Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Relevant Data Used to Estimate Fair Value of Stock Option Grants

The relevant data used to determine the value of the stock option grants for the three months ended March 31, 2021 and 2020, were as follows:

	Three months ended
	March 31,
	2021		2020
Risk-free interest rates	1.12%		1.01% - 1.79%
Expected dividend yield	0.00%		0.00%
Expected term (in years)		6.0		6.0
Expected volatility	72.4%		65.4% - 66.3%

Summary of Stock Option Activity

The following table summarizes stock option activity for the three months ended March 31, 2021:

(In thousands, except per share amounts)	Shares Issuable Under Options			Weighted Average Exercise Price Per Share
Outstanding as of December 31, 2020		4,592		$	17.77
Granted		120			11.41
Exercised		(43	)		3.40
Cancelled		(56	)		19.81
Outstanding as of March 31, 2021		4,613		$	17.71
Options vested and expected to vest at March 31, 2021		4,613		$	17.71
Options exercisable at March 31, 2021		3,661		$	18.23

Summary of of RSU Activity

The following table summarizes the RSU activity for the three months ended March 31, 2021:

(In thousands, except per share amounts)	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Nonvested balance as of December 31, 2020		2,193		$	14.15
Granted		945			9.89
Vested/Released		(373	)		15.33
Cancelled		(79	)		13.51
Nonvested Balance as of March 31, 2021		2,686		$	12.51

Stock-Based Compensation Expense Related to Stock Options, and RSUs and Shares Purchased Under Employee Stock Purchase Plan

The Company recorded stock-based compensation expense related to stock options and RSUs and shares purchased under the Employee Stock Purchase Plan for the three months ended March 31, 2021 and 2020, as follows:

	For the three months ended March 31,
(In thousands)	2021		2020
Research and development	$	1,279	$	2,202
Selling, general and administrative		3,361		2,449
Total	$	4,640	$	4,651