In this case Teva Pharmaceutical Industries Ltd challenged the validity of Pfizer Pharmaceuticals Inc’s patent for the drug Viagra. Teva stated that Pfizer had not met the disclosure requirements set out in the Canadian Patent Act. The main issue on appeal was whether Pfizer had failed to properly disclose its invention when it obtained the patent for Viagra. The Supreme Court of Canada ruled that if a party attempted to “game” the system by obscuring the invention, they risked losing their exclusive rights to the invention.