AstraZeneca sues Ranbaxy over Nexium

Nexium has sales of $ 4 bn a year.

AstraZeneca has filed a lawsuit against Indian major Ranbaxy Laboratories in the district court of New Jersey, US, alleging "wilful infringement" of its patent for esomeprazole magnesium, marketed as Nexium, which has sales of $4 billion a year.

The lawsuit is in response to Ranbaxy's "Abbreviated New Drug Application" (ANDA) for the generic version of the drug with the US Food and Drug Administration (USFDA).

Indicated for acidity and heartburn relief, the drug is protected by six patents which are to expire between 2014 and 2019. The lawsuit automatically bars the USFDA from approving Ranbaxy's application for 30 months, or until an adverse court decision.

This would be another Para IV filing for Ranbaxy, which is emerging as one of the most aggressive generic patent challengers. In the face of such generic threat, innovator pharmaceutical companies are beginning to protect their turf fiercely.

"AstraZeneca has full confidence in and will continue vigorously to defend and enforce its intellectual property rights protecting Nexium," stated an AstraZeneca release. A Ranbaxy spokesperson said, "This was anticipated and the company had factored in the risk."

He added that the company had 32 Para IV filings out of which 19 were potential "first-to-file," giving the company exclusive marketing rights for 80 days. Out of these 19, seven were in litigation.

AstraZeneca, the third biggest drug maker in Europe, has lately suffered some reverses with a few drug hopes flopping. Israel's Teva Pharmaceuticals unveiled plans in September to launch a generic version of schizophrenia medicine Seroquel, another key growth driver for AstraZeneca.

Ranbaxy has been in news on account of litigation over $12 billion drug, Atorvastatin, which is sold by patent holder Pfizer as Lipitor and is being contested across the world.