XML 39 R22.htm IDEA: XBRL DOCUMENT v3.8.0.1
Equity Plans and Stock-Based Compensation (Tables)
9 Months Ended
Sep. 30, 2017
Share Based Compensation [Abstract]  
Option Activity under Stock-Based Compensation Plans

Option activity under our stock-based compensation plans during the nine months ended September 30, 2017 was as follows (in thousands except per share amounts):

 

 

 

Shares Underlying  Outstanding Options

(in thousands)

 

 

Weighted-Average Exercise

Price Per Share

 

 

Weighted-Average Remaining Contractual Term (years)

 

 

Aggregate Intrinsic Value

(in thousands)

 

Balance at December 31, 2016

 

 

3,975

 

 

$

21.38

 

 

 

 

 

 

 

 

 

Options granted

 

 

329

 

 

$

6.99

 

 

 

 

 

 

 

 

 

Options exercised

 

 

(50

)

 

$

11.82

 

 

 

 

 

 

 

 

 

Options cancelled:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Options forfeited (unvested)

 

 

(351

)

 

$

18.43

 

 

 

 

 

 

 

 

 

Options cancelled (vested)

 

 

(217

)

 

$

29.11

 

 

 

 

 

 

 

 

 

Balance at September 30, 2017

 

 

3,686

 

 

$

20.05

 

 

 

5.79

 

 

$

13,420

 

Vested and expected to vest at September 30, 2017

 

 

3,671

 

 

$

20.06

 

 

 

5.79

 

 

$

13,390

 

Exercisable at September 30, 2017

 

 

2,394

 

 

$

22.18

 

 

 

5.40

 

 

$

5,948

 

 

Summary of Restricted Stock Units Activity

Restricted stock unit activity under our stock-based compensation plans during the nine months ended September 30, 2017 was as follows (in thousands except per share amounts):

 

 

Number of Shares (In thousands)

 

 

Weighted-Average Grant-Date Fair Value

 

Non-vested as of December 31, 2016

 

699

 

 

$

12.12

 

Granted

 

2,136

 

 

 

4.83

 

Vested

 

(171

)

 

 

18.62

 

Forfeited or expired

 

(221

)

 

 

8.44

 

Non-vested as of September 30, 2017

 

2,443

 

 

$

5.62

 

 

Fair Value-Based Measurements and Weighted-Average Assumptions

The fair value-based measurements and weighted-average assumptions used in the calculations of these measurements are as follows:

 

 

Stock Options

 

 

Stock Options

 

 

Employee Stock Purchase Plan

 

 

Three Months Ended

 

 

Nine Months Ended

 

 

Nine Months Ended

 

 

September 30,

 

 

September 30,

 

 

September 30,

 

 

2017

 

 

2016

 

 

2017

 

 

2016

 

 

2017

 

 

2016

 

Weighted-average fair value

$

8.11

 

 

$

8.90

 

 

$

4.73

 

 

$

9.67

 

 

$

3.05

 

 

$

7.86

 

Risk-free interest rate

 

1.9

%

 

 

1.1

%

 

 

1.9

%

 

 

1.4

%

 

 

1.0

%

 

 

0.6

%

Expected life (in years)

 

4.5

 

 

 

4.5

 

 

 

4.5

 

 

 

4.9

 

 

 

1.2

 

 

 

1.2

 

Volatility

 

0.9

 

 

 

0.7

 

 

 

0.9

 

 

 

0.7

 

 

 

1.0

 

 

 

0.6

 

 

Stock-Based Compensation Expense

The components of stock-based compensation expense were (in thousands):

 

 

Three Months Ended

 

 

Nine Months Ended

 

 

September 30,

 

 

September 30,

 

 

2017

 

 

2016

 

 

2017

 

 

2016

 

Research and development

$

1,973

 

 

$

1,639

 

 

$

5,707

 

 

$

4,490

 

General and administrative

 

1,687

 

 

 

2,022

 

 

 

5,137

 

 

 

5,540

 

Total

$

3,660

 

 

$

3,661

 

 

$

10,844

 

 

$

10,030