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Indian Court Sides with Merck in Patent Dispute

Posted 23 March 2015 | By Michael Mezher 

Indian Court Sides with Merck in Patent Dispute

A prominent court in India has issued an interim injunction, overturning a previous ruling, in favor of US drug maker Merck in a patent dispute with Glenmark Pharmaceuticals over an active ingredient used in two of Merck's diabetes medicines, Januvia and Janumet.


India’s patent system has been a source of frustration for western drug makers, which have argued for intellectual property (IP) reform in the country. While there have been several high-profile cases of India’s patent office rejecting western companies’ patent applications, some companies have found recourse through the country’s court system.

The patent at the root of this case is described in PCT/US2002/021349, which was filed by Merck in 2002 for the molecule sitagliptin and its pharmaceutically acceptable salts. Merck also applied for a patent (IN 209816) on the molecule in India in 2004, which was granted in 2007. Merck said its patent application was not opposed in India, and that it launched its products at an 80% discount compared to its US price.

The Dispute

In 2012, Glenmark received a patent in the US for the process of preparing R-sitagliptin and its pharmaceutically acceptable salts. Merck claimed that Glenmark infringed on its patent as Glenmark’s “product sitagliptin phosphate monohydrate cannot be prepared without manufacturing … the Sitagliptin molecule.” Merck also points out that Glenmark knew of its patent on sitagliptin, as Glenmark’s patent application references some of Merck’s related US patents.

In 2013, Merck filed for an injunction against Glenmark, alleging that two of the company’s products, Zita and Zitamet, infringed on Merck’s patent for sitagliptin.

In the initial hearing, Glenmark argued that Merck did not have patent protection for the phosphoric acid salt of sitagliptin in India, as Merck had abandoned a separate patent application for that form of the molecule. Merck countered this assertion by saying its patent includes the phosphoric acid salt form, and said it abandoned its efforts to patent the phosphate salt of sitagliptin separately out of concern it would not meet the patent office’s standard for therapeutic efficacy. The judge in that hearing dismissed Merck’s request for an interim injunction against Glenmark.

Merck appealed the dismissal, moving the case to a review by the division bench of the Delhi High Court. The bench took note of the fact that the free base of sitagliptin cannot be administered by itself, and “must be transformed into a salt before it can be administrated to patients.”

The two companies disagreed as to whether sitagliptin phosphate monohydrate is disclosed by Merck’s patent claim for pharmaceutically acceptable salts of sitagliptin. The bench found it would not be able to rule on this distinction, but found that Merck “established a prima facie case of infringement.” The case will now move back to the single judge for a hearing on 10 April 2015.

For now, the bench has set aside the single judge’s ruling, granting Merck’s request for an injunction until a final hearing can take place. The injunction prevents Glenmark from distributing the products found to be infringing on Merck’s patent, though stock of its product that has already been put on the market can continue to be sold.


Delhi High Court Decision


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