Pfizer illegally gamed the Canadian patent system to monopolize the market for Viagra and overcharge customers, a class action claims in British Columbia Supreme Court. Lead plaintiff Britton Low claims that the Supreme Court of Canada invalidated Pfizer’s patent on Viagra in November, citing shoddy Patent Act disclosures, after a legal dispute with generic drug maker Teva Pharmaceuticals. Teva wanted to bring a generic version of Viagra (sildenafil) to the Canadian market, but could not while the case wound its way through Federal Court and eventually up to the Canadian Supreme Court. Days after that ruling, Pfizer reduced the price of Viagra to the price for the generic version, Low claims. He claims that Pfizer tailored its original patent application to be ambiguous, though it knew that sildenafil was the effective ingredient. The application “failed to clearly set out what the invention was,” according to the complaint.