STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Sep. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Awards Granted

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

	For the Three Months Ended September 30,								For the Nine Months Ended September 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		91,200	$	42.62		97,240	$	73.88		1,522,947	$	48.50		1,256,064	$	59.08
Restricted stock units		47,594	$	83.37		49,430	$	148.63		774,201	$	86.34		592,867	$	119.36

Summary of Stock-Based Compensation Expense by Function Included within Condensed Consolidated Statements of Operations and Comprehensive Loss

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 September 30,				For the Nine Months Ended September 30,
		2021		2020		2021		2020
	(in thousands)
Research and development		$	12,031	$	10,645	$	36,017	$	31,034
Selling, general and administrative			14,653		16,258		48,144		47,509
Total stock-based compensation expense		$	26,684	$	26,903	$	84,161	$	78,543

Summary of Stock-Based Compensation Expense by Grant Type Included within Consolidated Statements of Operations and Comprehensive Loss

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 September 30,				For the Nine Months Ended September 30,
		2021		2020		2021		2020
	(in thousands)
Stock options		$	13,912	$	16,474	$	48,518	$	49,677
Restricted stock awards/units			11,695		8,950		32,199		24,047
Employee stock purchase plan			1,077		1,479		3,444		4,819
Total stock-based compensation expense		$	26,684	$	26,903	$	84,161	$	78,543