Quarterly report pursuant to Section 13 or 15(d)

Organization and Description of Business - Additional Information (Detail)

v3.20.1
Organization and Description of Business - Additional Information (Detail) - USD ($)
3 Months Ended
Dec. 18, 2019
Dec. 12, 2019
Jun. 12, 2015
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
Organization And Description Of Business [Line Items]            
Accumulated deficit       $ (219,692,871)   $ (212,114,385)
Net cash used in operating activities       $ (7,549,320) $ (7,324,726)  
Number of shares issued 2,565,000 3,715,000        
Public offering price, per unit $ 3.90         $ 2.70
Net proceeds received $ 10,000,000          
Gross Proceed   $ 13,000,000        
Combined Net Proceeds   $ 21,300,000        
Private Placement [Member]            
Organization And Description Of Business [Line Items]            
Number of shares issued     4,728,128      
Public offering price, per unit   $ 2.70        
Net proceeds received     $ 18,300,000      
Issuance of securities in private placement, Shares   1,111,111