Old Drugs Combine to Produce New Weight Loss Benefit

The maker of an investigational diet drug -- actually a combination of a drug used to treat alcohol dependence and an antidepressant -- said the combo produced significant weight loss in three clinical trials.

In the concurrent trials with 4,500 obese patients, those given bupropion/naltrexone (Contrave) daily for 56 weeks lost at least 5% of body weight, the FDA benchmark for efficacy of diet drugs, according to a statement from drug maker Orexigen Therapeutics of San Diego.

Bupropion is an antidepressant marketed under the name Welbutrin that is also used as a smoking cessation aid under the name Zyban. Naltrexone is an opioid receptor antagonist used to treat drug and alcohol dependence.

The company said it planned to file a New Drug Application with the FDA during the first half of 2010.

The findings were unveiled during a teleconference with reporters at 8 a.m. EDT, well before the opening of the markets in New York -- the company's stock trades on Nasdaq.

The COR trials (Contrave Obesity Research) randomized patients to bupropion/naltrexone or placebo.

The COR I trial enrolled 1,742 obese patients to two active doses (bupropion 360 mg plus naltrexone at 16 mg or 32 mg) or placebo. After 56 weeks, patients randomized to the 32 mg naltrexone combination lost a mean of 8.1% of baseline body weight or about 18 pounds versus a loss of 1.8% of baseline body weight or four pounds in the placebo group (P<0.001).>

The results were similar in the COR II trial, which recruited 1,496 patients. A third trial examined the combination in patients with diabetes and found that those on active therapy lost a mean of 5.9% of baseline body weight or 13.5 pounds versus 2.2% and five pounds in the control group.

The company said that combined data from the three trials revealed that after 56 weeks of treatment mean blood pressure was unchanged among patients taking the combination, whereas controls had a slight decrease in blood pressure.

There was also a slight increase in pulse rate among patients randomized to bupropion/naltrexone.

Source : www.medpagetoday.com