Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Payments (Tables)

Stock-Based Payments (Tables)

3 Months Ended

Mar. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of status of stock options and changes during the period

A summary of the status of stock options as of December 31, 2018 and March 31, 2019 and changes during the three months ended March 31, 2019 is presented below:

								Aggregate
				Weighted		Remaining		Intrinsic
				Average		Contractual		Value
	Shares			Exercise Price		Life (in years)		(in thousands)
Outstanding at December 31, 2018		3,732,643		$	9.88	7.9		$	1,694
Granted		953,800			6.78
Exercised		(1,077	)		2.86
Cancelled		(68,971	)		11.71
Outstanding at March 31, 2019		4,616,395		$	9.21		8.2	$	6,335
Exercisable at March 31, 2019		1,726,979		$	8.82		7.0	$	3,362

Summary of status of restricted stock units and changes during the period

A summary of the status of restricted stock units as of December 31, 2018 and March 31, 2019 and changes during the three months ended March 31, 2019 is presented below:

				Weighted
				Average Grant
	Shares			Date Fair Value
Outstanding at December 31, 2018		—		$	—
Granted		1,082,124			6.71
Vested		—			—
Forfeited		(3,300	)		6.71
Outstanding at March 31, 2019		1,078,824		$	6.71

Schedule of weighted-average assumptions used in Black-Scholes option-pricing model

The fair value of each stock option granted was estimated on the date of grant using the Black-Scholes option-pricing model based on the following weighted-average assumptions:

	Three Months Ended March 31,
	2019			2018
Weighted-average risk-free interest rate		2.54	%		2.41	%
Expected dividend yield		—	%		—	%
Expected option term (in years)		6.08			6.08
Volatility		91.68	%		90.20	%

Summary of stock-based compensation expense for stock options granted to employee and non-employees

The following table summarizes the stock-based compensation expense for stock options and restricted stock units granted to employees and non-employees recorded in the Company’s condensed consolidated statements of operations:

		Three Months Ended March 31,
	2019			2018
Research and development		$	697		$	565
General and administrative			1,182			1,131
Total stock-based compensation expense		$	1,879		$	1,696