Commitments and Contingencies

Leases

The Company conducts all operations in a facility under an operating lease which commenced in March 2012 and was originally scheduled to end in February 2015. During the first quarter of 2014, the lease was extended for an additional six years through February 2021, and includes a renewal option. During the second quarter of 2016, the Company amended the lease agreement to include additional space to be used primarily for administrative functions effective in May 2016. Lease payments include a fixed payment amount as well as contingent payments related to a proportionate share of operating and real estate expenses. At the inception of the lease, the lessor paid for leasehold improvements totaling $52 which has been capitalized and is being amortized over the lease term. The fixed payment amounts, including those in connection with the amended lease agreement in the second quarter of 2016, increase over the term of the lease but rent expense is recognized on a straight-line basis resulting in the recognition of deferred rent liability of $46 and $48 as of March 31, 2018 and December 31, 2017, respectively, calculated on the basis of the extended lease agreement.

Rent expense consisted of the following:



	Three Months Ended March 31,
	2018		2017
Straight-line rent expense	$	83	$	83
Contingent rent expense	89		77
Total rent expense	$	172	$	160

Future minimum lease payments as of March 31, 2018 are as follows:



Years ending December 31,	Operating Leases
2018	256
2019	347
2020	353
2021	59
Thereafter	—
Total	$	1,015

Northwestern University license agreements

On December 12, 2011, (1) AuraSense, LLC assigned to the Company all of its worldwide rights and interests under AuraSense, LLC’s 2009 license agreement with Northwestern University (“NU”) in the field of the use of nanoparticles, nanotechnology, microtechnology or nanomaterial-based constructs as therapeutics or accompanying therapeutics as a means of delivery, but expressly excluding diagnostics (the “assigned field”); (2) in accordance with the terms and conditions of this assignment, the Company assumed all liabilities and obligations of AuraSense, LLC as set forth in its license agreement in the assigned field; and (3) in order to secure this assignment and the patent rights from NU, the Company agreed (i) to pay NU an annual license fee, which may be credited against any royalties due to NU in the same year, (ii) to reimburse NU for expenses associated with the prosecution and maintenance of the license patent rights, (iii) to pay NU royalties based on any net revenue generated by the Company’s sale or transfer of any licensed product, and (iv) to pay NU, in the event the Company grants a sublicense under the licensed patent rights, the greater of a percentage of all sublicensee royalties or a percentage of any net revenue generated by a sublicensee’s sale or transfer of any licensed product. In August 2015, we entered into a restated license agreement with NU (the “restated license agreement”). In February 2016, we obtained exclusive license as to NU’s rights in certain SNA technology we jointly own with NU (the “February 2016 license agreement”). Our license to NU’s rights is limited to the assigned field, however we have no such limitation as to our own rights in this jointly owned technology. In June 2016, we entered into an exclusive license with NU to obtain worldwide rights to certain inhibitors of glucosylceramide synthase and their use in wound healing in diabetes (the “June 2016 license agreement”). Our rights and obligations in these 2016 agreements are substantially the same as in the restated license agreement from August 2015 (collectively referred to as “the Northwestern University License Agreements”). As of March 31, 2018, the Company has paid to NU an aggregate of $3,419 in consideration of each of the obligations described above.