Annual report pursuant to Section 13 and 15(d)

Equity (Details Textual)

v3.8.0.1
Equity (Details Textual) - USD ($)
 1 Months Ended 12 Months Ended
Aug. 02, 2017
Jun. 06, 2017
Mar. 14, 2017
Oct. 04, 2016
Jun. 09, 2015
Feb. 11, 2015
Jan. 31, 2012
Dec. 21, 2015
Feb. 11, 2015
Dec. 31, 2013
Sep. 30, 2013
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Equity (Textual)                            
Net proceeds from issuance of shares                       $ 3,800,000    
Total unrecognized compensation expense                       $ 3,300,000    
Mr. Traversa [Member]                            
Equity (Textual)                            
Stock based compensation expense, Travesa options  

Pursuant to the agreement, all the outstanding vested options (which originally were to expire 90 days from termination date) as well as 68,200 unvested options granted prior to December 31, 2016, shall be exercisable until the end of the term of each option grant agreement.

                        
Fair value assumptions, expected dividend rate                       0.00%    
Total option expense                       $ 174,000    
Executive Chairman [Member]                            
Equity (Textual)                            
Warrant to purchase of common stock             64,746              
CEO [Member]                            
Equity (Textual)                            
Warrant to purchase of common stock             99,617              
Public offering [Member]                            
Equity (Textual)                            
Issuance of common stock, shares 21,500,000         4,444,444                
Proceeds from common stock issued $ 16,100,000     $ 8,000,000                    
Exercise price $ 1.05         $ 6.50     $ 6.50          
Warrants, vesting period 5 years                          
Fair value assumptions, expected discount rate           1.26%                
Fair value assumptions, expected term           4 years                
Fair value assumptions, expected volatility rate           72.00%                
Fair value assumptions, expected dividend rate           0.00%                
Warrant to purchase of common stock 18,275,000         3,333,333                
Offering price $ 0.75     $ 1.25   $ 4.50     $ 4.50          
Net proceeds from public offering $ 15,000,000         $ 18,500,000                
Fair value of warrants           $ 3,540,659     $ 3,500,000          
Warrants exercisable term                 4 years          
Underwritten offering common stock                 4,444,444          
Warrant [Member]                            
Equity (Textual)                            
Stock-based compensation expense                       $ 50,000 $ 100,000 $ 2,000,000
Exercise price $ 1.05                          
Common shares issued for cashless exercise of warrants                       1,736,277   1,532,124
Additional common stock issued for exercise of options and warrants                         23,212 224,153
Proceeds from stock options and warrants exercised                         $ 18,105 $ 173,620
Number of stock option/restricted shares canceled                       1,789,623    
Number of stock option/warrants granted                       18,496,575 130,000 3,333,333
Fair value of stock options and warrants                       $ 64,091    
Fair value assumptions, expected discount rate 1.83%                          
Fair value assumptions, expected term 5 years                          
Fair value assumptions, expected volatility rate 82.00%                          
Fair value assumptions, expected dividend rate                         0.00%  
Warrant to purchase of common stock 18,275,000   57,212                 9,364 183,718 2,013,360
Share Price $ 0.75                          
Fair value of warrants $ 4,900,000                          
Warrants exercisable term 5 years                          
Underwritten offering common stock 21,500,000                          
Common Stock [Member]                            
Equity (Textual)                            
Issuance of common stock, shares                       2,672,973    
Offering costs                       $ 200,000    
Common shares issued for cashless exercise of warrants                       4,234 125,892 1,736,277
Investor [Member]                            
Equity (Textual)                            
Proceeds from common stock issued         $ 5,000,000                  
Sale of stock, shares         1,923,078                  
Net proceeds from sale of stock         $ 4,480,000                  
Offering price         $ 2.60                  
Memorial Sloan Kettering Cancer Center [Member]                            
Equity (Textual)                            
Sale of stock, shares               5,700,000       1,230.954    
Consultants [Member]                            
Equity (Textual)                            
Common shares for consulting services, value                       $ 99,056    
Common shares for consulting services, shares                       67,385    
Share Price                       $ 1.47    
Consultants [Member] | Warrant [Member]                            
Equity (Textual)                            
Fair value of warrants                         $ 116,000  
Maximum [Member] | Mr. Traversa [Member]                            
Equity (Textual)                            
Fair value assumptions, expected discount rate                       1.39%    
Fair value assumptions, expected term                       8 years 10 months 25 days    
