Equity Incentive Plans (Tables)

6 Months Ended

Jun. 30, 2020

Equity Incentive Plans [Abstract]

Assumptions used in the black-Scholes model

The assumptions used in the Black-Scholes model are presented below:

	Six Months Ended
	June 30, 2020	June 30, 2019
Risk-free interest rate	0.46% - 1.51%	2.20 to 2.21%
Expected volatility	90.43%	89 to 90%
Expected term (in years)	5.75 - 6.25	5.75 to 6.25
Expected dividend yield	0%	0%

Allocation of Stock-Based Compensation Expenses

The tables below summarize the total stock-based compensation expense included in the Company’s consolidated statements of operations for the periods presented:

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Research and development	$	299,000	$	251,000	$	636,000	$	251,000
General and administrative		607,000		473,000		1,314,000		474,000
Total stock-based compensation	$	906,000	$	724,000	$	1,950,000	$	725,000

Summary of Stock Option Activity

Stock option transactions during the six months ended June 30, 2020 are presented below:

	Options Outstanding
				Weighted
				Average
		Weighted		Remaining
		Average		Contractual	Aggregate
		Exercise		Term	Intrinsic
	Shares	Price		(Years)	Value
Outstanding at December 31, 2019	1,275,380	$	7.61	8.81		—
Granted	241,666		3.55	—		—
Forfeited/Cancelled	(42,029)		10.01	—		—
Outstanding at June 30, 2020	1,475,017	$	6.74	8.35	$	923,000
Vested and expected to vest at June 30, 2020	1,475,017	$	6.74	8.35	$	923,000
Exercisable at June 30, 2020	455,950	$	14.40	6.71	$	242,000

Schedule of restricted stock awards

Restricted stock award transactions under the Assumed 2016 Plan during the six months ended June 30, 2020 are presented below:

		Weighted Avg
		Grant Date
	Shares	Fair Value
Outstanding at December 31, 2019	343,493	$	21.83
Forfeited/Cancelled	(4,010)		16.02
Issued as Common Stock	(76,925)		15.50
Outstanding at June 30, 2020	262,558	$	23.76

Shares Reserved for Future Issuance

As of June 30, 2020, the Company had reserved shares of its common stock for future issuance as follows:

	Shares Reserved
Stock options outstanding	1,475,017
Employee stock purchase plan	7,605
Available for future grants under the 2016 Plan	360,111
Warrants outstanding	10,547,363
Total shares reserved	12,390,096