WASHINGTON — Interneuron Pharmaceuticals Inc.’s FDA advisory committee meeting for Redux dexfenfluramine combined elements of surprise, a long-running scientific dispute and potential conflict with previous FDA decisions to result in the bizarre outcome of the meeting, at which committee members voted both to recommend and not to recommend approval of the drug to treat obesity.

The chaos at the deliberations of the Endocrinologic and Metabolic Drugs Advisory Committee on Sept. 28, (see BioCentury Extra Sept. 28 and BioCentury Oct. 2) also can be attributed to the fact that the committee members were confronted by scientific data outside their area of expertise, for which the agency apparently did little to prepare them.

Try again Nov. 16

At the meeting, the panel voted 5-3 against recommending approval of Redux based on doubts about the safety of dexfenfluramine (DF) as a long-term treatment for obesity raised by expert witnesses citing their research in animals. However, after three members of the panel had departed the meeting, a rump group voted 3-2 in favor of DF, after FDA officials asked them to consider whether the drug was approvable on a risk-benefit basis.