The patent claimed that AZT had both prophylactic and treatment properties. The generic manufacturers attacked the patent on the grounds that there was no sound basis to predict that the drug had any prophylactic properties. The Court did not accept this argument, instead holding that the definition of "prophylaxis" includes "prevention of the development of signs and symptoms of the disease [AIDS] without necessarily eradicating the causal factor [HIV]". The generic drug manufacturers also sought to have the patent declared invalid on the grounds that the NIH researchers who did the human cell screening were not identified in the patent as co-inventors. Justice Binnie concluded that, to be considered a co-inventor, a person must have participated in the inventive concept and not merely its verification.