Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2022

Stock-Based Compensation Expense

The following table presents stock-based compensation expense in the Company’s consolidated statements of comprehensive income:

	Three Months Ended  June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
	(Amounts in thousands)
Cost of product revenue	$	615	$	449	$	1,237	$	955
Research and development		622		795		1,421		1,511
Selling, general and administrative		5,748		5,899		12,242		11,218
Total stock-based compensation	$	6,985	$	7,143	$	14,900	$	13,684

Summary of Option Activity

Information regarding option activity for the six months ended June 30, 2022 under the Plans is summarized below:

	Shares			Weighted average exercise price		Weighted- Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value (in Thousands)
Options outstanding at December 31, 2021		625,107		$	54.15		6.29	$	131,707
Granted		47,838		$	180.82
Exercised		(16,399	)	$	28.20
Forfeited/expired/cancelled		(8,000	)	$	193.86
Options outstanding at June 30, 2022		648,546		$	62.42		6.09	$	67,377
Options exercisable at June 30, 2022		381,399		$	46.21		5.49	$	44,750
Vested and expected to vest at June 30, 2022(1)		632,147					6.08	$	65,687

(1)Represents the number of vested options as of June 30, 2022 plus the number of unvested options expected to vest as of June 30, 2022 based on the unvested outstanding options at June 30, 2022 adjusted for estimated forfeiture rates of 8% for awards granted to non-executive level employees and 3% for awards granted to executive level employees.

Summary of Restricted Stock Unit Activity

Information regarding stock unit activity, which includes activity for RSUs and performance stock units, for the six months ended June 30, 2022 under the Plans is summarized below:

	Shares			Weighted- Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value (in Thousands)
Unvested at December 31, 2021		606,685			3.07	$	160,674
Awarded		144,845
Vested		(175,647	)
Forfeited/expired/cancelled		(24,854	)
Unvested at June 30, 2022		551,029			3.00	$	89,487
Vested and expected to vest at June 30, 2022(1)		535,061			2.63	$	86,894

Represents the number of vested stock units as of June 30, 2022 plus the number of unvested stock units expected to vest as of June 30, 2022 based on the unvested outstanding stock units at June 30, 2022 adjusted for estimated forfeiture rates of 8% for awards granted to non-executive level employees and 3% for awards granted to executive level employees.