Stock-Based Compensation Plans (Tables)

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Summary of Stock Option Activity

The following table summarizes stock option activity since January 1, 2020 for the 2019 Plan:

	Options	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding as of January 1, 2020	456,645	$	12.57
Granted	25,118	$	8.30
Exercised	—	$	—
Forfeited or expired	(61,918)	$	13.47
Outstanding as of June 30, 2020	419,845	$	12.19	8.75	$	411,847
Options vested and expected to vest as of June 30, 2020	419,845	$	12.19	8.75	$	411,847
Options exercisable as of June 30, 2020	101,845	$	12.61	7.35	$	72,388

The following table summarizes stock option activity since January 1, 2020 for the Plans assumed from Vital:

	Options	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding as of January 1, 2020	14,403	$	306.01
Granted	—	$	—
Exercised	—	$	—
Forfeited or expired	—	$	—
Outstanding as of June 30, 2020	14,403	$	306.01	2.09	$	—
Options vested and expected to vest as of June 30, 2020	14,403	$	306.01	2.09	$	—
Options exercisable as of June 30, 2020	14,403	$	306.01	2.09	$	—

Schedule of Valuation Assumptions Used

The following are the underlying assumptions used in the Black-Scholes option pricing model to determine the fair value of stock options granted to employees and to non-employees under this stock plan:

	Six Months Ended June 30,
	2020
Risk-free interest rate	1.06%
Expected dividend yield	0%
Expected volatility	84.4%
Expected term of options (years)	5.76

Schedule of Stock-based Compensation Expense for Stock Awards Recognized

Total stock-based compensation expense for all stock awards recognized in the accompanying unaudited condensed consolidated statements of operations is as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Research and development	$	99	$	1,670	$	196	$	1,670
General and administrative	270		6,361		526		6,361
Total	$	369	$	8,031	$	722	$	8,031