8. Commitments and Contingencies Operating Lease In August 2017, the Company entered into a sublease with COI, a related party, for its corporate office and laboratory space in La Jolla, California (the 2017 Sublease). In November 2018, the Company amended the 2017 Sublease to provide the Company with a one-time right to terminate as of March 1, 2024, subject to certain conditions and fees. The 2017 Sublease, as amended, which expires in February 2027, contains rent escalations and the Company is required to pay for common area maintenance and other costs during the term of the lease. In connection with the 2017 Sublease, the Company recognized an operating lease right-of-use asset of $2.1 million as of March 31, 2019 and an aggregate lease liability of $2.2 million in its balance sheet. The remaining lease term is 7 years and 11 months, and the estimated incremental borrowing rate used by the Company to recognize the lease liability was 8.5%. The right to early terminate the lease was not recognized as part of the Companys lease liability and right-of-use lease asset. In addition, in September 2018, the Company entered into a noncancelable operating lease for additional corporate office and laboratory space (the Lease). The Lease commenced in November 2018 and will expire in February 2023, however, the Company has the option to extend the Lease for a 12-month period. The Lease provided for abatement of rent during the first four months of the lease, contains rent escalations and the Company is required to pay for common area maintenance and other costs during the term of the lease. In connection with the Lease, the Company recognized an operating lease right-of-use asset of $1.0 million as of March 31, 2019 and an aggregate lease liability of $1.2 million in its balance sheet. The remaining lease term is 4 years, and the estimated incremental borrowing rate used by the Company to recognize the lease liability was 7%. The option to extend the lease was not recognized as part of the Companys lease liability and right-of-use lease asset. Future minimum lease payments under the 2017 Sublease and the Lease as of March 31, 2019 are as follows (in thousands): 2019 $ 501 2020 655 2021 675 2022 727 2023 483 Thereafter 1,327 Total future minimum lease payments 4,368 Less interest (1,047 ) Total lease liability $ 3,321 Weighted average lease term 6.7 years Weighted average discount rate 8.0 % Operating lease costs were $0.3 million and $0.1 million for the three months ended March 31, 2019 and 2018, respectively. Contingencies From time to time, the Company becomes subject to claims or suits arising in the ordinary course of business. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. The Company had no such contingent liabilities as of March 31, 2019 or December 31, 2018, respectively.