Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Stock-based Compensation Expense Recognized (Detail)

v3.19.1
Stock-based Compensation - Stock-based Compensation Expense Recognized (Detail) - USD ($)
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]    
Total Stock-based compensation $ 145,829 $ 118,324
Research and Development [Member]    
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]    
Total Stock-based compensation 36,303 8,856
General and Administrative [Member]    
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]    
Total Stock-based compensation $ 109,526 $ 109,468