Rethinking Healthcare

Obese monkeys lose weight, shrink waistlines with novel drug

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Researchers have come up with a new drug that targets fat tissue by destroying its blood supply. Monkeys have lost 38% of their body fat and are at lower risk for type 2 diabetes.

Researchers are working on a new drug that targets fat tissue by destroying its blood supply. So far, it works in monkeys who had became spontaneously obese all by themselves.

Right now, there are only 2 types of weight loss drugs that are approved by the US Food and Drug Administration: an appetite suppressant and a fat inhibitor. But they sort of have toxic side effects.

Previous mouse studies have shown that targeting the blood vessels of fat tissue (or white adipose) reduced a third of their body weight. White adipose just under our skin stores fat and provides us with insulation.

"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 study author Renata Pasqualini of the University of Texas M. D. Anderson Cancer Center.

But because many drugs fail in the transition between rodents and primates, the team set out to demonstrate in monkeys the weight-loss effects seen in mice.

The drug selectively binds to a protein on the surface of fat-supporting blood vessels and kills those cells within blood vessels of adipose tissue. (It’s like starving a tumor by cutting off the blood vessels that supply it.) Without blood supply, fat cells are reabsorbed and metabolized.

In 10 rhesus monkeys, one month of treatment resulted in:

  • Rapid weight loss. Up to 15% of their body weight.
  • Reduced body fat. MRIs scans show that the treated monkeys shed 38.7% of body fat on average. Pictured, monkey before and after (red is fat).
  • Slimmer abdominal circumference (waistline). Up to 14%.
  • Improved insulin resistance, which makes them at lower risk for type 2 diabetes and cardiovascular disease.

The monkeys remained bright and alert throughout, interacting with caretakers and demonstrating no signs of nausea or food avoidance. Though, side effects included increased amounts of urine and slight dehydration, both symptoms of mild kidney failure.

A company called Ablaris Therapeutics has licensed rights to the obesity therapy and is working with the FDA to test it in people, ScienceNOW reports.

The study was published in Science Translational Medicine last week.

Images: Science/AAAS

Janet Fang

Contributing Editor

Janet Fang has written for Nature, Discover and the Point Reyes Light. She is currently a lab technician at Lamont-Doherty Earth Observatory. She holds degrees from the University of California, Berkeley and Columbia University. She is based in New York. Follow her on Twitter. Disclosure