FDA Panel OKs QnexaFebruary 23rd, 2012 by MorganDowney Leave a reply »
Yesterday, the Endocrinologic and Metabolic Drugs Advisory Committee voted overwhelmingly, 20-2, in favor of approval of Vivus Inc.’s anti-obesity drug, Qnexa. It was one heck of a surprise.
The morning session included presentations by the company and the FDA staff on the effectiveness of Qnexa and, especially, the safety profile. The safety issues involved the issue of whether additional birth defects, particularly oral clefts, would result from wider administration of topiramate and whether phentermine contained a risk for cardiovascular events. The panel members were clearly wrestling with understanding the data. The company presented a very comprehensive Risk Evaluation and Management System (REMS) plan to reduce exposure to the drug by women of child-bearing potential. During the discussion, committee members and the FDA expressed concern that the REMS program might be too restrictive. They observed that if access were too limited, patients could do what they are doing now – use the two drugs in the generic forms off-label for obesity treatment.
Considering the cardiovascular risks, they were concerned about the relatively weak, but nevertheless present, sign of increased heart beats per minute and what that meant. This indicated a cardiovascular outcomes trial (like the SCOUT study for Meridia). The issue was whether the study would be done prior to approval or post approval. The key comments were made by Dr. Sanjay Kaul, usually a hawk on the obesity drugs, who opined that having the trial conducted post-approval would not be unreasonable. The effectiveness of the drug, about a 10% weight loss over a year, was the tipping point.
During the public witness part of the meeting, I testified, along with Ted Kyle for the Obesity Society, Denise Bruner for the American Society of Bariatric Physicians, Chris Gallagher for the American Society for Metabolic and Bariatric Surgery and Joe Naglowski for the Obesity Action Coalition. Ever since Qnexa was turned down in July 2010, we had been encouraging each other to testify and hold up the case for recognition of obesity as a disease and requiring additional tolls to fill the ‘treatment gap’ between lifestyle changes and bariatric surgery.
We huddled together as the votes were cast. The discussion among the panel members all day was of the ‘one the one hand on the other hand’ type. We expected a close vote. So, we nearly fell over at the 20-2 vote in favor of approval. Of course, the FDA has the final word and it does not have to follow the recommendations of the panel. Nevertheless, it seems more likely than not that the FDA will approve.
At the end of day, I felt that the long shadow that the phen-fen debacle has cast over the FDA might be lifting and that the panel may have achieved a higher recognition of the enormous implications of our ever growing obesity epidemic.
Arena Pharmaceuticals and Orexigen Therapeutics are still in the game with their drugs. While this positive vote, on the one hand may be good news for them, it may also set the effectiveness bar at a height their drugs cannot meet. Time will tell.