Annual report pursuant to Section 13 and 15(d)

Equity (Details Textual)

v3.3.1.900
Equity (Details Textual) - USD ($)
 1 Months Ended 12 Months Ended
Jun. 09, 2015
Feb. 11, 2015
Jul. 10, 2014
Dec. 31, 2014
Jun. 30, 2014
Mar. 24, 2014
Jan. 31, 2014
Dec. 27, 2013
Sep. 30, 2013
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Equity (Textual)                        
Fair value assumptions, risk free interest rate [1]                   1.06% 1.10%  
Fair value assumptions, expected volatility rate [2]                   87.00% 71.00%  
Fair value assumptions, expected term                   2 years 3 years  
Fair value assumptions, expected dividend rate [3]                    
Proceeds from the exercise of options                   $ 15,680 $ 275,153 $ 13,053
Expense related to common stock granted                   3,400,000 2,400,000 300,000
Unrecognized compensation expense       $ 10,200,000           7,200,000 $ 10,200,000  
Gross proceeds from public offering         $ 12,500,000         15,100,000    
Net proceeds from public offering                   $ 14,700,000    
Price per share         $ 7.50         $ 2.52    
Common stock, par value       $ 0.001 $ 0.001         $ 0.001 $ 0.001  
Common stock issued, shares         1,670,000         5,626,119    
Proceeds from common stock issued                   $ 37,637,959 $ 15,435,305 2,883,257
Underwriting discount               $ 2,900,000        
Underwriting agreement description              
Investors agreed to purchase (i) an aggregate of 554,310 shares (the “Shares”) of common stock at $6.00 per share and (ii) five-year warrants to purchase an aggregate of 138,577 shares of common stock at an exercise price of $9.00 per share. The Company received $3.3 million in gross proceeds from the sale of securities.
        
Registration statement description          
This Registration Statement contained two prospectuses: (i) a base prospectus which covers the offering, issuance and sale by the Company of up to $200 million of its common stock, preferred stock, warrants and/or units; and (ii) a sales agreement prospectus covering the offering, issuance and sale by us of up to a maximum aggregate offering price of $75,000,000 of its common stock that may be issued and sold under a sales agreement (the “ Sales Agreement ” ) with MLV & Co. LLC ( “ MLV ” ) dated March 24, 2014.
            
Maximum offering price           75,000,000            
Aggregate offering amount of securities sold to investors           The Company will pay MLV in cash, upon the sale of common stock pursuant to the Sales Agreement, an amount equal to 3.0% of the gross proceeds from the sale of common stock. On April 28, 2014, the Company issued 500 shares and received net proceeds of $6,000 under the Sales Agreement with MLV.            
Proceeds from the sale of common stock, net of offering costs                   $ 37,637,959 15,435,305 $ 2,883,257
Fair value of warrants                     $ 2,100,000  
Investor [Member]                        
Equity (Textual)                        
Warrants issued to purchase common stock, shares                     137,952 138,577
Price per share $ 2.60                      
Proceeds from common stock issued $ 5,000,000                      
Proceeds from the sale of common stock, net of offering costs 5,000,000                      
Net proceeds from sale of stock $ 4,480,000                      
Shares purchased by investors 1,923,078                      
Consultant [Member]                        
Equity (Textual)                        
Fair value assumptions, expected term                     10 years  
Warrants issued to purchase common stock, shares                     285,000  
Consultant [Member] | Minimum [Member]                        
Equity (Textual)                        
Exercise price of warrants       5.55             $ 5.55  
Consultant [Member] | Maximum [Member]                        
Equity (Textual)                        
Exercise price of warrants       11.66             11.66  
2013 Stock Plan [Member]                        
Equity (Textual)                        
Number of additional shares authorized                   10,750,000    
2013 Stock Plan [Member] | Employees, directors and consultants [Member]                        
Equity (Textual)                        
Number of stock option granted                 2,750,000      
Award expiration date                 Sep. 09, 2023      
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 granted                 450,000      
Award expiration date                 Sep. 09, 2023      
Placement agent [Member]                        
Equity (Textual)                        
Exercise price of warrants                   $ 9    
Common stock issued, shares                       69,289
Placement agent cash fees             $ 400,000          
