The India Patent battle takes a new twist
With the recent rejection of Novartis? patent hitting the headlines India?s generic drug market is back in the news, this time Mumbai-based Glenmark Pharmaceuticals Ltd. is the target and Merck (MSD) is looking to sue over patent-infringement. Glenmark recently announced two anti-diabetic drugs, Zita and Zita Met, which have prematurely infringed on Merck?s Januvia and Janumet patents. As Glenmark is seeking to market its drugs at a 30% discount compared to Merck?s if the lawsuit finds in favour of Glenmark there will be a significant impact on Merck?s share of India?s $550 million anti-diabetic market.
What is the drug at the centre of the dispute?
Merck developed an oral hypoglycaemic, Sitagliptin (Sitagliptin Phosphate is marketed as Januvia), that was approved in 2006 as an inhibitor for dipeptidyl peptidase-4 (DPP-4). DDP-4 inhibitors prolong the effects of Incretin hormones, such as GLP-1, by preventing DDP-4 degradation of the hormone. This results in inhibition of Glucagon release which, in turn, increases secretion of Insulin. In combination this reduces high blood glucose levels which are associated with diabetes mellitus type II. This DDP-4 inhibitor can also be combined with another oral antihyperglycemic agent, such as metformin, to form Janumet that is more beneficial to the patient as it has fewer side effects.
What are the arguments?
According to moneycontrol.com the dispute again lies in Merck?s patents for the drugs. Merck has 2 patents related to Sitagliptin, the original form and Sitagliptin Hydrochloride. They claim that all other forms, including Januvia?s form Sitagliptin Phosphate, are covered under these patents and Glenmark has no authority to offer generic versions. Glenmark argue that Sitagliptin phosphate is not covered by the original patents as it is a different compound.
What is likely to happen?
What is interesting is that Merck filed a separate patent for Januvia but later abandoned it. I hypothesise that by not filing the “Januvia patent” Merck gives Glenmark some leverage in the dispute, and that this missing patent will be the deciding factor in the dispute. If Glenmark can prove that Merck understood that Januvia was different enough to warrant filing another patent then it is likely that India?s courts will find in favour of Glenmark.
– Jonathan Mackinnon