22 Dec 2009

On 11 December 2009, the U.S. Food and Drug Administration (FDA) announced approval of a generic version of Aricept (donepezil hydrochloride), one of the first prescription drugs to be marketed for the treatment of mild to moderate Alzheimer disease. The agency’s blessing went to Mutual Pharmaceuticals of Philadelphia, which plans to start marketing generic pills in a little under a year. The patent on Aricept, held by Eisai, expires 25 November 2010.

The new approval is for donepezil pills that dissolve on the tongue, a plus for seniors who have trouble swallowing. Another plus is that the arrival of a generic usually heralds a drop in the cost of the prescription drug. For AD patients who pay out of pocket or who have high prescription co-pays, this may be welcome news. How soon price reductions may be realized is not clear, however. According to data from the FDA, meaningful cost savings (approximately 50 percent) typically happen when two or more generics enter the fray. Teva, an Israeli purveyor of generic drugs, was tentatively given approval by the FDA for its generic donepezil in January 2008, but wound up in court when Eisai sued to prevent the company from marketing the drug until an extension on Eisai’s original patent had expired. Teva had asserted that the Eisai patent was unenforceable. Eisai won a court injunction in March 2008 (see related Wall Street Journal article). It is not clear if Teva plans to market its generic once Eisai’s patent expires.

Aricept accounted for one-third of Eisai’s total sales in 2009. In Japan the company has launched an oral jelly version of the drug also designed to circumvent the problem some patients have with swallowing. In the U.S. they have filed a New Drug Application with the FDA for an extended release version of the drug for the treatment of moderate to severe AD. The extended release tablets (23 mg) will be tested head-to-head against the regular 10 mg tablets in an upcoming clinical trial. Mutual Pharmaceuticals’ generic drug will come in the standard 5 and 10 mg doses.—Tom Fagan.