SHARE BASED COMPENSATION

6 Months Ended

Jun. 30, 2020

Equity [Abstract]

SHARE BASED COMPENSATION

SHARE-BASED COMPENSATION

Restricted Shares

Service Based Restricted Stock Units

The following table summarizes the Company’s service based restricted stock unit activity during the six months ended June 30, 2020:

	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value
Unvested December 31, 2019	763,728	$	19.64
Granted	637,113	15.51
Vested	(173,117)	21.25
Forfeited/canceled	(68,414)	18.58
Unvested June 30, 2020	1,159,310	$	17.19

At June 30, 2020, unamortized stock compensation for service based restricted stock units was $16.9 million, with a weighted-average recognition period of 2.6 years.

Performance Based Restricted Stock Units

The following table summarizes the Company’s performance based restricted stock unit activity during the six months ended June 30, 2020:

	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value
Unvested December 31, 2019	233,500	$	20.90
Granted	150,000	15.46
Vested	(33,250)	25.75
Forfeited/canceled	(31,125)	17.56
Unvested June 30, 2020	319,125	$	18.16

At June 30, 2020, unamortized stock compensation for performance based restricted stock units was $1.9 million, with a weighted-average recognition period of 1.4 years.

Stock Options

The following table summarizes stock option activity during the six months ended June 30, 2020:

	Shares Underlying Options	Weighted Average Exercise Price	Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2019	7,371,733	$19.52	6.63	$	4,906
Granted	1,390,125	$15.48
Exercised	(35,042)	$12.31
Forfeited/canceled	(377,953)	$18.96
Outstanding at June 30, 2020	8,348,863	$18.90	6.79	$	28,920

At June 30, 2020, unamortized stock compensation for stock options was $31.5 million, with a weighted-average recognition period of 2.8 years.

At June 30, 2020, outstanding options to purchase 5.3 million shares of common stock were exercisable with a weighted-average exercise price per share of $19.20.

Share-Based Compensation

The following table sets forth total share-based compensation for the three and six months ended June 30, 2020 and 2019 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Research and development	$	2,332	$	1,896	$	4,458	$	3,566
Selling, general & administrative	3,622		3,852		7,406		8,702
Total	$	5,954	$	5,748	$	11,864	$	12,268