Hyderabad: The US Court of Appeals for the Federal Circuit has ruled that Dr Reddy’s Laboratories Ltd would infringe a patent of Sunovion Pharmaceuticals Inc. blockbuster drug Lunesta.

Setting aside an earlier ruling given by a New Jersey Court, the federal Circuit Court said the lower court has “erred" in granting summary judgement of non-infringement by Dr Reddy’s. Lunesta (eszopiclone) is the prescription brand to treat insomnia. According to Dainippon Sumitomo Pharma, Lunesta generated $136 million revenues in North America and Chinese markets in the April-June quarter of the current fiscal.

Sunovin is a wholly-owned subsidiary of Dainippon Sumitomo Pharma Co. Ltd (DSP). “In view of the foregoing, we conclude that the district court’s construction of the asserted claims was correct, but we also conclude that the court erred in granting summary judgement of non-infringement to Reddy’s. Therefore, because Reddy’s ANDA (Abbreviated New Drug Application) specification infringes claim 1 of Sunovion’s 673 patent as a matter of law, the judgement of the district court is reversed," the court said in its order.

Sunovion, formerly known as Sepracor Inc., filed its infringement suit in March 2009, targeting 10 generics makers including Dr Reddy’s that had filed ANDAs for their own versions of Lunesta.

In January, the New Jersey federal judge observed that Dr Reddy’s didn’t infringe the patent of the drug belonging to Sunovion, finding that the Indian drug maker’s proposed generic version of the sleep aid is chemically different.

Sunovion argued that the district court erred in concluding that Dr Reddy’s would not infringe by making and selling its product approved by the FDA.

According to the federal court judgement copy, Dr Reddy’s original ANDA specification, submitted to the FDA on 15 December 2008, requested regulatory approval for generic eszopiclone products with some specifications.

However, the regulator on 24 June 2010 communicated to the company about the deficiencies in its ANDA specification. Thereafter, on 26 April 2012, Dr Reddy’s submitted an amended ANDA to the FDA.