Forest Laboratories suffered a setback yesterday after the US Food and Drug Administration said it would not approve the company’s application to widen the indication for its Alzheimer’s disease medication, Namenda (memantine), to include treatment of the mild form of the condition. However, the firm said that the move would not impact its earnings per share guidance for the twelve months to March 2006, which remains at $2.30.

The firm said that the FDA had initially stated that a single study in patients with mild to moderate Alzheimer’s disease would be adequate to support an expended indication, and further acknowledged that a six-month, mild-to-moderate study which reached statistical significance at the required primary endpoints fitted the bill. Nevertheless, the company notes that the agency decided not to approve Namenda for mild Alzheimer's based on this single positive study in light of data from two other Namenda trials, which failed to reach statistical significance [[08/01/04b]], [[16/11/04e]].

Namenda was approved back in October 2003 for the treatment of moderate-to-severe Alzheimer’s disease - peak sales have been forecast in the region of $650 million dollars, which could have been further boosted by an expanded indication [[20/10/03b]]. Forest says it plans to meet with the FDA to further discuss the non-approvable letter.