9. Commitments

In November 2010, the Company entered into a five-year, non-cancelable operating lease for office and laboratory space. In December 2011, the Company signed a lease amendment (the "2011 Lease Amendment") that expanded the leased premises beginning in the second quarter of 2012. The 2011 Lease Amendment also extended the term of the existing lease through June 30, 2017. The 2011 Lease Amendment includes a free rent period for the expansion premises and escalating rent payments. In July 2015, the Company signed another lease amendment (the "2015 Lease Amendment") that expanded the leased premises beginning in the third quarter of 2015. The 2015 Lease Amendment includes escalating rent payments and is effective through June 30, 2017. The Company is recognizing rent expense on a straight-line basis over the lease term. The lease agreement provides for a five-year extension upon the completion of the lease term.

Future minimum payments required under the non-cancelable operating lease as of December 31, 2015 are summarized as follows (in thousands):

Period Ending December 31,	Amount
2016	$	937
2017		467

Total minimum lease payments	$	1,404

Rent expense for the years ended December 31, 2015, 2014, and 2013 was $0.8 million, $0.7 million, and $0.7 million, respectively.