Pfizer loses Norvasc patent fight in Canada

On Thursday, Pharma giant Pfizer said it will appeal the Canadian Federal Court's decision to declare invalid a patent covering amlodipine besylate--the active ingredient in its hypertension drug Norvasc. Meanwhile, patent challenger Ratiopharm said its version of Norvasc, ratio-AMLODIPINE, will be available "imminently."

The generics maker was the first to go up against Pfizer in 2004 and won in 2006. That ruling was overturned in appeal, prompting Ratiopharm to sue to invalidate the patent. "We are extremely pleased at the decision by the Federal Court" Jean-Guy Goulet, CEO of Ratiopharm Canada, said in a statement. "This decision opens the amlodipine patent to generic manufacturers in Canada, the last major jurisdiction where the patent was held."

The decision could be a huge boost for Ratiopharm, which announced earlier this year that it would lay off 600 employees as it seeks to cut operating costs by $100 million. According to Ratiopharm, there are over 7.8 million prescriptions handed out for Pfizer's Norvasc per year, making amlodipine besylate the top selling medication in its class and Canada's second highest selling drug.

Pfizer is still battling several other patent challenges brought by other generics manufacturers in Canada. "Pfizer remains committed to protecting its intellectual property rights and to ensuring the long-term viability of its research and development programs," the company said in a statement.

- here's the Pfizer release
- read the Ratiopharm release