Stockholders’ Equity (Tables)

3 Months Ended

Mar. 31, 2020

Stockholders' Equity Note [Abstract]

Schedule of Stock-based Compensation Expense

Stock-based compensation is classified in the Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) as follows (in thousands): 

	Three Months Ended March 31,
	2020		2019
	(unaudited)
Employee:
Research and development	$	509	$	340
General and administrative	465		383
Non-Employee:
Research and development	11		29
General and administrative	1		2
Total stock-based compensation expense	$	986	$	754