Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Tables)

v3.6.0.2
Stockholders' Equity (Tables)
12 Months Ended
Dec. 31, 2016
Equity [Abstract]  
Schedule for accounting for share-based compensation
The following table summarizes stock-based compensation expense (in thousands):
 
December 31,
 
2016
 
2015
 
2014
Stock-based compensation expense as a component of:
 
 
 
 
 
Research and development expenses
$
8,836

 
$
4,080

 
$
3,595

General and administrative expenses
10,057

 
8,378

 
7,675

 
$
18,893

 
$
12,458

 
$
11,270

Stock option plan activity
Following is a summary of the Company’s stock option plan activity and related information:
 
 
Shares
 
Weighted
Average
Exercise
Price
 
Weighted
Average
Remaining
Contractual
Term in
Years
 
Aggregate
Intrinsic
Value
(In  thousands)
Balance at December 31, 2015
1,683,341

 
$
34.19

 
6.48
 
$
124,800

Granted
263,489

 
92.09

 
 
 
 
Exercised
(164,440
)
 
38.08

 
 
 
 
Forfeited
(28,115
)
 
60.17

 
 
 
 
Balance at December 31, 2016
1,754,275

 
42.12

 
6.19
 
104,247

Exercisable at December 31, 2016
1,298,561

 
30.21

 
5.44
 
92,723

Options vested and expected to vest as of December 31, 2016
1,752,275

 
$
42.12

 
6.19
 
$
104,247

Stock option plan activity, by exercise price range
Following is a further breakdown of the options outstanding as of December 31, 2016:
 
Range of exercise prices
Options
outstanding
 
Weighted
average
remaining  life
in years
 
Weighted average
exercise price
 
Options
exercisable
 
Weighted average
exercise price
$8.58 - $12.53
247,574

 
3.94
 
$
9.98

 
247,574

 
$
9.98

$10.12 - $12.81
76,100

 
4.92
 
11.38

 
76,100

 
11.38

$14.47 - $14.47
288,887

 
5.11
 
14.47

 
274,887

 
14.47

$16.14 - $21.00
106,242

 
1.85
 
17.76

 
106,242

 
17.76

$21.92 - $21.92
225,105

 
6.13
 
21.92

 
213,199

 
21.92

$32.00 - $53.34
72,330

 
6.02
 
36.18

 
62,747

 
34.73

$56.26 - $59.26
183,595

 
8.11
 
56.26

 
70,877

 
56.26

$63.58 - $68.62
26,382

 
7.50
 
67.20

 
21,976

 
67.50

$74.42 - $74.42
227,856

 
7.12
 
74.42

 
162,233

 
74.42

$85.79 - $138.53
298,204

 
9.03
 
93.19

 
62,726

 
89.71

$8.58 – $138.53
1,752,275

 
6.19
 
$
42.12

 
1,298,561

 
$
30.21

Stock option weighted average assumptions
The assumptions used for the specified reporting periods and the resulting estimates of weighted-average grant date fair value per share of options granted:

 
Year Ended December 31,
 
2016
 
2015
 
2014
 
Risk-free interest rate
1.3%-1.9%
 
1.7%-2.0%
 
1.9%
 
Expected volatility
48%-50%
 
50%-58%
 
62%-69%
 
Expected term
6.6 to 6.7 years
 
6.5 years
 
6.0 years
 
Forfeiture rate
5.00%
 
8.52%
 
8.6%-9.7%
 

Restricted stock activity
The following is a summary of the Company’s restricted stock activity and related information:
 
 
Shares
 
Weighted-Average
Grant Date Fair
Value
Outstanding at December 31, 2015
130,749

 
$
60.36

Granted
234,855

 
95.31

Vested
(54,421
)
 
66.79

Forfeited
(2,483
)
 
67.95

Outstanding at December 31, 2016
308,700

 
$
86.61