US-based Pfizer and its subsidiary Wyeth have sued Ranbaxy Laboratories in a US court claiming that the Daiichi Sankyo-owned drugmaker infringed on Wyeth’s patent coverage of the drug, Rapamune.
The drug is an immunosuppressant used to prevent organ rejection following kidney transplant for patients above 13 years of age. Rapamune (Sirolimus with strength -1 mg and 2 mg) tablet got approval from the US Food and Drug Administration in 2000. For the 12 months ended February 2010, Rapamune had garnered revenues worth $210 million in the US market, according to the IMS Health database. Pfizer and Wyeth also filed a patent infringement case against the US-based generic company, Watson Pharmaceuticals, for the same drug. The concerned patent is scheduled to expire on July 7, 2013.
Pfizer and Wyeth have filed their complaint against Ranbaxy and Watson at District Court of Delaware. “This is a civil action for the infringement of US patent No. 899. This action relates to ANDA (Abbreviated New Drug Approval) filed by Watson Florida and Ranbaxy Ltd with the USFDA for approval to market the generic versions of Pfizer’s Rapamune, drug product for the prophylaxis of organ rejection in patients aged 13 years or older receiving renal transplants,” said Pfizer in its complaint. The patent 899 deals with methods of inhibiting transplant rejection in mammals using Rapamycin and derivatives.
Ranbaxy was earlier engaged in a fierce and protracted patent battle with Pfizer over the blockbuster drug, Lipitor, in over 40 countries, and over Caduet. While Lipitor was world’s most prescribed cholesterol lowering drug, Caduet, combiles the active ingredient of Lipitor and Norvasc and treats high blood pressure and cholesterol.
In June 2008, Pfizer and Ranbaxy reached an out of court settlement on Lipitor. Ranbaxy was given the licence to sell the generic versions of Lipitor and Caduet in the US effective November 30, 2011, and on other dates in seven other markets.