In a Texas laboratory, rhesus monkeys lost an average of 11 percent of their body weight after just four weeks on the experimental drug, the researchers said.
"We're incredibly pleased by the results," Renata Pasqualini, a researcher at the University of Texas M.D. Anderson Cancer Center, told the Houston Chronicle Thursday.
Primates are considered a good model for humans, and the drug could undergo testing in humans during the next few years.
The drug uses a biological agent that homes in on the blood vessels that feed fat cells, transporting a tiny amino acid that effectively kills the blood vessels, effectively strangling the fat cells.
Most previous experimental drugs have sought to suppress appetite by altering the chemistry of brain.
Because the new drug, named Adipotide, may be one that has to be taken for the rest of one's life to be effective, the regulatory and safety hurdles to bringing it to market will be significant, the Chronicle reported.