Dec. 7, 2010 -- After back-to-back rejections of drugs targeting obesity in the last six months, an FDA advisory committee today voted 13-7 in favor of approving a new medication aimed at aiding people in losing weight and maintaining that weight loss.
The drug, made by Orexigen and to be marketed as Contrave if granted final approval by the FDA, will become one of the few drugs available for the treatment of obesity. The FDA’s decision is due by Jan. 31.
“Clinicians and patients need additional options,” said John Buse, MD, of the University of North Carolina School of Medicine, who addressed the Endocrinologic and Metabolic Drugs Advisory Committee on the drugmaker’s behalf. The risk-to-benefits ratio, he said, “falls clearly on the side of benefits.”
In general, the committee agreed with that statement. However, serious concerns about the drug’s impact on cardiovascular health were the subject of much of the day’s discussion. Supporting documents submitted by the manufacturer showed that the blood pressure of some patients taking Contrave in clinical trials went up as their weight went down.
“I am most distressed about this particular adverse effect,” said committee member Jules Hirsch, MD, of Rockefeller University in New York City. “There needs to be very, very careful attention if this drug is approved.”
To that end, the committee voted 11-8 to require Orexigen to study their drug’s impact on heart health following its approval. In July, they rejected an obesity drug application from drugmaker Vivus; two months later, they voted against Arena Pharmaceutical’s proposed obesity medication, lorcaserin. The FDA formally rejected both drugs in October.
Modest Weight Loss From Contrave
Contrave is a combination of two drugs, both of which have been on the market for about 25 years. Bupropion, commonly prescribed to treat depression and also approved to help people quit smoking, curbs the appetite, while naltrexone, approved to treat opioid and alcohol addictions, amplifies this effect.
That effect may not lead to dramatic weight loss, however. Most patients taking Contrave in clinical trials lost about 5% of their starting body weight.
“Even modest weight loss can have a profound effect on health,” said Caroline Apovian, MD, of the Boston University School of Medicine, who spoke on behalf of Orexigen.
Committee members, though they voted positively, did not do so very enthusiastically. While the company’s efficacy data met the FDA’s criteria, it did so “by the hair of [its] chinny chin chin,” said patient representative Melanie Coffin.
Sanjay Kaul, MD, of UCLA’s David Geffen School of Medicine, agreed. “It’s a charitable interpretation, but yes, they made it,” he said.
Many of the committee members also expressed concern that no data exist that give any clues about the drug’s safety or efficacy beyond the one-year mark, the cutoff point for the studies submitted by the manufacturer.
“It’s a long-term condition, and we need long-term data,” said Diana Zuckerman, PhD, of the National Center for Women and Families, who addressed the committee during the open public hearing.