SHARE-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Schedule of Share-Based Compensation Expense

The following table sets forth the amount of share-based compensation expense recognized by the Company by line item on its Consolidated Statements of Operations and Comprehensive Loss for the years ended December 31, 2021, 2020 and 2019 (in thousands):

	Year ended December 31,
	2021		2020		2019
Research and development	$	973	$	350	$	188
General and administrative	4,170		1,407		1,049
Total Share Based Compensation	$	5,143	$	1,757	$	1,237

Schedule of the Status of Restricted Stock Units

A summary of the status of restricted stock units is presented below:

	Restricted Stock Units (in thousands)
Unvested at December 31, 2020	—
Granted RSU	2,482
Granted PSU	559
Unvested at December 31, 2021	3,041

Schedule of Stock Option Activity

The following table sets forth a summary of the Company’s total stock option activity, including awards granted under the 2014 Plan and 2009 Plan and inducement grants made outside of stockholder approved plans, for the years ended December 31, 2021, 2020 and 2019:

	Number of Shares under Option (in thousands)	Weighted-Average Exercise Price	Weighted-Average Remaining Contractual  Life (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2018	3,942	$2.12	9.14	$	57
Granted	3,986	$1.02
Exercised	(90)	$1.10
Canceled or forfeited	(1,602)	$1.78
Outstanding at December 31, 2019	6,236	$1.52	8.83	$	358
Granted	4,044	$0.87
Exercised	(12)	$1.13
Canceled or forfeited	(121)	$1.04
Outstanding at December 31, 2020	10,147	$1.26	8.50	$	3,160
Granted	8,273	$3.32
Exercised	(34)	$1.23
Canceled or forfeited	(2,683)	$3.70
Outstanding at December 31, 2021	15,703	$1.93	8.03	$	82
Exercisable at December 31, 2021	7,562	$1.65	7.41	$	59

Schedule of Weighted-Average Inputs and Assumptions in Black-Scholes Option

For the years ended December 31, 2021, 2020 and 2019, the grant-date fair value of stock options was determined using the following weighted-average inputs and assumptions in the Black-Scholes option pricing model:

	Year ended December 31,
	2021	2020	2019
Fair market value	$3.32	$0.87	$1.02
Grant exercise price	$3.32	$0.87	$1.02
Expected term (in years)	6.0	6.1	6.0
Risk-free interest rate	0.9%	1.3%	2.1%
Expected volatility	74.6%	71.5%	78.1%
Dividend yield	—%	—%	—%