Accrued Liabilities (Tables)

12 Months Ended

Dec. 31, 2017

Payables and Accruals [Abstract]

Schedule of Accrued Liabilities

Accrued liabilities consist of the following (in thousands):

	DECEMBER 31,
	2017		2016
Research and development services	$	3,352	$	3,027
Legal and professional services	48		28
Employee compensation	2,777		1,880
Other	9		—
Total accrued liabilities	$	6,186	$	4,935