Prepaid Expenses

9 Months Ended

Sep. 30, 2018

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Prepaid Expenses

7. Prepaid expenses

As of September 30, 2018, prepaid expenses were $4,218, consisting of $3,466 of prepaid R&D clinical costs, $505 of prepaid insurance and $247 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.