7. Commitments and Contingencies

Facility Leases

The Company is currently leasing its facility which has approximately 68,400 square feet of manufacturing, research laboratory and office space. In July 2016, the term of the lease was extended for 16 months through December 2018. The Company has the option to renew the lease for three additional five-year periods beyond its expiration.

The lease related to the facility is treated as an operating lease. The minimum annual rent on the facility is subject to increases specified in the lease. The Company is also required to pay taxes, insurance and operating costs under the facility lease. The Company recognizes level monthly rent for its facility lease over the entire lease period. The monthly rent is calculated by adding the total rent payments over the entire lease period and then dividing the result by the total term of the lease. The $0.4 million difference between the base rent paid and the rent expensed through December 31, 2017 is recorded as prepaid rent in the balance sheet. Rent expense for the years ended December 31, 2017, 2016 and 2015 was $2.4 million, $2.6 million, and $2.8 million, respectively.

At December 31, 2017, future minimum rental payments due under the Company’s facilities lease were as follows (in thousands):

Year ending December 31,
2018	$	2,411
2019		—
2020		—
2021		—
2022		—
Thereafter		—
Total lease payments	$	2,411

Other Contingencies

In the ordinary course of business, the Company may become a party to additional lawsuits involving various matters. The Company is unaware of any such lawsuits presently pending against it which, individually or in the aggregate, are deemed to be material to the Company’s financial condition or results of operations.

The Company prosecutes its intellectual property vigorously to obtain the broadest valid scope for its patents. Due to uncertainty of the ultimate outcome of these matters, the impact on future operating results or the Company’s financial condition is not subject to reasonable estimates.