Weight Loss Drug Empatic Meets Study Goals
The weight loss drug Empatic, developed by Orexigen Therapeutics, Inc., met its main goals in its second Phase IIb clinical trial, which means researchers can now continue to a Phase III clinical trial, the last study before going to market. Empatic is one of two weight loss drugs currently under development by Orexigen. The other drug, Contrave, is currently in Phase III trials.
The current study included 729 people who were randomly assigned to receive either Empatic or a placebo. During the 24-week study, the patients who took Empatic lost at least 5 percent of their body weight, while those taking placebo registered a 14.7 percent loss. The significant weight loss credited to Empatic was not achieved without side effects, however, which include insomnia, hives, and headache. The percentage of patients who dropped out of the study (both treated and placebo patients) largely because of side effects was about 30 percent.
During the trial, the investigators also found that patients who took Empatic had a mean weight loss of 7.5 percent compared with 1.4 percent in the placebo group. The 6.1 percent difference between these two groups exceeds the Food and Drug Administration’s (FDA’s) requirements for approvable weight control medications.
The just completed Phase IIb trial follows a previous IIb trial of Empatic. In that study, which lasted 48 weeks, obese patients who took Empatic experienced weight loss of approximately 11 to 15 percent of body weight.
Empatic is a combination of the antidepressant bupropion (Wellbutrin) and the antiseizure medication zonisamide (Zonegran). Zonisamide has been shown to cause birth defects and to alter cognitive function, and therefore should not be taken by women of childbearing age. In this study, the researchers did not observe any significant differences between the drug treated group and those who received placebo regarding cognitive function, thoughts of suicide, or depression.
The weight loss drug Contrave is a combination of bupropion and naltrexone (Revia), a drug that is used to treat opiate and alcohol addiction. If it meets its goals in Phase III trials and gets FDA approval, Contrave it could be on the market in 2010 before Empatic.
Forbes September 30, 2009
Medical News Today, July 10, 2008
Reuters, September 30, 2009