Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Stock-based Compensation [Abstract]

Assumptions used in the black-Scholes model

	Year ended
	December 31, 2019
Risk-free interest rate	1.50 to 2.23%
Expected volatility	89.26 to 90.43%
Expected term (in years)	5.50 to 6.25
Expected dividend yield	0

Allocation of Stock-Based Compensation Expenses

	Year Ended December 31,
	2019		2018
Research and development	$	872,000	$	8,000
General and administrative		3,398,000		38,000
Total stock-based compensation	$	4,270,000	$	46,000

	Year Ended
	December 31,
	2019		2018
Expense related to RSA's issued prior to Merger and vesting beginning on Merger closing date	$	2,152,000	$	—
Acceleration of RSA expense in connection with executive severance		1,244,000		—
Expense related to vesting of stock options issued under the Company's stock plans		874,000		46,000
Total stock-based compensation expense	$	4,270,000	$	46,000

Summary of Stock Option Activity

	Options Outstanding
				Weighted
				Average
		Weighted		Remaining
		Average		Contractual	Aggregate
		Exercise		Term	Intrinsic
	Shares	Price		(Years)	Value
Outstanding at December 31, 2018	136,463	$	36.31	5.02		—
Assumed in the Merger	52,602		56.60			—
Granted	1,207,208		3.18			1,569,000
Forfeited/Cancelled	(120,893)		15.83			92,000
Outstanding at December 31, 2019	1,275,380	$	7.61	8.81		1,476,000
Vested and expected to vest at December 31, 2019	1,275,380	$	7.61	8.81	$	1,476,000
Exercisable at December 31, 2019	147,097	$	40.54	4.34	$	—

Schedule of restricted stock awards

		Weighted Avg
		Grant Date
	Shares	Fair Value
Outstanding at December 31, 2018	416,856	$	1.88
Granted	—		—
Forfeited/Cancelled	(44,255)		1.29
Issued as Common Stock	(29,108)		1.95
Outstanding at December 31, 2019	343,493	$	1.42

Shares Reserved for Future Issuance

	Shares Reserved
Stock options outstanding	1,275,380
Employee stock purchase plan	5,462
Available for future grants under the 2016 Plan	67,065
Warrants outstanding	1,854,007
Total shares reserved	3,201,914