Quarterly report pursuant to Section 13 or 15(d)

Stock Options and Warrants - Additional Information (Detail)

v3.19.1
Stock Options and Warrants - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Apr. 08, 2019
Apr. 05, 2019
Jan. 04, 2019
Apr. 16, 2019
Mar. 29, 2019
Feb. 28, 2019
May 31, 2018
Feb. 28, 2018
Feb. 28, 2019
Feb. 28, 2018
May 31, 2018
Mar. 20, 2019
Feb. 13, 2019
Feb. 01, 2019
Jul. 10, 2018
Jun. 15, 2018
Aug. 24, 2017
Mar. 31, 2016
Feb. 28, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Vesting period   5 years     5 years                            
Exercise price of warrants, per share             $ 1.00       $ 1.00                
Common Stock issued           304,679,081 216,881,790   304,679,081   216,881,790                
Compensation expense                 $ 2,891,548 $ 1,096,226                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number     1,145,834                                
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Description and Terms     150,000                                
Subsequent event                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares       150,000                              
Warrants to purchase common shares, shares   785,700                   3,895,200              
Exercise price of warrants, per share   $ 0.50                   $ 0.50              
Common Stock issued   8,730,000                                  
Managing Director                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number                             100,000        
Placement Agent                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Warrants to purchase common shares, shares                         965,563     133,600      
Term of warrants                               5 years      
Exercise price of warrants, per share           $ 0.50     $ 0.50       $ 0.50     $ 0.55      
Consultant                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Warrants to purchase common shares, shares           300,000     300,000                    
Term of warrants           5 years     5 years                    
Exercise price of warrants, per share                           $ 0.56          
Warrants grant date fair value           $ 0.30     $ 0.30                    
Consultant | compensable warrant                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Warrants to purchase common shares, shares           500,000     500,000                    
Term of warrants           5 years     5 years                    
Exercise price of warrants, per share           $ 0.51     $ 0.51                    
Warrants grant date fair value           $ 0.28     $ 0.28                    
Investor                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Warrants to purchase common shares, shares           5,000,000     5,000,000                    
Term of warrants           5 years     5 years                    
Exercise price of warrants, per share           $ 0.30 $ 0.50   $ 0.30   $ 0.50                
Common Stock issued             3,295,000       3,295,000                
Proceeds from Issuance of Common Stock                     $ 1,600,000                
Private Equity Offering                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Warrants to purchase common shares, shares           23,487,585     23,487,585                    
Term of warrants           5 years     5 years                    
Exercise price of warrants, per share           $ 0.75     $ 0.75                    
Proceeds from Issuance of Common Stock                 $ 23,500,000                    
Private Equity Offering | Subsequent event                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Warrants to purchase common shares, shares                       1,000,000              
Private Equity Offering | Placement Agent                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Warrants to purchase common shares, shares           4,446,917     4,446,917                    
Term of warrants           5 years     5 years                    
Exercise price of warrants, per share           $ 0.50     $ 0.50                    
Subscription Agreements                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Warrants to purchase common shares, shares                               1,970,000      
Term of warrants                               5 years      
Exercise price of warrants, per share                               $ 0.75      
Convertible notes payable offering                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 5,460,000                    
Stock option granted, exerices price                 $ 0.30                    
Stock options grant date fair value                 $ 0.50                    
Term of warrants           5 years     5 years                    
Share Based Compensation Arrangement by Sharebased Payment Award Options Vested           $ 972,000     $ 972,000                    
Direct equity offering                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 5,364,240                    
Stock option granted, exerices price                 $ 0.50                    
Term of warrants           5 years     5 years                    
Direct equity offering | Placement Agent                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock options grant date fair value                 $ 0.50                    
Share Based Compensation Arrangement by Sharebased Payment Award Options Vested           $ 965,563     $ 965,563                    
Employee Stock Option One | Managing Director                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, exerices price                 $ 0.50                    
Stock options grant date fair value                 $ 0.27                    
2012 Equity Incentive Plan                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Compensation expense           1,400,000   $ 600,000 $ 2,900,000 1,100,000                  
Grant date fair value of options and warrants           700,000 $ 1,800,000   800,000 $ 1,300,000                  
