Sun Pharmaceuticals has won a key patent of Eli Lilly’s block buster cancer medicine Gemzar (gemcitabine injection) in the US market. This will allow Sun Pharma to sell its generic version of the medicine in the US market from November 2010.

A district court in Michigan announced its decision in favor of Sun Pharmaceuticals on Monday. The decision will cancel a patent on gemcitabine injection which was set to expire in 2013.

Now, the company would easily manufacture a low-cost version of the same medicine in the world’s largest drug market.

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