After the news that Novartis failed to secure an Indian patent for Glivec, the patenting woes of Western pharma in India seem to continue as Merck are denied interim relief in a patent case against Glenmark.

The decision came within days of Merck’s subsidiary, MSD India, dragging the domestic company to court over the sale of its blockbuster Januvia. Recently, Glenmark launched a more affordable version of Januvia in the domestic market, triggering a patent war, and heightening tensions between MNCs and domestic generic companies, already embroiled in several patent disputes.

The judge for the hearing has been Justice Rajiv Sahai Endlaw. He refused to grant any interim relief and immediately dismissed the interim application of the multinational pharma major. The plea said that the Indian company must be restrained from manufacturing and selling the anti-diabetes medicines because the salts used in the drugs are not of generic nature.

High Court responded to the application by keeping the main petition of the US firm pending for filing of evidence and other succeeding legal proceedings till July 16.

This article is an attempt to analyze and dissect this elaborated judgment of Delhi High Court to


The molecule having International Non-Proprietary name of “SITAGLIPTIN” was invented by the plaintiff Merck who has patents for the same in 102 countries of the world including India. International application for patent was filed on 5th July, 2002 with the priority date of 6th July, 2001 and the application in India was filed on 6th January, 2004.The patent in India was granted on 6th September, 2007 and is valid for 20 years from 6th July, 2001. Plaintiffs‟ commercial product sold in India under the brand name “JANUVIA” and “JANUMET”.

SITAGLIPTIN was approved for sale in United States of America (USA) in October, 2006 and in the Indian market on 28th March, 2008.  Plaintiffs in public interest have priced JANUVIA as a daily pill at about Rs.43/- a pill, it is roughly 1/5th of its price in the USA – this is probably the first case of differential pricing in India and which price was arrived at after surveys, of the same being within the reach of the people in need of the said medicine.

The defendant itself obtained US patent dated 18th December, 2012 for its process for preparation of SITAGLIPTIN and in the said patent has acknowledged the plaintiffs‟ corresponding US patent for SITAGLIPTIN. that the defendant had started distributing SITAGLIPTIN and SITAGLIPTIN PLUS METFORMIN under the brand names ZITA and ZITA-MET in the form of sample packs



Plaintiff(Merck’s Arguments):

Merck’s counsel argued that the packaging of the plaintiff’s product JANUMET which describes its pharmaceutical composition as “Sitagliptin Phosphate & Metformin Hydrochloride and the packaging of the defendant‟s product which describes its pharmaceutical composition as “Sitagliptin Phosphate Monohydrate Tablets” ,the package insert information reveals that the pharmaceutical composition of plaintiff’s product is similar to composition of Glenmark’s product Zita and hence the infringement is obvious.

Merck’s counsels also emphasized that “there is no price difference in the product of the plaintiffs and defendant thus it cannot be said that the product of the defendant is considerably cheaper than that of the plaintiffs to allay the influence of Novartis Supreme court decision.

Defendant ‘s (Glenmark’s arguments):

Glenmark’s counsel counter arugued that the plaintiffs are  guilty of suppression and are not entitled to the grant of discretionary relief of interim injunction on the ground that  the plaintiff –Merck had failed to disclose that the patent application ( referring to the 5948/DELNP/2005) for the product for which injunction was sought was not only declined and also abandoned.

Further ,analogy was drawn to the Roche vs. Cipla (2012) judgement in which the plaintiff sought to injunct the product version for which the patent application was rejected. On the basis of Roche vs. Cipla judgement it was argued that when the role of the variant (in this particular case Sitagliptin phosphate) outweighs the patented claim (Sitagliptin only), there can be no infringement.

Thus ,The plaintiff , US firm .Merck said it had invented ‘Sitagliptin’ salt, used in the anti-diabetes drugs and has patent over the molecule.    However, the  Defendant ,Indian firm,Glenmark  said it has used ‘Sitagliptin Phosphate’ in its anti-diabetes drugs, Zita and Zita-Met and the US firm has no patent right over this salt and hence no infringement has occurred.

2) separate patents for Sitagliptin and salt form of Sitagliptin: WHY IT WAS DONE?


Senior counsel for the defendant alleged that plaintiffs are guilty of suppression and had failed to disclose that the patent application (probably referring to the 5948/DELNP/2005) for the product for which injunction was sought was not only declined and also abandoned.

