Post Novartis Glivec case ruling competition between MNC pharmaceuticals & Indian generic companies gets fierce as US based Merck Sharp & Dohme (MSD), the third largest pharma company by revenues , has filed a patent infringement suit with Delhi High court against domestic generic company Glenmark  Pharmaceuticals. MSD move comes a week after Glenmark launched generic versions of a range of anti-diabetes products, which are sold by MSD under the brand names Januvia and Janumet. Glenmark has named its  generic medicines Zita and Zita Met and aims to grab a share of $600 million (Rs 3000 crore) in the Indian anti-diabetic market.

This article throws a light on the case and discusses what are the chances of Plantiff’s (MSD’s)victory in this battle between Innovator and generic company.


India has continued to be the country with highest number of people having  diabetic population globally and it is expected to be 69.9 Million by 2025. Such a huge number  of diabetic populations will lead to growth in diabetes medicines such as insulin which will be  fuelled by increased access to health insurance, greater patient spending power and more  aggressive treatment practice.

Januvia-A BlockBuster Drug by Merck&Co

Type II diabetes has been  dominated by old and off-patent drugs in the early stages of treatment, but there always remained a significant growth opportunity for new patented products because of the progressive nature of the disease, and considerable remaining unmet need.

DPP-IVs (dipeptidyl peptidase -4 (DPP-4)) is an enzyme that breaks down GLP-1 (glucagon-like polypeptide 1), a hormone that has a profound effect on stimulating the release of insulin from the pancreas. As a result, GLP-1 has a very short life in the blood , offered a new alternative in the treatment pathway.

The first DPP-IV inhibitor to enter the market was Sitagliptin marketed as sitagliptin phosphate under the trade name  Januvia) introduced in 2006 in the US by Merck, is an oral antihyperglycemic (antidiabetic drug) of the dipeptidyl peptidase-4 (DPP-4) inhibitor class. This enzyme-inhibiting drug is used either alone or in combination with other oral antihyperglycemic agents (such as metformin or a thiazolidinedione) for treatment of diabetes mellitus type 2.

Today, Januvia & its combination version Janumet (combined with metformin) dominates sales of DPP-IV products in developed markets, with the brand accounting for about 80% of worldwide sales for single-compound products. Januvia ,a blockbuster drug   by Merck & Co. ,is a real success story.

Patent status and launch of generic version by Glenmark 

Merck’s Januvia is protected by two patents in India viz. IN209816 and IN219148. IN209816 is a product patent which specifically covers Sitagliptin. IN219148 claims process intermediates used in the manufacture of Sitagliptin. Apart from this, Merck had filed a patent application 5948/DELNP/2005 covering the phosphate salt form and enantiomers of Sitagliptin, but this patent application was abandoned following a pre-grant opposition taking the grounds of Section 3 (d) of Indian Patent Act.


Glenmark has priced its diabetes drug around 30% cheaper than Merck’s Januvia, and the savings to patients could be nearly Rs 5,000 a year. Merck’s diabetes therapies Januvia and Janumet, launched in the Indian market in 2008, are part of the ‘gliptin’ family. The drugs together are nearly Rs 200-crore brands, making them one of the fastest growing medicines, and are ranked No. 2 in the oral diabetics market (according to IMS data). 


US-based Merck’s subsidiary in India has dragged  Glenmark to court seeking  an injunction over the marketing of blockbuster diabetes drug, Januvia (sitagliptin) and seeking a  stop on the sale of a more affordable version of diabetes drug, Januvia. Sun Pharma, which has a marketing agreement with MSD India for Januvia, also joined hands against Glenmark. A hearing in the case has already started, but a ruling was deferred on 02ND April.

As per the reports it is said that the Glenmark’s generic version is still available in the market since there is no order as yet on restraining its marketing yet. Glenmark’s official has maintained that its product is “non-infringing” on Merck’s drug, and its drugs, Zita & Zita-Met are branded generics.


When applying to enter the market with a generic form of a reference product, the generic company files an Abbreviated New Drug Application (ANDA) and certifies against patents listed in the Orange Book.   The certification states that either (a) FDA should approve of its generic version after the date the last patent expires (a “Paragraph 3” filing) or (b) that its generic product does not infringe on the listed patents or that those patents are not enforceable (a “Paragraph 4” filing actually called a Paragraph IV filing.1

If the generic company files an ANDA with a Paragraph IV certification, then the branded company is notified.   After the notice, the branded company has 45 days to file a patent infringement action against the generic company.   After the suit has been filed, the FDA cannot approve of the application until the generic company successfully defends the suit or until 30 months, whichever comes first.

Infringement is evaluated against patent claims and not against innovator’s products and in this situation it is likely that Merck’s will have  a say in this case  because  patents for Januvia and Janumet are valid and enforceable and Merck will vigorously defend them.


Though it was widely expected that MSD would pursue the legal option on Januvia, Sun Pharma’s joining the case is an interesting development, considering there are few instances where a domestic generic company has taken on another.