Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Common Stock Warrants - Additional Information (Detail)

v3.20.1
Common Stock - Common Stock Warrants - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended
May 30, 2019
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
Class of Warrant or Right [Line Items]        
Common stock, par value   $ 0.001   $ 0.001
Expected volatility   104.06% 93.72%  
Risk-free interest rate   1.51% 2.56%  
Expected term   6 years 7 days 6 years 7 days  
Number of warrants exercised   0 0  
New Warrant [Member]        
Class of Warrant or Right [Line Items]        
Fair value of warrants recognized into accumulated deficit   $ (3.9)    
Stock price   $ 4.23    
Expected volatility   97.16%    
Risk-free interest rate   2.06%    
Expected term   6 years    
Armistice [Member]        
Class of Warrant or Right [Line Items]        
Proceeds from aggregate warrant exercise $ 4.2      
Armistice [Member] | October 2018 Financing [Member]        
Class of Warrant or Right [Line Items]        
Warrants to purchase common stock 270,313      
Common stock, par value $ 0.001      
Exercise price per unit of warrant $ 3.1445      
Armistice [Member] | June 2018 Financing [Member]        
Class of Warrant or Right [Line Items]        
Warrants to purchase common stock 837,500      
Exercise price per unit of warrant $ 4.00      
Armistice [Member] | New Warrant [Member]        
Class of Warrant or Right [Line Items]        
Warrants to purchase common stock 1,200,000      
Exercise price per unit of warrant $ 4.50      
Warrants, exercise period 6 years