CombinatoRx Incorporated announced that the U.S. Patent and Trademark Office has issued the Company U.S. Patent No. 6,569,853 covering one of its anti-cancer drug candidates, the first in a new class of therapeutics that arrest tumor cell division at multiple phases of the cell cycle, leading to tumor cell death.

Using its proprietary technology, CombinatoRx systematically searches and discovers novel combination drugs. The resulting product comprises two existing drugs which act in concert to exhibit activity in an indication where neither may have use individually. The issued patent, which protects the combination of two components in a pharmaceutical composition, demonstrates the Company's ability to secure strong IP exclusivity on its products.

"This patent demonstrates that we can secure pharmaceutical composition patents on combinations of drugs and it will provide robust commercial protection for our products going forward," commented CEO Alexis Borisy. "CombinatoRx is the first company to systematically search combinations of existing drugs to discover and develop novel combination products. This patent is an important step in the execution of our business model."

CombinatoRx has filed over 70 product and technology patents in the U.S. and internationally. The Company's patent estate covers 35 unique classes of combination products.