Glaxo, Pfizer’s patent claims turned down

NEW DELHI: Indian authorities have rejected the patent applications of GlaxoSmithkline’s anti-diabetic drug Avandia and Pfizer’s cholesterol

lowering drug Caduet, allowing other companies to sell generic versions of these drugs. The applications were rejected as they did not measure up to the criteria of being new as well as being more useful than existing compounds. The application for Avandia (rosiglitazone) was refused because it failed to show any “enhanced efficacy over the existing compound”, while that for Caduet was rejected as the patent office did not find any “inventive step”. A patent grant would have ensured that no other company could make them without the consent of the patent-holder for the next two decades. The Delhi Patent Office accepted the objections raised by Ahmedabad-based Torrent Pharmaceuticals while rejecting a patent for Caduet, a combination of Pfizer’s two existing drugs Norvasc (amlodipine besylate) and Lipitor (atorvastatin calcium). The law allows interested parties to raise objections on patent applications. In the case of rosiglitazone, which is marketed as Avandia by GSK, the Patent Office said the company could not establish that the compound is “better in terms of efficacy with respect to its parent compound”. Several domestic companies, such as Dr Reddy’s Laboratories, Torrent Pharma and Sun Pharma, manufacture generic versions of rosiglitazone in India. Both the applications were turned down under a crucial section in the patent law, which says that mere modifications of existing substances cannot be granted patent, unless they establish significantly enhanced efficacy. “Both the applications lacked merit to overcome Section 3(d) of the Indian patent law, and hence, rejected. Combination (Caduet) application is unlikely to be granted patent in India, unless it shows unexpected results or synergy,” said Mumbai-based patent lawyer Varun Chhonkar. According to some estimates, global market for Caduet is around $589 million, of wkhich $120 million is from markets outside the US.