Patent war intensifies: Glenmark launches generic version of Merck’s Januvia

As reported by Rupali Mukherjee of Times of India, in a move which will transform the landscape of the Indian pharma industry, Glenmark has launched a cheaper generic version of pharma multinational Merck’s blockbuster anti-diabetes drug Januvia (Sitagliptin phosphate). The generic vs. innovator battle earlier restricted to anticancer and anti-retroviral meds has now entered uncharted territory; just when you thought things couldn’t get any murkier! 

Image from here

Numbers and market dynamics: 

Owing to obesity and lifestyle changes, India has acquired the dubious distinction of becoming world’s diabetic capital followed closely by China. Emerging markets like India offer huge untapped potential and opportunity for anti-diabetic drug launches. According to this IMS report, the market for non-insulin diabetes treatments has experienced strong growth over the last decade, averaging 9.5% over the past five years. 

Traditionally, therapies for Non-Insulin dependent diabetes was dominated by relatively old and off- patent drugs primarily comprising biguanides (metformin) and sulfonylureas. For majority of type II diabetics, since medications have to be taken daily to achieve glycemic control, drug resistance is a major challenge. Thus there is a therapeutic void which generates demand for novel anti-diabetic product classes. Dipeptidyl peptidase-4 inhibitors (DPP-4) or what is known as “gliptins” offered a new alternative in the treatment pathway. 

Among the DPP-4 inhibitors/gliptins, Merck’s Januvia (Sitagliptin) and Novartis’s Galvus (Vildagliptin) are India’s first patented oral anti-hyperglycemics. In India, Merck’s Januvia was launched in April 2008, few months before Novartis’s Galvus was launched in Sept 2008. Merck and Novartis also partnered with domestic pharma companies to take advantage of local sales force to increase market penetration. Novartis joined forces with domestic generic USV to promote Galvus. Under an India-specific agreement, Merck partnered with Sun Pharma to launch local brand Istamet .In addition Merck also continued to market Sitagliptin in India under the Januvia brand. Januvia is touted as the undisputed leader among the gliptins with the brand accounting for about 80% of worldwide sales for anti-diabetic monotherapy. In India the gliptins market share is estimated at about 500 crore! 

Patent status and launch of generic version by Glenmark 

A very cursory patent check (IPO) reveals that 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. Apart from this, Merck is pursuing two patent applications which specifically cover Janumet extended release (sitagliptin+metformin combo). 

According to the Times of India article, a Glenmark official confirmed the launch of generic version of sitagliptin and said “"Glenmark is a responsible company and has launched the products after due diligence and research. Like other branded generics, Glenmark's Zita & Zita-Met are also branded generics." Further according to the article, Glenmark states that its product is “non-infringing” on Merck’s drug. 

First of all, the question of infringement should be evaluated against patent claims and not against innovator’s products. Also, one wonders how one can be non-infringing to a product patent? 

Pricing scenario: 

Januvia and Janumet are once daily prescription pills. As per CIMS Asia, a strip of 7 tablets of Januvia (strengths 50mg and 100mg) is priced at Rs. 300. That works out to around Rs. 43/day. Merck has adopted tiered/differential pricing and launched Januvia in India at one fifth of its US price, less than a dollar a day. According to the TOI article, Glenmark has priced its generic version around 30% cheaper than Merck’s Januvia and the overall savings to the patient could be around 5000 Rs./year.Going by the some of the tremendously steep price reductions we have seen for some anti-cancer drugs recently, I would say that the price reduction offered here is modest.Also, as reported here, many experts assert that Metformin, a 50 year old drug still works best for diabetics and has the least side effects. With so many alternative efficacious and affordable therapeutic options available for diabetic patients; I wonder whether the “public interest” factor will feature in this case. 

Conclusion: 

Merck was upset with the generic launch and an official was quoted as saying “We are disappointed in Glenmark's decision to introduce products that directly infringe upon our intellectual property. We believe our patents for Januvia and Janumet are valid and enforceable and will vigorously defend them.” Coup de grâce for Big Pharma? Another patent war on the cards? Only time will tell.