Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Tables)

v3.10.0.1
Stockholders' Equity (Tables)
12 Months Ended
Dec. 31, 2018
Equity [Abstract]  
Schedule of Accounting for Share-Based Compensation
The following table summarizes share-based compensation expense (in thousands):
December 31,
2018 2017 2016
Share-based compensation expense as a component of:
Research and development expenses $ 8,352  $ 14,235  $ 8,836 
General and administrative expenses 12,494  10,680  10,057 
$ 20,846  $ 24,915  $ 18,893 
Schedule of Stock Option Plan Activity
Following is a summary of our 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, 2017 1,876,332  $ 53.17  5.77 $ 157,340 
Granted 228,362  162.00 
Exercised (358,162) 55.24 
Forfeited (10,228) 114.53 
Balance at December 31, 2018 1,736,304  66.71  5.47 125,858 
Exercisable at December 31, 2018 1,313,374  47.03  4.56 117,314 
Options vested and expected to vest as of December 31, 2018 1,734,304  $ 66.71  5.47 $ 125,858 
Schedule of Stock Option Plan Activity by Exercise Price Range
Following is a further breakdown of the options outstanding as of December 31, 2018:
 
Range of exercise prices
Options
outstanding
Weighted
average
remaining  life
in years
Weighted average
exercise price
Options
exercisable
Weighted average
exercise price
$8.58 - $10.05 184,702  1.87 $ 10.00  184,702  $ 10.00 
$10.12 - $12.81 46,510  2.92 11.40  46,510  11.40 
$14.47 - $14.47 217,616  3.11 14.47  203,616  14.47 
$16.14 - $17.88 38,790  0.17 16.36  38,790  16.36 
$21.92 - $21.92 200,372  4.13 21.92  200,372  21.92 
$32.00 - $56.26 182,767  5.70 50.38  174,470  50.10 
$63.58 - $67.53 20,434  5.44 67.42  20,153  67.47 
$74.42 - $74.42 190,825  5.12 74.42  190,825  74.42 
$85.79 - $100.38 299,282  7.57 93.32  157,872  91.62 
$101.15 - $195.91 353,006  8.79 148.50  96,064  131.77 
1,734,304  5.47 $ 66.71  1,313,374  $ 47.03 
Schedule of 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,
  2018 2017 2016
Risk-free interest rate 2.7%-3.0% 2.0%-2.2% 1.3%-1.9%
Expected volatility 33%-36% 43%-47% 48%-50%
Expected term 5.1 to 5.8 years 6.5 to 6.8 years 6.6 to 6.7 years
Schedule of Restricted Stock Activity
The following is a summary of our restricted stock activity and related information:
 
Shares
Weighted-Average
Grant Date Fair
Value
Outstanding at December 31, 2017 133,294  $ 91.60 
Granted 62,133  169.92 
Vested (61,989) 86.19 
Forfeited (1,165) 125.16 
Outstanding at December 31, 2018 132,273  $ 130.63