Placement agent attorney fees             40,000          
Net proceeds from sale of stock             3,300,000          
Net proceeds from issuance of services             2,900,000          
Warrant [Member]                        
Equity (Textual)                        
Fair value of warrants determined utilizing the Black-Scholes option pricing model             $ 600,000          
Exercise price of warrants       $ 9.00             $ 9.00  
Fair value assumptions, risk free interest rate             1.64%          
Fair value assumptions, expected volatility rate             88.00%         91.56%
Fair value assumptions, expected term             5 years       5 years 5 years
Fair value assumptions, expected dividend rate             0.00%       0.00% 0.00%
Expense related to common stock granted                   $ 200,000 $ 100,000 $ 200,000
Unrecognized compensation expense       $ 1,500,000             $ 1,500,000 $ 200,000
Price per share       $ 6.00             $ 6.00  
Common stock issued, shares       551,810               122,000
Warrants/ Common stock granted       137,952                
Warrants exercised by warrant holders                   2,013,360 2,501,993 2,403,429
Warrants to purchase common stock vested, shares                       72,000
Warrant to purchase common stock vested, value                       $ 200,000
Warrants to purchase common stock expected to vest, shares                       50,000
Warrants to purchase common stock expected to vest, value                       $ 200,000
Term of warrants             5 years          
Warrant [Member] | Minimum [Member]                        
Equity (Textual)                        
Exercise price of warrants                       $ 3.60
Fair value assumptions, expected volatility rate                     82.47%  
Fair value assumptions, expected discount rate                   1.56% 1.56% 1.36%
Term of warrants                       7 years
Warrant [Member] | Maximum [Member]                        
Equity (Textual)                        
Exercise price of warrants                       $ 6.70
Fair value assumptions, expected volatility rate                     87.76%  
Fair value assumptions, expected discount rate                   1.91% 1.66% 1.55%
Term of warrants                       10 years
Common Stock [Member]                        
Equity (Textual)                        
Common stock issued, shares                   1,736,277 2,336,658 2,336,988
Proceeds from common stock issued                   $ 200,000 $ 200,000 $ 3,500,000
Common Stock [Member] | Placement agent [Member]                        
Equity (Textual)                        
Fair value of warrants determined utilizing the Black-Scholes option pricing model             $ 300,000 $ 400,000        
Exercise price of warrants             $ 9.00          
Fair value assumptions, risk free interest rate             1.64% 0.07%        
Fair value assumptions, expected volatility rate             88.00% 84.06%        
Fair value assumptions, expected term             5 years 5 years        
Fair value assumptions, expected dividend rate             0.00% 0.00%        
Common stock issued, shares             68,976          
Restricted Stock [Member]                        
Equity (Textual)                        
Number of shares of restricted stock, granted                   344,784    
Expense related to common stock granted                   $ 3,400,000 $ 3,700,000 $ 200,000
Restricted Stock [Member] | Employees, directors and consultants [Member]                        
Equity (Textual)                        
Number of shares of restricted stock, granted                   152,499 633,041 312,500
Restricted stock granted value                   $ 800,000 $ 4,900,000 $ 700,000
Restricted stock granted not been issued                     202,497  
Number of stock option cancelled                   126,265 50,000  
Description restricted stock                     Of the total shares of restricted stock granted, 20,000 shares vest 3 months from the grant date, 30,374 shares vest 1 year from the grant date, 30,000 shares have a vesting period of 2 years, 202,497 shares have a vesting period of 4 years and 350,000 shares vest at the date of grant. 80,000 shares of restricted stock vest 1 year from the grant date, 100,000 shares have a vesting period of 24 months. The remaining restricted shares granted are performance based and vest over time.
Restricted Stock [Member] | Consultant [Member]                        
Equity (Textual)                        
Number of shares of restricted stock, granted                   479,651    
Restricted stock granted value                   $ 2,300,000    
Restricted stock granted not been issued                   329,651    
Description restricted stock                   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.    
