Prepaid Expenses

3 Months Ended

Mar. 31, 2018

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Prepaid Expenses

7. Prepaid expenses

As of March 31, 2018, prepaid expenses were $3,431, consisting of $2,532 of prepaid R&D clinical costs, $706 of prepaid insurance and $193 of other prepaid costs. As of December 31, 2017, prepaid expenses were $1,635, consisting of $1,287 of prepaid R&D clinical costs, $124 of prepaid insurance, and $224 of other prepaid costs.