Sun wins US court ruling in Eli Lilly patent challenge

Clears way for low-cost cancer drug launch in 2010.

Sun Pharmaceuticals has succeeded in having a key patent of Eli Lilly's blockbuster cancer medicine, Gemzar, invalidated in the US market. This means the company will now be able to launch a low-cost version of the medicine in the world's largest drug market in November 2010.

A district court in Michigan on Monday ruled in favour of Sun by invalidating a patent on gemcitabine, the generic name for Gemzar, which was set to expire in 2013. The invalidated patent, termed by Lilly as method-of-use patent, was aimed at extending the patent protection on the drug by three years. Teva and Hospira are the two other generic companies that are involved in patent litigation with Lilly on gemcitabine.

Gemzar is Lilly’s fourth best-selling drug and had worldwide sales worth $ 721 million for the first six months of 2009.

Lilly is all set to challenge the court ruling at the federal level.

"We strongly disagree with the Court's ruling granting summary judgment in favour of the generic challenger," said Robert A Armitage, senior vice-president and general counsel for Lilly. A Lilly statement added, "We continue to believe that our Gemzar method-of-use patent is valid and will be upheld by the courts. We intend to pursue an appeal of this decision with the Court of Appeals for the Federal Circuit. It is also important to note that today's court decision does not allow for the immediate entry of generic gemcitabine in the US market. Gemzar's compound patent remains in force until November 2010.”

Sun Pharma officials declined to comment.

The litigation process was triggered after Sun filed an application for marketing approval for the drug with the US drug regulator, challenging the method-of-use patent. The company sought permission to market the drug after its basic patent expires in 2010.