Pfizer blockbuster to face competition
pharmafile | October 27, 2003 | News story | |
Pfizer's blockbuster hypertension and angina treatment Norvasc could face competition from a related drug following a US court ruling.
A ruling by the US District Court in New Jersey cleared Indian generics company Dr Reddy Laboratories to market a variant of Norvasc (amlodipine besylate) The drug, known as Istin in the UK, is the biggest selling hypertension drug in the world, with global sales of $3.6 billion in 2001 and second only to Lipitor in Pfizer's portfolio of blockbusters.
The court ruled that Dr Reddy product, amlodipine maleate which Pfizer itself had discovered was sufficiently different from Norvasc not to be covered by the US company patent, which expires in 2007.
Christine Hollidge, Senior Cardiovascular Analyst at Datamonitor, says: "It's potentially a huge blow to Norvasc, but at this stage it difficult to tell what will happen. It really depends on whether Dr Reddy can convince the FDA it is different enough. If they can do that, they will need data to show physicians it works as well as Norvasc."
Pfizer says it will appeal against what it called "a novel interpretation" of the US patent extension laws, and believes the matter must be reviewed in higher courts.
Meanwhile, Dr Reddy says it now plans to launch its product in August 2003 once it obtains final regulatory clearance and Pfizer paediatric exclusivity expires.
Even if the new product reached the market, Christine Hollidge says Pfizer has "arguably the strongest marketing in the industry" and will use its formidable salesforce to defend the drug's market share.
The forthcoming patent expiries of Merck enalapril (Innovace/Vasotec) and AstraZeneca lisinopril (Zestril) are two more significant milestones in hypertension treatment, one of the most competitive markets in the industry.
