Winston Churchill’s October 1939 comment on the actions of Russia, “a riddle wrapped in a mystery inside an enigma”, was borrowed by US Court of Appeals for the Federal Circuit judge Alan Lourie to describe the patent resolution procedures of the act that governs biosimilars, the Biologics Price Competition and Innovation Act (BPCIA), in the 2015 case Amgen v Sandoz. The process to “unravel the riddle, solve the mystery, and comprehend the enigma” of the BPCIA is continuing, he said.