Equity Incentive Plans (Tables)

9 Months Ended

Sep. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Equity Award Activity

The activity related to equity awards, which are comprised of stock options, during the nine months ended September 30, 2021 is summarized as follows:

	Equity Awards			Weighted- average Exercise Price per Share		Weighted- average Remaining Contractual Term(1) (years)		Aggregate Intrinsic Value(2) (millions)
Outstanding at December 31, 2020		4,121,666		$	8.67
Granted		876,991		$	4.66
Exercised		(29,677	)	$	5.21
Cancelled/forfeited		(831,466	)	$	10.00
Outstanding at September 30, 2021		4,137,514		$	7.56		8.3	$	0.1
Exercisable at September 30, 2021		1,191,395		$	14.61		6.3	$	-

⁽¹⁾ Represents the weighted-average remaining contractual term of stock options.

⁽²⁾ Aggregate intrinsic value represents the product of the number of equity awards outstanding or equity awards exercisable multiplied by the difference between the Company’s closing stock price per share on the last trading day of the period, which was $3.99 as of September 30, 2021, and the exercise price.

Share-based Compensation Expense

The classification of share-based compensation expense is summarized as follows (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2021		2020		2021		2020
Selling, general and administrative	$	894	$	697	$	2,711	$	2,167
Research and development		281		691		604		3,218
Total share-based compensation expense	$	1,175	$	1,388	$	3,315	$	5,385