8 April 2013Asia

Merck fails to ban Indian diabetes generics

Merck is the latest multinational pharma company to suffer a setback in India, after failing to win an injunction against generic versions of two anti-diabetes drugs.

The US company sued Indian generic-maker Glenmark for patent infringement on April 1, days after it began selling versions of its branded drugs Januvia (sitagliptin) and Janumet (sitagliptin plus metformin).

Glenmark has priced its drugs, Zita and Zita Met, at about 20 to 30 percent cheaper than Januvia and Janumet, monthly dosages of which sell for 1,300 rupees ($24) and 1,900 rupees ($35), respectively. They have been on the Indian market since 2008.

At the Delhi High Court on April 5, Justice Rajiv Sahai Endlaw denied Merck an injunction ahead of a full trial, saying it failed to show that the molecule in its drugs produced different results to the one in Glenmark’s.

The judge noted that sitagliptin contains three main elements, only one of which (sitagliptin hydrochloride) Merck has patented in India. Glenmark is selling sitagliptin phosphate monohydrate, and has claimed about 10 other companies are making products incorporating that version in India.

Merck argued there was no difference between its patented molecule and sitagliptin phosphate. This was despite Merck patenting all sitagliptin elements in the US, while it withdrew two Indian patent applications for the other two (including sitagliptin phosphate).

Justice Endlaw said Merck failed to argue that sitagliptin phosphate was merely a new form of the original compound sitagliptin and does not enhance its efficacy.

“I am unable to find any pleading of the plaintiffs to the said effect,” adding that Merck had only argued that sitagliptin phosphate is the same as sitagliptin.

Although Merck had tried and failed to patent sitagliptin phosphate in India, the judge noted that these applications were “mis-adventures”. This was because they amounted to ‘evergreening’, a banned practice allegedly used to extend the life of patents.

Despite this, Justice Endlaw said Merck still should have explained why it tried to apply for sitagliptin phosphate, noting that the company may do this during the trial.

The judge’s decision was correct, said Deepak Vaid, a lawyer at Surana & Surana International Attorneys in Chennai.

“Being aware of the unsuccessful Indian application for a patent for the same product, Merck ought to have pre-empted the defence and should have presented its case to show that, in spite of combining phosphate with the patented sitagliptin, the efficacy level would be the same.”

Although the judge’s observations may appear to favour Merck by explaining why its arguments were flawed, Vaid said Glenmark could also use them to its advantage too – for example, focusing on Merck’s withdrawal of its Indian application for sitagliptin phosphate.

He added: “Though the observations in the interim order will certainly be referred to during the course of proceedings, it could still be anybody’s case depending on who is able to prove the efficacy or non-efficacy of sitagliptin phosphate over sitagliptin.”

The ruling, while only preliminary, may raise more concerns that Indian patent laws favour generic manufacturing. Earlier this month, India’s Supreme Court delivered a landmark ruling that rejected Novartis’s bid to patent an updated version of its leukaemia drug Glivec. In March, Bayer’s appeal against a compulsory licence, which allows Indian generic company Natco to sell a cheaper version of its cancer drug Nexavar, was dismissed.

Neither Merck nor Glenmark responded to requests for comment.