There seems to be no respite from legal battles for big pharma in India. Following the recently concluded Novartis Glivec case, a fresh legal battle has broken out between Merck Sharp & Dohme (MSD) and India's Glenmark Pharmaceuticals. MSD has filed a patent suit in India's Delhi High Court against the Mumbai-based generic player, alleging a violation of its patent for blockbuster anti-diabetes drugs Januvia and Janumet.

MSD's 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 medicines Zita and Zita Met and aims to grab a share of $600 million (Rs 3000 crore) Indian anti-diabetic market. Last month, Intendis, Intraserv and Bayer HealthCare also filed suits against Glenmark seeking to prevent it from commercializing its abbreviated new drug application (ANDA) prior to the expiration of US Patents. MSD's Januvia and Janumet enjoy patent protection of 20 years in India, starting on 2008. The drugs currently cost around 80 cents (Rs 40) per tablet and have turnover of $60 million (Rs 300 crore) in 2011. However, under the Drugs and Cosmetics Act of India, a company can apply for approval of a generic version of the patented drug four years after its launch.

An intersting development is this sseemingly David versus Goliath story is the fact news reports suggest that Sun Pharma has also joined the fray. In 2011, Sun Pharma had entered into an agreement with MSD for marketing, promoting and distributing MSD's diabetes products, including Januvia and Januvet. Sun Pharma would market these products under a different brand name.

An MSD spokesperson, while speaking about the issue, said that, "We are disappointed with Glenmark's decision to introduce products that directly infringe upon our intellectual property rights (IPR). We believe our patents for Januvia and Janumet are valid and enforceable and will vigorously defend those."