Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of restricted stock unit activities

	Restricted Stock Units			Weighted Average Grant Date Fair Value
Non-vested as of December 31, 2021		96,201		$	28.87
Granted		143,425			6.79
Forfeited		(18,800	)		13.66
Vested		(49,513	)		21.42
Non-vested as of June 30, 2022		171,313		$	14.21

Schedule of stock option activities

	Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (1)
Outstanding as of December 31, 2021		1,356,639		$	20.51		8.59	$	1
Granted		767,350			6.44		-		-
Exercised		-			-		-		-
Forfeited		(234,078	)		15.70		-		-
Expired		(19,666	)		15.65		-		-
Outstanding as of June 30, 2022		1,870,245		$	15.39		8.23	$	-
Vested and expected to vest at June 30, 2022		1,870,245		$	15.39		8.23		-
Exercisable as of June 30, 2022		678,177		$	21.03		6.87	$	-

Schedule of total stock-based compensation costs

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2022		2021		2022		2021
Restricted stock units	$	390	$	1,360	$	704	$	2,663
Stock options		1,552		1,638		3,117		3,075
Total	$	1,942	$	2,998	$	3,821	$	5,738

Schedule of stock-based compensation expense

	For the Three Months ended June 30,				For the Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	423	$	453	$	789	$	724
General and administrative		1,519		2,545		3,032		5,014
Total	$	1,942	$	2,998	$	3,821	$	5,738