SAN DIEGO – Based on results from a large, multi-center weight loss study led by a researcher at Scripps Health in San Diego, Calif., the makers of an obesity drug candidate plan to seek approval from the Food and Drug Administration (FDA).
The drug, Contrave, is an investigational therapy that combines a sustained release version of naltrexone, an opioid blocker used to treat addiction, and buproprion, an antidepressant prescribed to help people stop smoking.
In three phase III clinical trials, the drug met an FDA requirement for efficacy – which includes a five percentage point difference in weight loss between the drug and placebo.
“These two drugs have been in use for more than a decade other purposes,” said Ken Fujioka, MD, lead investigator of the Contrave trials and director of the Center for Nutrition and Metabolic Research at Scripps Clinic. “That lessens the chance of a surprise adverse reaction.”
In one trial, 48 percent of obese patients on Contrave lost at least 5 percent of their body weight, compared with 16 percent of those given a placebo. In another trial, 56 percent of patients achieved at least 5 percent weight loss compared to 17 percent of the placebo group. In a third trial involving people with type two diabetes, 45 percent of patients on Contrave lost greater than or equal to 5 percent of their body weight compared to 19 percent given a placebo.
The three trials each lasted 56 weeks. All incorporated a standard diet and exercise regimen.
“The data gives us greater confidence that Contrave has the potential to help obese patients, even those with diabetes, to initiate and sustain weight loss and improve their health," said Dr. Fujioka.
More than 4500 people participated in the clinical trials, but around 40 percent of them dropped out. The most severe side effects included one case of gall bladder infection and one person who had seizures. Common side effects among study participants included nausea, constipation and headache. Nausea was the leading adverse event resulting in discontinuation.
San Diego-based Orexigen Therapeutics, the makers of Contrave, plan to seek approval for the drug from the FDA in early 2010.
Founded in 1924 by philanthropist Ellen Browning Scripps, Scripps Health is a $2 billion nonprofit community health system based in San Diego, Calif. Scripps treats a half-million patients annually through the dedication of 2,600 affiliated physicians and 12,700 employees among its five acute-care hospital campuses, 19 outpatient centers and home health care services.
Recognized as a leader in the prevention, diagnosis, and treatment of disease, Scripps is also at the forefront of clinical research, translational science and graduate medical education.