In something of a reversal in fortunes for multinational pharma companies, Merck & Co this week won an injunction against the sale of generic versions of two of its diabetes drugs in India.
The company’s MSD unit successfully blocked Indian pharma company Aprica Pharmaceuticals from launching generics of Januvia (sitagliptin) and Janumet (sitagliptin plus metformin), according to a Reuters report.
A case against another drugmaker that has already launched generic copies of the two drugs – Glenmark Pharmaceuticals – is not due to come to court until next month.
In April the High Court in Delhi refused to impose an injunction on Glenmark’s sales of the products, which are sold as Zita and Zita Met, although it kept MSD’s petition for patent infringement open.
The MSD victory comes against a backdrop of defeats for Western pharmaceutical companies trying to defend their intellectual property in India.
Earlier this year Novartis failed in a bid to secure protection for its Glivec (imatinib) cancer drug in India’s Supreme Court, and there have also been knockbacks in recent months regarding Roche’s Pegasys (peginterferon alfa-2a), Merck & Co’s Singulair (montelukast), Gilead Sciences’ Viread (tenofovir), Pfizer’s Sutent (sunitinib) and Bayer’s Nexavar (sorafenib tosylate).
The patent infringement case against Glenmark centred on the salt form of sitagliptin used in Zita and Zita Met. MSD has a patent on sitagliptin in India but decided against pursuing a separate patent on the phosphate salt of the drug – even though these are patented separately in the US – as it believed India’s intellectual property (IP) laws rendered a separate filing redundant.
In essence, because the phosphate salt form was a derivative of sitagliptin it should have been ineligible for protection under section 3(d) of India’s patent regime. Glenmark however launched generics containing the phosphate salt and argues that as a result it does not infringe Merck’s IP in India.
While details of the Aprica judgment have not yet come to light, it is possible that its generics use the same form of sitagliptin in Januvia and Janumet, which might explain why the courts have blocked Aprica’s products whilst letting Glenmark’s remain on the market.
Merck has been selling Januvia on the Indian market since 2008, and also allows domestic drugmaker Sun Pharmaceutical to sell it under licence as Istavel. Januvia is the company’s top-selling product with sales of around $4.1bn last year, with Janumet adding another $1.6bn to the tally.