Annual report pursuant to Section 13 and 15(d)

Stock Based Compensation (Details)

v3.3.1.900
Stock Based Compensation (Details) - USD ($)
12 Months Ended
Jun. 26, 2015
May. 06, 2013
Jan. 10, 2012
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Aug. 31, 2015
Apr. 28, 2011
Total stock-based compensation       $ 394,748 $ 1,086,581      
Option Activity, Number of shares                
Balance, beginning of period       552,726 381,669      
Granted       523,390 177,484      
Forfeitures       (116,928) (6,427)      
Balance, end of period       959,188 552,726 381,669    
Vested or expected to vest       959,188        
Exercisable       604,167        
Option Activity, Weighted-average exercise price                
Beginning of period       $ 9.17 $ 7.78      
Granted       6.31 12.14      
Forfeitures       8.60 8.68      
End of period       7.68 $ 9.17 $ 7.78    
Vested or expected to vest       7.68        
Exercisable       $ 8.51        
Option Activity, Fair value of options granted                
Granted       $ 1,467,886 $ 389,538      
Option Activity, Weighted-average remaining contractual term (in years)                
Balance       7 years 6 months 4 days        
Vested or expected to vest       7 years 6 months 4 days        
Exercisable       7 years 18 days        
Aggregate intrinsic value       $ 0        
Fair value of options vested in period       $ 700,000 $ 1,300,000 $ 600,000    
Per share weighted average fair value of options granted       $ 2.80 $ 2.24 $ 5.60    
Fair value assumptions                
Expected term of options (in years)           P6Y    
Expected stock price volatility       70.00% 70.00% 70.00%    
Expected annual dividend yield       0.00% 0.00% 0.00%    
Unrecognized compensation expense                
2016       $ 273,913        
2017       262,426        
2018       246,094        
2019       118,457        
Total unrecognized compensation expense       900,890        
Research and development expense                
Total stock-based compensation       67,021 $ 201,653      
General and administrative                
Total stock-based compensation       $ 327,727 $ 884,928      
Minimum                
Fair value assumptions                
Risk-free interest rate       1.64% 0.85% 0.85%    
Expected term of options (in years)       P5Y P5Y      
Maximum                
Fair value assumptions                
Risk-free interest rate       1.97% 1.97% 1.90%    
Expected term of options (in years)       P6Y3M P6Y3M      
2011 stock incentive plan                
Number of shares authorized for issuance   704,428           178,571
Increase in number of shares reserved for issuance   418,714 107,143          
Common stock remaining for future issuance (in shares) 0              
2011 stock incentive plan | Stock Options                
Options term (in years)       10 years        
2011 stock incentive plan | Minimum | Stock Options                
Vesting period       3 years        
2011 stock incentive plan | Maximum | Stock Options                
Vesting period       4 years        
2015 Omnibus Plan [Member]                
Number of shares authorized for issuance             890,815  
Common stock remaining for future issuance (in shares)       696,736        
Annual share reserve increase (as a percent) 3.00%