Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Details)

v3.3.0.814
Stock-Based Compensation (Details)
12 Months Ended
Jul. 31, 2015
USD ($)
$ / shares
shares
Jul. 01, 2015
shares
May. 18, 2015
Jan. 02, 2015
shares
Jul. 18, 2014
shares
Apr. 15, 2013
shares
Jul. 31, 2015
USD ($)
$ / shares
shares
Jul. 31, 2014
USD ($)
$ / shares
shares
Jul. 31, 2013
USD ($)
$ / shares
shares
May. 31, 2011
shares
Stock-based compensation                    
Exercise price, low end of the range (in dollars per share) | $ / shares             $ 3.60      
Exercise price, high end of the range (in dollars per share) | $ / shares             $ 16.10      
Expected volatility, minimum (as a percent)             86.02% 83.62% 80.32%  
Expected volatility, maximum (as a percent)             117.50% 93.27% 97.85%  
Risk-free interest rate, minimum (as a percent)             0.36% 0.10% 0.31%  
Risk-free interest rate, maximum (as a percent)             2.13% 2.78% 1.97%  
Expected forfeiture rate (as a percent)             0.00% 0.00% 0.00%  
Stock-based compensation expense recognized | $             $ 2,548,000 $ 1,816,000 $ 452,000  
Option Shares Outstanding                    
Balance at the end of the period (in shares) 1,148,764           1,148,764      
Aggregate Intrinsic Value                    
Reverse stock split ratio     0.05              
Minimum                    
Stock-based compensation                    
Expected term             1 year 7 months 6 days 1 year 3 years  
Maximum                    
Stock-based compensation                    
Expected term             6 years 6 months 10 years 10 years  
Research and development expense.                    
Stock-based compensation                    
Stock-based compensation expense recognized | $             $ 946,000 $ 666,000 $ 41,000  
General and administrative expenses.                    
Stock-based compensation                    
Stock-based compensation expense recognized | $             $ 1,346,000 $ 1,150,000 $ 411,000  
Stock Options                    
Stock-based compensation                    
Options granted to purchase shares             608,501 451,000 150,750  
Option Shares Outstanding                    
Balance at the beginning of the period (in shares)             588,045 257,500 158,750  
Granted (in shares)             608,501 451,000 150,750  
Exercised (in shares)             (308) (89,999) (38,325)  
Forfeited/Cancelled/Expired (in shares)             (47,474) (30,456) (13,675)  
Balance at the end of the period (in shares) 1,148,764           1,148,764 588,045 257,500  
Exercisable (in shares) 616,511           616,511      
Weighted-Average Exercise Price                    
Balance at the beginning of the period (in dollars per share) | $ / shares             $ 11.20 $ 4.60 $ 4.80  
Granted (in dollars per share) | $ / shares             7.45 13.20 4.40  
Exercised (in dollars per share) | $ / shares             5.60 4.20 3.60  
Forfeited/Cancelled/Expired (in dollars per share) | $ / shares             12.29 5.20 6.60  
Balance at the end of the period (in dollars per share) | $ / shares $ 9.20           9.20 $ 11.20 $ 4.60  
Exercisable (in dollars per share) | $ / shares $ 9.81           $ 9.81      
Aggregate Intrinsic Value                    
Balance at the beginning of the period (in dollars) | $             $ 844,000 $ 372,000 $ 24,000  
Granted (in dollars) | $             1,000 1,000 232,000  
Exercised (in dollars) | $             1,000 846,000 52,000  
Forfeited/Cancelled/Expired (in dollars) | $             46,000 65,000 9,000  
Balance at the end of the period (in dollars) | $ $ 216,000           216,000 $ 844,000 372,000  
Exercisable (in dollars) | $ $ 206,000           206,000      
Employees                    
Stock-based compensation                    
Term of stock options               10 years    
Exercise price, low end of the range (in dollars per share) | $ / shares               $ 6.20    
Exercise price, high end of the range (in dollars per share) | $ / shares               $ 16.100    
Employees | Minimum                    
Stock-based compensation                    
Vesting period               2 years    
Employees | Maximum                    
Stock-based compensation                    
Vesting period               3 years    
Board of Directors | Minimum                    
Stock-based compensation                    
Term of stock options               1 year    
Board of Directors | Maximum                    
Stock-based compensation                    
Term of stock options               10 years    
Consultants                    
Stock-based compensation                    
Exercise price, low end of the range (in dollars per share) | $ / shares               $ 5.20    
Exercise price, high end of the range (in dollars per share) | $ / shares               $ 16.100    
Non-employees | Research and development expense.                    
