The Food and Drug Administration (FDA) began reviews this month on three new weight loss drugs. The first to be reviewed, Qnexa developed by Vivus Inc., which is a mixture of two existing drugs, an anticonvulsant (topiramate) and an amphetamine (phentermine). The drug performed well in trials with subjects losing 13 percent and 15 percent of their body weight. However, an FDA advisory committee voted 9-7 to reject Vivus’s application to approve Qnexa, citing concerns over side effects. This leads many to wonder if any of the three drugs will pass muster.

The next drug slated for review by the FDA, in October, is Contrave by Orexigen Therapeutics Inc.  Contrave is also a mixture of an anticonvulsant and an amphetamine but in different dosages. According to Mike Narachi, CEO or Orexigen, Contrave is a combination drug that “targets behavior and reward pathways in the brain.” It combines the antidepressant Wellbutrin (bupropion) with naltrexone, an opioid blocker used to treat alcoholism and opiate addiction. Contrave is designed to address the craving issue that many overeaters experience.

Contrave met all main goals in three different late-stage clinical trials, but also more than satisfied the effectiveness requirement of the Food and Drug Administration (FDA). About 50 percent of patients who took Contrave were shown to lose an average of 5 percent of their body weight over a one-year period. The company said that Contrave also calms food cravings, allowing patients to have better control over their eating.

During the trials, those patients who took Contrave experienced significantly greater weight loss than those who received a placebo. In addition, Contrave reduced other risk factors such as waist circumference, midsection fat and triglycerides, while it improved levels of “good” HDL cholesterol and lowered blood sugar levels in patients with diabetes.

The results of two of the trials showed that 48 percent and 56.3 percent of Contrave patients had weight loss of at 5 percent or more compared to only 16.4 percent and 17.1 percent for patients taking placebo. The mean weight loss of those taking Contrave was 17.6 pounds and 17.5 pounds (8.1 percent and 8.2 percent). The participants in the trials numbered 1,742 patients and 1,496 patients, respectively, and each trial lasted 56 weeks. Neither of the trials included diabetes patients. These findings surpassed FDA testing guidelines that require a minimum of one-third of patients to lose at least five percent of their body weight, while at least double the number patients must attain the 5 percent goal in comparison to patients taking a placebo.

The third trial, which included 505 type II diabetes patients, had results of 44.5 percent of Contrave patients losing at least 5 percent of their weight over a period of 56 weeks, compared to only 18.9 percent of those patients who received a placebo. In addition, the Contrave patients had a blood sugar reduction of 0.6 percent in comparison to only 0.1 percent for the placebo patients. The mean weight loss in the trial was 13.5 pounds (5.9 percent) in Contrave patients compared with 5.1 pounds (2.2 percent) for placebo patients.