Glenmark’s counsel elaborated that its product for which injunction is sought  comprises of three parts “S”, “PD” and “DC” (referring to Sitagliptin, dihydrogenphosphate salt and crystalline form), and  Merck has separate patents for each of these parts in USA.

Glenmark’s counsel further argued  that Merck holds the patent in India only for the first part  i.e. for Stiagliptin and separate patents for the other two parts i.e. phosphate salt and crystalline form were denied and affirmatively abandoned. Hence from the compilation of documents handed over during the hearing, it was shown that the plaintiffs‟ patent is for Sitagliptin Hydrochloride only and not for Sitagliptin Phosphate

Further ,Glenmark’s counsel also argued that Merck in its patent application (5948/DELNP/2005) had described that the combination of S and PD i.e. (Sitagliptin and phosphate salt) as a new discovery not covered by existing Sitagliptin patent. In light of this Merck cannot allege that defendants combination of “Sitagliptin and phosphate salt” infringes Merck’s patent. Glenmark also stated that “plaintiffs patent is for Sitagliptin Hydrochloride only and not for Sitagliptin Phosphate.” Placing reliance on Paras 139 and 156 of the Supreme Court Novartis judgement, it was contended that “coverage in a patent cannot be permitted to go much beyond the disclosure made by the patentee”

It was also argued that if Sitagliptin phosphate and Sitagliptin weren’t distinct products, then Merck wouldn’t have applied for separate patents for each of those in US and India.

It was also contended that there is no concept of a basic patent in India. Defendants referred to  Section 54 of the Act which permits addition to patents and  contended that the plaintiffs have not come to the Court with a case of Sitagliptin Phosphate being an improvement patent within the meaning of Section 3(d) and as per the documents suppressed by it seems that palintiff’s are trying to be making out the same to be a case under Section 54 of the Act.


Plaintiff’s counsel argued that that a distinction has to be carved out between a basic and an improved patent.It was argued that Sitagliptin was the invention and Sitagliptin phosphate was merely a derivative and therefore wasn’t eligible for patent protection under Section 3(d).The separate patent application for Sitagliptin phosphate filed by Merck was due to some misconception, which is why they affirmatively abandoned the same. It was also stated that, separate patent for Sitagliptin phosphate was applied for since the US has no Section 3(d) equivalent patent law.


The court held Merck had not disclosed that it had abandoned the patent for sitagliptin phosphate (currently being sold version) in India.  Glenmark argued that the patent for sitagliptin (original Januvia molecule) and sitagliptin phosphate (currently being sold) are different. However, Merck said sitagliptin and sitagliptin phosphate are covered by different patents in US and Europe.Merck was unable to explain its own admission of “new discovery” made in its sitagliptin phosphate application Glenmark   also pointed  out that several other companies are manufacturing sitagliptin phosphate API (active pharmaceutical ingredient) in India.

The  learned judge also noted that Merck has had made a separate patent application for Phosphate salt form of Sitagliptin, considering it to be a new invention worthy of a separate patent. Plaintiff (Merck) has not satisfactorily pleaded the circumstances for obtaining a separate patent application.

Justice Endlaw also elaborated that the defendant had also pointed out that there were at least 9-10 infringers marketing Sitagliptin phosphate. “Though, ordinarily infringement by others does not constitute a ground for denial of the relief of injunction against an infringer but it can be a consideration in the grant of interim injunction.” “I do not find the plaintiff (MSD) to have made out a case for grant of interim relief. The application is accordingly dismissed but with a direction to the defendant (Glenmark Pharmaceuticals) to diligently maintain accounts of the manufacturing/production and sales of the infringing products and to file the same before this court with advance copy to the counsel for the plaintiff,” Justice Rajiv Sahai Endlaw said in the interim order.


The Hight court Judgement is an elabotated and detailed judgement but I find it little strange. Judgement appears to be appropriate and correct in the first look but if one reads the Merck patent on StigplatinIN209816 clearly states “The compound as claimed in claim 1 (referring to markush structure of gliptins) selected from the group consisting of <structure of sitagliptin> or a pharmaceutically acceptable salt thereof.” On the face of it if sitagliptin was covered by the claim, then any salt form of it would also be covered. I fail to un