Fair value assumptions, expected volatility rate                       79.81%    
Maximum [Member] | Warrant [Member]                            
Equity (Textual)                            
Exercise price                         $ 1.77  
Fair value assumptions, expected discount rate                         1.20%  
Fair value assumptions, expected term                         10 years  
Fair value assumptions, expected volatility rate                         84.84%  
Warrants exercisable term                         10 years  
Minimum [Member] | Mr. Traversa [Member]                            
Equity (Textual)                            
Fair value assumptions, expected discount rate                       0.97%    
Fair value assumptions, expected term                       3 months    
Fair value assumptions, expected volatility rate                       45.72%    
Minimum [Member] | Warrant [Member]                            
Equity (Textual)                            
Exercise price                         $ 0.98  
Fair value assumptions, expected discount rate                         1.13%  
Fair value assumptions, expected term                         5 years  
Fair value assumptions, expected volatility rate                         79.79%  
Warrants exercisable term                         5 years  
2013 Equity Incentive Plan [Member]                            
Equity (Textual)                            
Number of additional shares authorized                   1,000,000        
2013 Equity Incentive Plan [Member] | Employees, directors and consultants [Member]                            
Equity (Textual)                            
Number of stock option/warrants granted                     450,000      
Plan expiration date                     Sep. 09, 2023      
2013 Stock Plan [Member]                            
Equity (Textual)                            
Number of additional shares authorized                       17,750,000 12,750,000 9,250,000
2013 Stock Plan [Member] | Employees, directors and consultants [Member]                            
Equity (Textual)                            
Number of stock option/warrants granted                     2,750,000      
Plan expiration date                     Sep. 09, 2023      
Stock Options [Member]                            
Equity (Textual)                            
Number of stock option/restricted shares canceled                       3,329,794 266,485 576,000
Number of stock option/warrants granted                       2,597,500 2,225,000 1,554,499
Stock options, term                       10 years 10 years 10 years
Fair value of stock options and warrants                       $ 2,400,000 $ 3,100,000 $ 3,200,000
Fair value assumptions, expected term                       6 years 6 years 6 years
Fair value assumptions, expected dividend rate                       0.00% 0.00% 0.00%
Total option expense                       $ 3,100,000 $ 3,600,000 $ 3,400,000
Gross proceeds                         $ 18,105 $ 15,680
Warrants exercised, shares                         23,212 20,000
Stock Options [Member] | Maximum [Member]                            
Equity (Textual)                            
Exercise price                       $ 1.58 $ 2.25 $ 3.58
Stock options, vesting period                       4 years 10 years 4 years 2 months 1 day
Fair value assumptions, expected discount rate                       2.28% 1.97% 1.91%
Fair value assumptions, expected volatility rate                       82.37% 87.95% 94.89%
Stock Options [Member] | Minimum [Member]                            
Equity (Textual)                            
Exercise price                       $ 0.57 $ 0.95 $ 1.79
Stock options, vesting period                       1 year 4 years 4 years
Fair value assumptions, expected discount rate                       1.84% 1.28% 1.56%
Fair value assumptions, expected volatility rate                       80.83% 81.45% 85.01%
Restricted Stock [Member]                            
Equity (Textual)                            
Issuance of common stock, shares                         21,000  
Stock-based compensation expense                       $ 200,000 $ 600,000 $ 3,400,000
Number of shares yet to issue of restricted stock, vested                       281,301    
Restricted stock granted, shares                         60,700  
Restricted Stock [Member] | Consultants [Member]                            
Equity (Textual)                            
Number of shares of restricted stock, vested                       26,000    
Common shares for consulting services, value                       $ 65,813    
Common shares for consulting services, shares                       59,393 250,700 479,651
Restricted stock granted value                         $ 400,000 $ 2,300,000
Restricted stock granted, shares                         60,700 329,651
Description of restricted stock                        

Of the 250,700 restricted share awards granted in 2016, 60,700 shares vested at the date of grant, 150,000 shares vest over a six-month period and 40,000 shares vest over 2 years.

Of the 479,651 restricted share awards granted in 2015, 329,651 shares vested at the date of grant and 150,000 shares vest over a six-month period.
Restricted Stock [Member] | Employees [Member]                            
Equity (Textual)                            
Number of stock option/restricted shares canceled                           126,265
Number of common stock options, granted                           152,499
Restricted stock granted value                           $ 800,000