Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Tables)

v2.4.0.6
Stock Based Compensation (Tables)
 14 Months Ended
Mar. 31, 2013
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 ESPP, and the value of options issued to non-employees for services rendered, was allocated to research and development and general and administrative in the unaudited condensed consolidated statements of operations as follows (in thousands):

 

     Three Months Ended
March 31,		  
     2013      2012  

Research and development

    $ 534       $ 240   

General and administrative

      519         158   
  

 

 

     

 

 

  
   $ 1,053       $ 398   
  

 

 

     

 

 

  
Weighted-Average Fair Value Valuation Assumptions

The fair value of employee stock options and employee purchase rights under the Company’s ESPP was estimated using the following weighted-average assumptions for the three months ended March 31, 2013 and 2012:

 

     Three Months Ended
March 31,		  
     2013     2012  

Employee Stock Options:

     

Risk-free interest rate

      1.15 %      1.16 % 

Expected term (in years)

      6.02        6.08   

Dividend yield

        —     

Volatility

      101 %      105 % 

Weighted-average fair value of stock options granted

    $ 4.01      $ 2.52   

 

     Three Months Ended
March 31,		  
     2013     2012  

Employee Stock Purchase Plan (ESPP):

     

Risk-free interest rate

      0.20 %      0.20 % 

Expected term (in years)

      1.25        1.25   

Dividend yield

      —          —     

Volatility

      92 %      111 % 

Weighted-average fair value of stock options granted

    $ 2.44      $ 2.04   
Stock Option Activity Under Equity Incentive Plan

The following table summarizes stock option activity under the Company’s 2004 Equity Incentive Plan:

 

Options

    Number of
Shares		     Weighted-
Average
Exercise
Price		      Weighted-
Average
Remaining
Contractual
Term		      Aggregate
Intrinsic
Value		  

Outstanding at December 31, 2012

      5,098,972      $ 3.18         —           —     

Granted

      1,448,500      $ 5.05         —           —     

Exercised

      (25,423 )    $ 1.29         —           —     

Forfeitures

      (41,458 )    $ 7.69         —           —     
  

 

 

          

Outstanding at March 31, 2013

      6,480,591      $ 3.58         8.26       $ 10,700,852   
  

 

 

          

Vested and expected to vest March 31, 2013

      6,396,070      $ 3.56         8.24       $ 10,668,639   

Exercisable at March 31, 2013

      2,634,337      $ 2.15         7.10       $ 7,190,145