7. SHARE-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Share-based Compensation Expense by Line Item

The following table summarizes the amount of share-based compensation expense by line item on the statements of operations:

Share-based compensation expense		Three Months Ended				Six Months Ended
		June 30,				June 30,
(in thousands)		2022		2021		2022		2021
Research and development expense	$	2,018	$	2,201	$	3,851	$	3,387
Sales, marketing, general and administrative expense		2,102		5,696		4,003		6,148
	$	4,120	$	7,897	$	7,854	$	9,535

Option Positions

The following table summarizes shares, weighted-average exercise price, weighted-average remaining contractual term and aggregate intrinsic value of options outstanding and options exercisable as of June 30, 2022:

				Weighted-
			Weighted-	Average
			Average	Remaining		Aggregate
Options			Exercise	Contractual		Intrinsic
	Shares		Price	Term (years)		Value
Outstanding as of June 30, 2022	1,153,000	$	1.30	5.7	$	3,003,000
Exercisable as of June 30, 2022	982,000	$	1.42	5.5	$	2,451,000

Restricted Stock Unit Activity

The following table summarizes activity and positions with respect to RSUs and PSUs for the six months ended June 30, 2022:

			Weighted-average
	Shares		price
Unvested as of December 31, 2021	2,625,000	$	13.05
Granted	8,367,000		2.24
Vested	(794,000)		11.83
Forfeited	(410,000)		12.80
Unvested as of June 30, 2022	9,788,000	$	3.92