Targeted drug melts fat, weight and waistlines in obese monkeys

An experimental drug that directly reduces fat by destroying the blood vessels that support it caused an 11 percent weight loss in obese rhesus monkeys in a month's time.

"Development of this compound for human use would provide a non-surgical way to actually reduce accumulated white fat, in contrast to current weight-loss drugs that attempt to control appetite or prevent absorption of dietary fat," says Renata Pasqualini, Ph.D., professor in MD Anderson's David H. Koch Center for Applied Research of Genitourinary Cancers.

"We're greatly encouraged to see substantial weight loss in a primate model of obesity that closely matches the human condition," Pasqualini says.

Treated monkeys had corresponding reductions in waist circumference and body mass index. Untreated control monkeys were largely unchanged during the study.

Imaging studies showed treated monkeys lost 38% of their body fat, including 27% of their abdominal fat, indicating that weight loss was caused by fat reduction and not the loss of other types of tissue.

At the start of the study, none of the monkeys were diabetic, but they did have heightened insulin resistance, which raises risk of developing type 2 diabetes and cardiovascular disease. Treated monkeys showed marked improvements in insulin resistance - using about 50 percent less insulin after treatment.

Lean monkeys in a dosing study did not lose weight when treated with the drug.

"Obesity is a major risk factor for developing cancer, roughly the equivalent of tobacco use, and both are potentially reversible" says Wadih Arap, M.D., Ph.D., also professor in the Koch Center. "Obese cancer patients do worse in surgery, with radiation or on chemotherapy - worse by any measure."

Arap, Pasqualini and colleagues are developing a clinical trial of the drug for obese prostate cancer patients to submit to the U.S. Food and Drug Administration for approval.

The scientists published their findings in Science Translational Medicine.

Additional resources MD Anderson news release Science Translational Medicine paper