XML 33 R22.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock-Based Compensation (Tables)
9 Months Ended
Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Summary of Stock Option Activity

The following is a summary of stock option activity under the Plans (in thousands, except share and per share amounts):

 

 

 

Number of

Shares

 

 

Weighted-Average

Exercise Price Per

Share

 

 

Weighted-Average

Remaining

Contractual Term

(In years)

 

 

Aggregate Intrinsic

Value

 

Outstanding at December 31, 2017

 

 

3,785,083

 

 

$

7.31

 

 

 

6.88

 

 

$

1,989

 

Granted

 

 

1,542,250

 

 

 

5.66

 

 

 

 

 

 

 

 

 

Exercised

 

 

(395,245

)

 

 

3.90

 

 

 

 

 

 

 

1,294

 

Forfeited

 

 

(595,291

)

 

 

6.46

 

 

 

 

 

 

 

 

 

Cancelled

 

 

(100,202

)

 

 

13.73

 

 

 

 

 

 

 

 

 

Outstanding at September 30, 2018

 

 

4,236,595

 

 

 

6.99

 

 

 

7.17

 

 

 

8,570

 

Exercisable at September 30, 2018

 

 

2,308,545

 

 

 

7.74

 

 

 

5.59

 

 

 

5,222

 

Vested or expected to vest at September 30, 2018

 

 

3,775,876

 

 

 

7.14

 

 

 

6.92

 

 

 

7,731

 

 

Schedule of Estimated Assumptions Used to Calculate Weighted-Average Grant Date Fair Value of Options Granted

The weighted-average grant date fair values of stock options granted in the nine month periods ended September 30, 2018 and 2017 were $3.55 per share and $3.04 per share, respectively, and were calculated using the following estimated assumptions:

 

 

 

Nine Months Ended

 

 

 

September 30,

 

 

 

2018

 

 

2017

 

Weighted-average risk-free interest rate

 

 

2.66

%

 

 

1.98

%

Expected dividend yield

 

 

%

 

 

%

Expected volatility

 

 

68

%

 

 

63

%

Expected terms

 

6.0 years

 

 

6.0 years

 

 

Schedule of Nonvested Restricted Stock Units Activity

The following is a summary of restricted stock unit activity under the 2014 Plan (in thousands, except share and per share amounts):

 

 

 

Number of

Shares

 

 

Weighted-Average

Grant Date Fair

Value

 

Nonvested at December 31, 2017

 

 

606,497

 

 

 

5.23

 

Granted

 

 

1,217,190

 

 

 

5.06

 

Vested

 

 

(546,547

)

 

 

5.33

 

Forfeited

 

 

(75,017

)

 

 

5.63

 

Cancelled

 

 

 

 

 

 

Nonvested at September 30, 2018

 

 

1,202,123

 

 

 

4.99

 

 

Summary of Stock-Based Compensation Expense for Stock Options Granted that was Recorded in the Company's Results of Operations

The following table summarizes the stock-based compensation expense resulting from awards granted under stock incentive plans, including the 2014 ESPP, that was recorded in the Company’s results of operations for the periods presented (in thousands):

 

 

 

Three Months Ended

September 30,

 

 

Nine Months Ended

September 30,

 

 

 

2018

 

 

2017

 

 

2018

 

 

2017

 

Cost of product revenue

 

$

23

 

 

$

18

 

 

$

408

 

 

$

87

 

Research and development

 

 

409

 

 

 

340

 

 

 

1,271

 

 

 

1,047

 

Selling, general and administrative

 

 

1,601

 

 

 

862

 

 

 

5,561

 

 

 

2,555

 

Total stock-based compensation expense

 

$

2,033

 

 

$

1,220

 

 

$

7,240

 

 

$

3,689