Stock-Based Compensation

3 Months Ended

Mar. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

8. Stock-Based Compensation

Employee and non-employee stock-based compensation expense is calculated based on the grant-date fair value of awards ultimately expected to vest, and recognized under the straight-line attribution method, assuming that all stock-based awards will vest. Forfeitures are recognized as they occur.

The following table summarizes stock-based compensation expense related to the Company’s stock-based awards for the periods indicated (in thousands):

	Three months ended March 31,
	2019		2018
Research and development	$	156	$	164
General and administrative		216		234
Employee stock-based compensation expense		372		398
Non-employee stock-based compensation expense		45		498
Total stock-based compensation expense	$	417	$	896