Trio Of Anti-Obesity Drugs Pursuing Second Attempt At FDA Approval
February 25, 2012

Trio Of Anti-Obesity Drugs Pursuing Second Attempt At FDA Approval

The makers of three previously rejected weight loss drugs have resubmitted their products to the Food and Drug Administration (FDA) for approval, with each hoping to become the first new prescription anti-obesity drug to be approved in the U.S. in 13 years.

As previously reported here on, one of those three drugs, Qnexa, received approval from a panel of FDA advisors on Thursday by a 20-2 margin.

That verdict placed Qnexa, a combination of the appetite suppressant phentermine and the anti-seizure and migraine drug topiramate that is manufactured by Vivus, one step closer to reaching the market. According to the Associated Press (AP), "topiramate is believed to make patients feel more satiated."

When the medication was rejected previously, the FDA asked Vivus for additional clinical data on the drug's potential impact on major cardiovascular events and birth defects. Studies have also shown that topiramate use during pregnancy can increase the risk of birth defects, including oral clefts.

One question the advisory committee considered is whether or not Vivus should be required to conduct a large new clinical trial before the medicine receives final approval, in order to determine whether the drug can increase a person's risk of heart attack. Vivus is requesting permission to conduct the study after receiving approval, in the hopes of avoiding additional delays which could last several years.

"Many experts view the combination pill as the most promising of the new weight loss drugs, due to studies showing most patients lost nearly 10 percent of their weight -- the highest reduction reported with any recent diet pill," the AP wrote. A second ruling on the drug is expected by April 17, the news agency added.

The other two medications up for approval are Orexigen Therapeutics' Contrave, a combination of an antidepressant and an anti-smoking drug believed to curb appetite, and Arena Pharmaceutical's lorcaserin, which stimulates serotonin receptors in the brain in order to make people feel fuller.

The AP describes Contrave's results as "lackluster." Approximately 40% of those taking the medication losing 5% of their body weight -- barely allowing the medication to qualify as an effective weight loss pill under the FDA's minimum requirements, according to the wire service. There are also cardiovascular concerns surrounding Contrave, leading the FDA to order a 10,000-patient heart health study scheduled to be completed in two years' time.

"Lorcaserin has faced the most severe safety questions from FDA, which rejected the drug in 2010 after raising concerns about cancerous tumors seen in rats who received the drug," the AP said. "Early this year Arena submitted new information evaluating the link between its drug and cancer. The FDA is scheduled to make a new ruling on the drug by June 27."


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