Quarterly report pursuant to Section 13 or 15(d)

Stockholders' equity - Schedule of warrants or rights (Detail)

v3.22.4
Stockholders' equity - Schedule of warrants or rights (Detail) - $ / shares
 3 Months Ended
Dec. 31, 2022
Sep. 30, 2022
Outstanding, beginning of period 42,088,194 107,095
Pre-funded warrants exercised 2,171,628  
Outstanding, ending of period 39,916,566 42,088,194
Exercisable at December 31, 2022 39,916,566  
Exercise price of class of warrants or rights outstanding $ 0.49 $ 10.5
Pre-funded warrants exercised 0.0001  
Exercise price of class of warrants or rights outstanding 0.52 $ 0.49
Exercisable at December 31, 2022 $ 0.52  
Series 2 Warrants [Member]    
Series 2 Warrants issued September 15, 2022   29,809,471
Series 2 Warrants issued September 15, 2022   $ 0.66
Pre-funded warrants [Member]    
Pre-funded warrants issued   12,171,628
Pre-funded warrants issued   $ 0.0001