Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

Schedule of employee stock-based compensation expense

The stock-based compensation expense recorded for the three and nine months ended September 30, 2017 and 2016 is as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Research and development	$	85	$	135	$	269	$	309
General and administrative		861		798		2,549		2,097
Total stock-based compensation expense	$	946	$	933	$	2,818	$	2,406

Schedule of outstanding potentially dilutive securities calculation of diluted loss per share attributable to common stockholders

The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted loss per share attributable to common stockholders (in common stock equivalent shares):

	September 30,
	2017		2016
Series A convertible preferred stock		—		400,000
Series B convertible preferred stock		—		483,609
Common stock purchase warrants		829,285		750,185
Restricted stock units		344,982		—
Common stock options		1,558,800		1,321,300
Total		2,733,067		2,955,094