Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Assumptions Used to Calculate Fair Value of Options Granted to Employees

The fair value of stock options granted to employees during the nine months ended September 30, 2019 and 2018 was estimated at the date of grant using the following assumptions:

	Nine Months Ended September 30,
	2019			2018
Risk-free interest rate		1.8	%	2.3 – 2.9%
Expected dividend yield		0	%	0%
Expected term	5.4 years			5.3 - 5.8 years
Expected volatility		67	%	62 – 64%

Schedule of Recognized Stock-Based Compensation Expense

The Company recognized stock-based compensation expense during the three and nine months ended September 30, 2019 and 2018 as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands)	2019		2018		2019		2018
Research and development expense	$	—	$	256	$	223	$	870
General and administrative expense		703		526		1,561		1,456
Total stock-based compensation expense	$	703	$	782	$	1,784	$	2,326