Share-Based Compensation

6 Months Ended

Jun. 30, 2020

Share-Based Compensation

Share-Based Compensation

12. Share-Based Compensation

Share-based compensation expense for all equity-based programs, including stock options, restricted stock units and the employee stock purchase plan, for the three and six months ended June 30, 2020 and 2019 was recognized in the accompanying Consolidated Statements of Operations and Comprehensive Loss as follows (in thousands):

	Three months ended June 30,				Six months ended June 30,
	2020		2019		2020		2019
Research and development	$	6,636	$	6,633	$	13,561	$	13,244
Selling, general and administrative		6,677		7,497		12,713		14,525
Total share-based compensation expense	$	13,313	$	14,130	$	26,274	$	27,769

We did not recognize a tax benefit related to share-based compensation expense during the three and six months ended June 31, 2020 and 2019, as we maintain net operating loss carryforwards and have established a valuation allowance against the entire net deferred tax asset as of June 30, 2020.

Stock Options

The following table summarizes the activity relating to our options to purchase common stock for the six months ended June 30, 2020:

				Weighted
		Weighted		Average	Aggregate
		Average		Remaining	Intrinsic
	Number of	Exercise		Contractual	Value
	Options	Price		Term (Years)	(Thousands)
Outstanding at December 31, 2019	6,287,025	$	42.24
Granted	870,492		7.61
Exercised	(24,153)		3.08
Forfeited	(346,100)		48.18
Outstanding at June 30, 2020	6,787,264	$	37.63	6.1	$	851
Vested and expected to vest at June 30, 2020	6,606,555	$	38.12	6.0	$	806
Vested and exercisable at June 30, 2020	4,912,792	$	44.14	5.0	$	350

The aggregate intrinsic value in the table above represents the pretax intrinsic value, based on our closing stock price of $6.75 as of June 30, 2020, which would have been received by the option holders had all option holders with in-the-money options exercised their options as of that date.

The following table summarizes information about our stock options as of and for the three and six months ended June 30, 2020 and 2019 (in thousands, except per share amounts):

	Three months ended June 30,				Six months ended June 30,
	2020		2019		2020		2019
Weighted-average grant date fair value per share	$	5.06	$	11.33	$	5.87	$	15.81
Intrinsic value of options exercised	$	87	$	198	$	91	$	963
Cash received from stock option exercises	$	72	$	222	$	74	$	1,316

As of June 30, 2020, the unrecognized share-based compensation expense related to unvested options, adjusted for expected forfeitures, was $28.2 million and the estimated weighted-average remaining vesting period was 1.8 years.

Restricted Stock

The following table summarizes the activity relating to our unvested restricted stock units (“RSUs”) for the six months ended June 30, 2020:

		Weighted
		Average
	Number of	Grant Date
	Units	Fair Value
Unvested at December 31, 2019	2,171,347	$	28.37
Granted	2,392,428		8.27
Vested	(775,784)		28.10
Forfeited	(276,398)		19.18
Unvested at June 30, 2020	3,511,593	$	15.46
Expected to vest after June 30, 2020	(3,351,795)	$	14.97

As of June 30, 2020, the unrecognized share-based compensation expense related to unvested RSUs, adjusted for expected forfeitures, was $49.1 million and the estimated weighted-average remaining vesting period was 2.3 years.