PX-3 is an indazole-based synthetic cannabinoid (also known as APP-CHMINACA). It is a potent agonist of the CB1 receptor with a binding affinity of Ki = 47.6 nM and was originally invented by Pfizer in 2009 as an analgesic drug.
The acronym ‘APP’ means the structure elements of ‘amino’,’ phenyl’ and ‘propanone’. EMCDDA published three associated compounds, PX-1 (5F-APP-PICA, SRF-30), PX-2 (5F-APP-PINACA, FU-PX) and APP-FUBINACA, in late 2014.