed technologies, if any. There were no milestones achieved during the years ended December 31, 2018, 2017 or 2016. The Company is also obligated to pay to the licensors a percentage of fees received if and when the Company sublicenses the technology. As of December 31, 2018, the Company has not yet developed a commercial product using the licensed technologies and it has not entered into any sublicense agreements for the technologies. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners, and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of management team and the board of directors of the Company that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of December 31, 2018. Legal Proceedings The Company accrues a liability for legal contingencies when it believes that it is both probable that a liability has been incurred and that the Company can reasonably estimate the amount of the loss. The Company reviews these accruals and adjusts them to reflect ongoing negotiations, settlements, rulings, advice of legal counsel and other relevant information. To the extent new information is obtained and the views on the probable outcomes of claims, suits, assessments, investigations or legal proceedings change, changes in the Companys accrued liabilities would be recorded in the period in which such determination is made. In addition, in accordance with the relevant authoritative guidance, for any matters in which the likelihood of material loss is at least reasonably possible, the Company will provide disclosure of the possible loss or range of loss. If a reasonable estimate cannot be made, however, the Company will provide disclosure to that effect. The Company expenses legal costs as they are incurred. The Company may periodically become subject to other legal proceedings and claims arising in connection with ongoing business activities, including claims or disputes related to patents that have been issued or that are pending in the field of research on which the Company is focused. Other than the above action, the Company is not aware of any other material claims as of December 31, 2018.