Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Tables)

v3.4.0.3
Stock Based Compensation (Tables)
 3 Months Ended
Mar. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Stock-Based Compensation Expense

Stock-based compensation expense, which consists of the compensation cost for employee stock options and the 2004 Purchase Plan, and the value of options issued to non-employees for services rendered, was allocated to research and development and general and administrative expenses in the unaudited consolidated statements of operations for the three months ended March 31, 2016 and 2015 as follows (in thousands):

 

 

Three Months Ended

March 31,

 

 

2016

 

 

2015

 

Amortization of stock-based compensation:

 

 

 

 

 

 

 

Research and development

$

318

 

 

$

817

 

General and administrative

 

525

 

 

 

604

 

 

$

843

 

 

$

1,421

 

 
Weighted-Average Fair Value Valuation Assumptions

The fair value of employee stock options and employee purchase rights under the 2004 Purchase Plan was estimated using the following weighted-average assumptions for the three months ended March 31, 2016 and 2015:

 

 

Three Months Ended

March 31,

 

 

2016

 

 

2015

 

Employee Stock Options:

 

 

 

 

 

 

 

Risk-free interest rate

 

1.64

%

 

 

1.70

%

Expected term (in years)

 

6.02

 

 

 

6.02

 

Dividend yield

 

—

 

 

 

—

 

Volatility

 

108

%

 

 

83

%

Weighted-average fair value of stock options granted

$

0.45

 

 

$

3.13

 

 

 

Three Months Ended

March 31,

 

 

2016

 

 

2015

 

Employee Stock Purchase Plan (ESPP):

 

 

 

 

 

 

 

Risk-free interest rate

 

0.56

%

 

 

0.38

%

Expected term (in years)

 

1.24

 

 

 

1.25

 

Dividend yield

 

—

 

 

 

—

 

Volatility

 

161

%

 

 

51

%

Weighted-average fair value of ESPP purchase rights

$

0.22

 

 

$

1.59

 

 
Stock Option Activity Under Equity Incentive Plan

The following table summarizes stock option activity under the Company’s equity incentive plans:

 

Options

 

Number of

Shares

 

 

Weighted-

Average

Exercise

Price

 

 

Weighted-

Average

Remaining

Contractual

Term

 

 

Aggregate

Intrinsic

Value

 

Outstanding at December 31, 2015

 

 

9,032,136

 

 

$

3.77

 

 

 

—

 

 

 

—

 

Granted

 

 

2,735,000

 

 

$

0.54

 

 

 

—

 

 

 

—

 

Exercised

 

 

—

 

 

$

-

 

 

 

—

 

 

 

—

 

Forfeitures

 

 

(206,043

)

 

$

3.78

 

 

 

—

 

 

 

—

 

Outstanding at March 31, 2016

 

 

11,561,093

 

 

$

3.01

 

 

 

6.53

 

 

$

—

 

Vested and expected to vest March 31, 2016

 

 

11,434,385

 

 

$

3.03

 

 

 

6.50

 

 

$

—

 

Exercisable at March 31, 2016

 

 

7,085,144

 

 

$

3.65

 

 

 

4.74

 

 

$

—