Stock-based compensation                    
Stock-based compensation expense recognized | $             58,000 $ 118,000 11,000  
Non-employees | General and administrative expenses.                    
Stock-based compensation                    
Stock-based compensation expense recognized | $             $ 198,000 $ 119,000 $ 289,000  
2011 Plan                    
Stock-based compensation                    
Number of shares authorized   3,500,000     1,250,000 450,000       260,000
Number of additional shares authorized 1,879,722     370,278 800,000 190,000        
Maximum percentage increase in number of share authorized, approved by shareholders         3.00%          
Maximum increase in number of shares authorized         500,000          
Maximum shares granted per fiscal year per individual   500,000                
2011 Plan | Minimum                    
Stock-based compensation                    
Purchase price of incentive stock options as a percentage of its fair value             100.00%      
Provisional percentage of outstanding stock owned by stockholders             10.00%      
Exercise price as a percentage of fair value of common stock for stockholders who own more than 10% of outstanding stock             110.00%      
2011 Plan | Maximum                    
Stock-based compensation                    
Term of stock options             10 years      
2011 Plan | Employees                    
Stock-based compensation                    
Term of stock options             10 years   10 years  
Options granted to purchase shares             491,001 90,500 34,250  
Exercise price, low end of the range (in dollars per share) | $ / shares             $ 5.60   $ 4.00  
Exercise price, high end of the range (in dollars per share) | $ / shares             $ 10.60   $ 8.40  
Option Shares Outstanding                    
Granted (in shares)             491,001 90,500 34,250  
2011 Plan | Employees | Minimum                    
Stock-based compensation                    
Vesting period             1 year   2 years  
2011 Plan | Employees | Maximum                    
Stock-based compensation                    
Vesting period             3 years   3 years  
2011 Plan | Board of Directors                    
Stock-based compensation                    
Term of stock options             10 years   10 years  
Options granted to purchase shares             37,500 37,500 15,000  
Vesting period             1 year   1 year  
Exercise price (in dollars per share) | $ / shares             $ 7.60 $ 16.100 $ 5.00  
Option Shares Outstanding                    
Granted (in shares)             37,500 37,500 15,000  
2011 Plan | Consultants                    
Stock-based compensation                    
Term of stock options               10 years    
Options granted to purchase shares             80,000 38,000 101,500  
Vesting period               1 year    
Exercise price, low end of the range (in dollars per share) | $ / shares             $ 6.01   $ 3.60  
Exercise price, high end of the range (in dollars per share) | $ / shares             $ 7.80   $ 7.00  
Option Shares Outstanding                    
Granted (in shares)             80,000 38,000 101,500  
2011 Plan | Consultants | Minimum                    
Stock-based compensation                    
Term of stock options             1 year   3 years  
2011 Plan | Consultants | Maximum                    
Stock-based compensation                    
Term of stock options             3 years   10 years  
Outside 2011 Plan | Employees                    
Stock-based compensation                    
Options granted to purchase shares               260,000    
Option Shares Outstanding                    
Granted (in shares)               260,000    
Outside 2011 Plan | Consultants                    
Stock-based compensation                    
Options granted to purchase shares               25,000    
Option Shares Outstanding                    
Granted (in shares)               25,000