Stock-Based Compensation

9 Months Ended

Sep. 30, 2022

Stock-Based Compensation.

Stock-Based Compensation

Note 12—Stock-Based Compensation

Our stock option plans provide for the grant of incentive and non-qualified stock options, restricted stock awards, RSUs, warrants and other stock awards to employees, non-employee directors and consultants.

Stock-based compensation is as follows:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2022		2021		2022		2021
	(In thousands)
Continuing operations
Research and development	$	1,672	$	2,444	$	4,777	$	5,284
Selling, general and administrative		2,200		2,906		6,170		6,038
Total stock-based compensation in continuing operations		3,872		5,350		10,947		11,322
Discontinued operations		(28)		344		(139)		760
Total stock-based compensation	$	3,844	$	5,694	$	10,808	$	12,082

The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The following assumptions were applied to all stock option grants:

	Three Months Ended			Nine Months Ended
	September 30, 2022			September 30, 2022
Estimated weighted-average fair value	$	2.97		$	2.93
Weighted-average assumptions:
Expected volatility		89	%		88	%
Expected life, in years		6.0			6.0
Risk-free interest rate		2.83	%		2.81	%
Expected dividend yield		—	%		—	%

Stock option activity for all stock plans and related information is as follows:

		Weighted-
		Average			Aggregate
		Exercise		Remaining	Intrinsic
	Options	Price per		Contractual Life	Value
	Outstanding	Share		(In years)	(In thousands)
Balance at December 31, 2021	12,709,887	$	12.61
Granted	2,631,334		3.96
Exercised	(101,160)		4.10
Forfeited	(574,203)		13.58
Balance at September 30, 2022	14,665,858	$	11.08	5.7	$	78
Vested and expected to vest at September 30, 2022	14,202,672	$	11.16	5.6	$	70
Exercisable at September 30, 2022	10,277,595	$	12.11	4.2	$	—

As of September 30, 2022, there were 4.4 million unvested options outstanding that will vest over a weighted-average period of 2.4 years. The total estimated compensation expense yet to be recognized on outstanding options is $22.6 million.

The Company has 200,000 unvested RSUs outstanding as of September 30, 2022 that vest 50% on December 1, 2022 and 50% on December 1, 2023.