COMMITMENTS AND CONTINGENCIES

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

On June 24, 2014, the Company entered into a lease agreement for completed office and laboratory space located in San Diego, California. The office space under the lease is the Company's corporate headquarters. The lease commenced in two phases (in July 2014 and March 2015) at a combined total initial monthly rent of $24,100 per month. The leased property is subject to a 3% annual rent increase following availability that results in the Company recording deferred rent over the term of the lease. In addition to such base monthly rent, the Company is obligated to pay certain customary amounts for its share of operating expenses and facility amenities. The original lease provided for expiration on January 31, 2018. On March 23, 2017, the Company entered into a First Amendment to Lease Agreement to amend the original lease agreement and to extend the term of the original lease for one year through January 31, 2019. On April 5, 2018, the Company entered into a Second Amendment to Lease Agreement to extend the lease term through January 31, 2020. Subsequently, on August 2, 2018, the Company entered into a Third Amendment to Lease Agreement to expand the size of the existing space for an additional base rent of $4,000 per month. All other terms and covenants from the original lease agreement remain unchanged.

Future minimum payments required under the lease are summarized as follows (in thousands):



Year Ending December 31:
2019	$	363
2020	30
Thereafter	—
Total minimum lease payments	$	393

Total lease expense for the years ended December 31, 2018, 2017 and 2016 was $0.8 million, $0.7 million, and $0.8 million, respectively.