Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2015
Accounting Policies [Abstract]  
Schedule of Property and Equipment

Depreciation expense is recognized using the straight-line method based upon estimated useful life as follows:

 

     Years

Lab equipment

    3

Computer equipment

    3

Furniture and fixtures

    5

Leasehold improvements

    Shorter of life of lease or

estimated useful life

Schedule of Common Stock Equivalents, Excluded from Computation of Diluted Net Loss per Share

The following common stock equivalents outstanding as of December 31, 2015, 2014 and 2013 were excluded from the computation of diluted net loss per share for the years ended December 31, 2015, 2014 and 2013, because they had an anti-dilutive impact:

 

     December 31,  
     2015      2014      2013  

Stock options to purchase common stock

      2,861,011         2,146,927         1,124,116   

Restricted common stock units

      40,953         54,604         —     

Redeemable convertible preferred stock (as converted to common stock)

      —           —           14,860,173   
  

 

 

     

 

 

     

 

 

  
     2,901,964         2,201,531         15,984,289