NEW YORK - CombinatoRx Inc. shares fell 46 percent after US regulators rejected an application for the experimental painkiller Exalgo.
The shares dropped 75 cents to 88 cents in Nasdaq Stock Market composite trading. The stock’s decline was the biggest since Jan. 26.
The application for the once-a-day tablet is not sufficient for approval, the Food and Drug Administration told CombinatoRx and its partner, Neuromed Pharmaceuticals Inc., the companies said in a statement.
Exalgo is the most advanced compound in the pipeline for Cambridge, Mass.-based CombinatoRx. It is buying closely held Neuromed, based in Vancouver, in an all-stock deal, in order to get more control of Exalgo.
The drug is designed to be the first extended-release version of hydromorphone in the United States since Purdue Pharma LP was forced to pull Palladone from the US market in 2005 because of overdose risks with alcohol.