Unrecognized compensation expense           $ 4,900,000     $ 4,900,000                    
Weighted average period over which unrecognized compensation expense is expected to be recognized                 2 years 6 months 29 days                    
2012 Equity Incentive Plan | Executive Management and Employees                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                     800,000                
2012 Equity Incentive Plan | Employee Stock Option One | Managing Director                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 38,904                    
Stock option granted, exerices price                 $ 0.47                    
Vesting period                 1 year                    
2012 Equity Incentive Plan | Employee Stock Option One | Managing Director | Tranche One                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option vested, Shares                 13,904                    
2012 Equity Incentive Plan | Employee Stock Option One | Managing Director | Tranche Two                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option vested, Shares                 25,000                    
2012 Equity Incentive Plan | Employee Stock Option One | Managing Director | Range One                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 680,822                    
Stock option granted, exerices price                 $ 0.49                    
2012 Equity Incentive Plan | Employee Stock Option One | Managing Director | Range Two                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 80,822                    
2012 Equity Incentive Plan | Employee Stock Option One | Executive Chairman                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock options, term                 10 years                    
2012 Equity Incentive Plan | Employee Stock Option One | Non Employee Directors [Member]                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 80,822                    
Stock option granted, exerices price                 $ 0.30                    
Stock options grant date fair value                 $ 0.31                    
2012 Equity Incentive Plan | Employee Stock Option One | Non Employee Directors [Member] | Minimum                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Annual increase stock option granted, shares                 75,000                    
2012 Equity Incentive Plan | Employee Stock Option One | Non Employee Directors [Member] | Maximum                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Annual increase stock option granted, shares                 100,000                    
2012 Equity Incentive Plan | Stock Options                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Shares available for future stock-based grants           164,144     164,144                    
2012 Equity Incentive Plan | Stock Options | Before Amendment                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Shares available for future issuance                                 7,000,000 5,000,000 3,000,000
2012 Equity Incentive Plan | Stock Options | After Amendment                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Shares available for future issuance                                 15,000,000 7,000,000 5,000,000
2012 Equity Incentive Plan | Stock Options | Managing Director                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 500,000                    
Stock option granted, exerices price                 $ 0.565                    
Stock options, term                 10 years                    
Stock options grant date fair value                 $ 0.30                    
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 875,000                    
Vesting period                 3 years                    
Stock options, term                 10 years                    
Stock options granted, exercise price, lower range limit                 $ 0.49                    
Stock options grant date fair value                 $ 0.31                    
2012 Equity Incentive Plan | Stock Options | Executive Chairman                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 950,000                    
Stock option granted, exerices price                 $ 0.49                    
Vesting period                 24 months                    
Stock options, term                 10 years                    
Stock options grant date fair value                 $ 0.41                    
2012 Equity Incentive Plan | Stock Options | Officer                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 1,000,000                    
Stock option granted, exerices price                 $ 0.565                    
Stock options, term                 10 years                    
Stock options grant date fair value                 $ 0.30                    
Stock option award vesting percentage                 50.00%                    
2012 Equity Incentive Plan | Stock Options | Officer | Subsequent event                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option award vesting percentage 50.00%                                    
2012 Equity Incentive Plan | Stock Options | Chief medical officer                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 350,000                    
Stock option granted, exerices price                 $ 0.551                    
Vesting period                 3 years                    
Stock options, term                 10 years                    
Stock options grant date fair value                 $ 0.30                    
2012 Equity Incentive Plan | Stock Options | Chief technology officer                                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                      
Stock option granted, Shares                 400,000                    
Stock option granted, exerices price                 $ 0.48                    
Vesting period                 3 years                    
Stock options, term                 10 years                    
Stock options grant date fair value                 $ 0.26