Net Loss per Share Attributable to Common Stockholders (Tables)
 6 Months Ended 12 Months Ended
Jun. 30, 2016
Dec. 31, 2015
Earnings Per Share [Abstract]    
Common Shares Excluded from the Calculation of Net Loss per Common Share Attributable to Common Stockholders

The following table sets forth the potential common shares excluded from the calculation of net loss per common share attributable to common stockholders because their inclusion would be anti-dilutive:

 

     June 30,  
     2016      2015  

Options to purchase common stock

      389,969         333,368   

Warrants to purchase common stock

      2,556,966         2,596,966   
  

 

 

     

 

 

  

Total

      2,946,935         2,930,334   
  

 

 

     

 

 

  

The following table sets forth the potential common shares excluded from the calculation of net loss per common share attributable to common stockholders because their inclusion would be anti-dilutive:

 

     December 31,  
     2015      2014  

Options to purchase common stock

      332,400         300,026   

Common stock underlying Series A and Series A-1 convertible preferred stock

      —          1,630,097   

Warrants to purchase common stock

      2,556,966         462   
  

 

 

     

 

 

  

Total

      2,889,366         1,930,585