Public Offering [Member]                        
Equity (Textual)                        
Exercise price of warrants   $ 6.50                    
Fair value assumptions, expected volatility rate   72.00%                    
Fair value assumptions, expected term   4 years                    
Fair value assumptions, expected dividend rate   0.00%                    
Fair value assumptions, expected discount rate   1.26%                    
Warrants issued to purchase common stock, shares   3,333,333                    
Number of additional stock option granted     157,123                  
Proceeds from the exercise of options     $ 1,200,000                  
Gross proceeds from public offering   $ 20,000,000 13,700,000                  
Net proceeds from public offering   $ 18,500,000 $ 12,600,000   $ 11,500,000              
Price per share $ 2.60 $ 4.50 $ 7.50                  
Common stock issued, shares   4,444,444 1,827,123                  
Underwriting discount     $ 12,600,000   $ 900,000              
Underwriting agreement description   In addition, the Company granted the underwriters a 30-day option to purchase up to an additional 666,666 shares of common stock and warrants to purchase 499,999 shares of common stock solely to cover over-allotments, if any. The underwriter did not exercise the over-allotment option.     Under the terms of the underwriting agreement, the Company also granted the underwriters a 30-day option to purchase up to an additional 250,000 shares of common stock to cover over-allotments, if any, at the offering price.              
Warrants/ Common stock granted   666,666                    
Other offering expenses         $ 100,000              
Auditor fees         $ 100,000              
Fair value of warrants   $ 3,500,000                    
Warrant One [Member]                        
Equity (Textual)                        
Common shares issued for cashless exercise of warrants                   1,532,124 2,162,181 235,158
Additional common stock issued for exercise of options and warrants                   224,153 484,877 2,118,480
Proceeds from stock options and warrants exercised                   $ 173,620 $ 435,147 $ 3,480,448
Stock Option Plan [Member]                        
Equity (Textual)                        
Fair value of warrants determined utilizing the Black-Scholes option pricing model                      
Fair value assumptions, expected term                   6 years 6 years 6 years
Fair value assumptions, expected dividend rate                   0.00% 0.00% 0.00%
Number of stock option granted                   1,554,499 1,338,100 787,450
Number of stock option cancelled                   576,000   1,115,550
Share-based compensation term                   10 years 10 years 10 years
Share-based Compensation vesting period                     4 years 4 years
Fair value of stock option                   $ 3,200,000 $ 8,700,000 $ 3,700,000
Stock option exercise prices                   $ 0.78 $ 0.95 $ 0.78
Proceeds from the exercise of options                   $ 15,680 $ 275,153 $ 13,053
Number of option exercised                   20,000 310,400 16,650
Warrants/ Common stock granted                       787,450
Stock Option Plan [Member] | Minimum [Member]                        
Equity (Textual)                        
Exercise price of warrants                       $ 3.60
Fair value assumptions, expected volatility rate                   85.01% 82.47% 83.32%
Fair value assumptions, expected discount rate                   1.69% 1.77% 1.36%
Share-based Compensation vesting period                   1 year    
Stock option exercise prices                   $ 1.79 $ 0.78  
Stock Option Plan [Member] | Maximum [Member]                        
Equity (Textual)                        
Exercise price of warrants                       $ 6.70
Fair value assumptions, expected volatility rate                   94.89% 87.76% 98.45%
Fair value assumptions, expected discount rate                   1.91% 2.07% 1.55%
Share-based Compensation vesting period                   4 years 2 months 1 day    
Stock option exercise prices                   $ 3.58 $ 11.95  
[1] The risk-free interest rate was determined by management using the Treasury Bill rate as of the respective measurement date.
[2] As of December 31, 2015, the volatility was estimated using the historical volatilities of the Company's common stock traded in NYSE MKT market. As of December 31, 2014, the volatility was estimated using the historical volatilities of comparable companies in the same industry and region.
[3] Management determined the dividend yield to be 0% based upon its expectation that it will not pay dividends for the foreseeable future.