STOCK-BASED COMPENSATION

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

12. STOCK-BASED COMPENSATION

The following table summarizes the Company’s stock awards granted for each of the periods indicated:

	For the Three Months Ended June 30,								For the Six Months Ended June 30,
	2021				2020				2021				2020
	Grants		Weighted Average Grant Date Fair Value		Grants		Weighted Average Grant Date Fair Value		Grants		Weighted Average Grant Date Fair Value		Grants		Weighted Average Grant Date Fair Value
Stock options		72,110	$	39.79		73,494	$	73.16		1,431,747	$	48.87		1,158,824	$	57.84
Restricted stock units		37,240	$	75.30		44,527	$	143.84		726,607	$	86.53		543,437	$	116.70

Stock-based Compensation Expense

For the three months ended June 30, 2021 and 2020, total stock-based compensation expense was $29.0 million and $27.6 million, respectively. For the six months ended June 30, 2021 and 2020, total stock-based compensation expense was $57.5 million and $51.6 million, respectively. The following table summarizes stock-based compensation expense by function included within the unaudited condensed consolidated statements of operations and comprehensive loss:

		For the Three Months Ended June 30,				For the Six Months Ended June 30,
		2021		2020		2021		2020
	(in thousands)
Research and development		$	12,860	$	11,140	$	23,986	$	20,389
Selling, general and administrative			16,109		16,476		33,491		31,251
Total stock-based compensation expense		$	28,969	$	27,616	$	57,477	$	51,640

The following table summarizes stock-based compensation expense by grant type included within the unaudited condensed consolidated statements of operations and comprehensive loss:

		For the Three Months Ended June 30,				For the Six Months Ended June 30,
		2021		2020		2021		2020
	(in thousands)
Stock options		$	17,587	$	17,848	$	34,606	$	33,203
Restricted stock awards/units			10,573		8,352		20,504		15,097
Employee stock purchase plan			809		1,416		2,367		3,340
Total stock-based compensation expense		$	28,969	$	27,616	$	57,477	$	51,640