8 . Commitments and Contingencies Leases On July 13, 2015, the Company entered into a sublease (the "Sublease") that became effective July 22, 2015, to sublet certain premises consisting of 10,141 square feet of space (the "Subleased Premises") located at 101 Hudson Street, Jersey City, New Jersey from Optimer Pharmaceuticals, Inc. The term of the Sublease commenced on August 1, 2015 (the "Commencement Date") and expired on July 30, 2018. No base rent was due under the Sublease until one month after the Commencement Date. Under the Sublease, the Company was obligated to pay monthly base rent of approximately twenty-five thousand dollars per month, which amount increases by 3% annually on each anniversary of the Commencement Date. In addition, the Company was required to fund a security deposit with the sublandlord in the amount of $0.1 million. On March 1, 2018, the Company entered into a long-term lease agreement for approximately 19,275 square feet of office space in Jersey City, New Jersey. The lease term is eleven years from the commencement date with total lease payments of $7.3 million over the lease term. The Company has the option to renew for two consecutive five-year periods from the end of the first term. Under the lease, the Company must furnish a security deposit in the form of a standby letter of credit in the amount of $0.3 million, which will be reduced by fifty-five thousand dollars every two years for ten years after the commencement of the lease. The security deposit is classified as restricted cash in the accompanying balance sheets . Rent expense was approximately $0.5 million and $0.3 million for the years ended December 31, 2018 and 2017, respectively. Future minimum lease payments for all operating leases as of December 31, 2018 are as follows (in thousands): 2019 498 2020 508 2021 518 2022 529 2023 716 Thereafter 4,203 Total $ 6,972 License Arrangements with Potential Future Expenditures As of December 31, 2018, the Company had a license arrangement with Merck Sharp &amp; Dohme Corp., or Merck, as amended, that involves potential future expenditures. Under the license arrangement, executed in May 2013, the Company exclusively licensed from Merck its rights to ibrexafungerp in the field of human health. In January 2014, Merck assigned the patents related to ibrexafungerp that it had exclusively licensed to the Company. Ibrexafungerp is the Company's lead product candidate. Pursuant to the terms of the license agreement, Merck is eligible to receive milestone payments from the Company that could total $19.0 million upon occurrence of specific events, including initiation of a Phase 3 clinical study, new drug application, and marketing approvals in each of the U.S., major European markets, and Japan. In addition, Merck is eligible to receive tiered royalties from the Company based on a percentage of worldwide net sales of ibrexafungerp. The aggregate royalties are mid- to high-single digits. In December 2014, the Company and Merck entered into an amendment to the license agreement that deferred the remittance of a milestone payment due to Merck, such that no amount would be due upon initiation of the first Phase 2 clinical trial of a product containing the ibrexafungerp compound (the "Deferred Milestone"). The amendment also increased, in an amount equal to the Deferred Milestone, the milestone payment that would be due upon initiation of the first Phase 3 clinical trial of a product containing the ibrexafungerp compound. In December 2016 and January 2018, the Company entered into second and third amendments to the license agreement with Merck which clarified what would constitute the initiation of a Phase 3 clinical trial for the purpose of milestone payment. Except as described above, all other terms and provisions of the license agreement remain in full force and effect. In January 2019, a milestone payment became due to Merck as a result of the initiation of the VANISH Phase 3 VVC program and was paid in March 2019. The Company has two additional licensing agreements for other compounds that could require it to make payments of up to $2.3 million upon achievement of certain milestones by the Company. Clinical Development Arrangement The Company has entered into, and expects to continue to enter into, contracts in the normal course of business with various third parties who support its clinical trials, preclinical research studies, and other services related to its development activities. The scope of the services under these agreements can generally be modified at any time, and the agreement can be terminated by either party after a period of notice and receipt of written notice. Legal Proceeding On March 8, 2017, a purported stockholder class action lawsuit was filed in the United States District Court for the District of New Jersey against the Company and certain of its current and former officers, captioned Gibson v. Scynexis, Inc., et al. On October 26, 2018, the class action lawsuit was dismissed.