Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Additional Information (Detail)

v3.10.0.1
Commitments and Contingencies - Additional Information (Detail) - USD ($)
 12 Months Ended
May 31, 2018
May 31, 2017
May 31, 2016
Commitments and Contingencies [Line Items]      
Royalty on every net sales 2.00%    
Asset Purchase Agreement Aggregate Consideration Paying Period 10 years    
Payment to acquire other assets     $ 1,500,000
Prepaid execution fees for process validation and manufacturing activities $ 1,862,009 $ 4,138,041  
Development Milestone Payments      
Commitments and Contingencies [Line Items]      
Asset Purchase Agreement Aggregate Consideration Paying Period 10 years    
Minimum annual license maintenance fees $ 150,000    
Project Work Order | Termination of Any One Clinical Trial | Minimum      
Commitments and Contingencies [Line Items]      
Financial penalties 100,000    
Project Work Order | Termination of Any One Clinical Trial | Maximum      
Commitments and Contingencies [Line Items]      
Financial penalties 1,100,000    
Project Work Order | Termination of All Clinical Trials | Minimum      
Commitments and Contingencies [Line Items]      
Financial penalties 800,000    
Project Work Order | Termination of All Clinical Trials | Maximum      
Commitments and Contingencies [Line Items]      
Financial penalties 2,400,000    
Contract Manufacturing Companies      
Commitments and Contingencies [Line Items]      
Execution fees for process validation and manufacturing activities   $ 2,100,000  
Prepaid execution fees for process validation and manufacturing activities 700,000    
Contract Manufacturing Companies | Termination of Any One Clinical Trial | Maximum      
Commitments and Contingencies [Line Items]      
Financial penalties 3,200,000    
Biologic License Application with the FDA or non-U.S. equivalent regulatory body | Milestone Payments      
Commitments and Contingencies [Line Items]      
Potential future milestone and royalties payments 500,000    
First US new drug application approval by the FDA or other non-U.S. approval | Milestone Payments      
Commitments and Contingencies [Line Items]      
Potential future milestone and royalties payments $ 5,000,000    
Royalty on every net sales 5.00%    
FDA approval or approval by another non-U.S. equivalent regulatory body | Development Milestone Payments      
Commitments and Contingencies [Line Items]      
Potential future milestone and royalties payments $ 500,000    
Royalty on every net sales 7.50%