Researchers from the University of Maryland’s Institute of Human Virology may have found a way to make one of the newest antiretrovirals even more effective. Abacavir (Ziagen), Glaxo Wellcome’s new nuke, works as a defective mimic of guanosine, a building block of all cells’ genetic material, that HIV needs for replication. David Oldach, MD, and David Margolis, MD, hit upon mixing abacavir with mycophenolic acid, a drug used in transplant patients to help prevent organ rejection by depleting the guanosine in white blood cells. The scientists reasoned that if the transplant drug made fewer real guanosine building blocks available to HIV for replication, then it could help abacavir’s fakes boost the odds against the virus. In fact, the combo made abacavir six times better at blocking HIV, which raises the possibility of using lower, less toxic doses of the drug. “You’d be hard-pressed to find another combination of anti-HIV drugs with this profound an effect,” Margolis says. Remarkably, this experimental treatment went from first thought to human trials in a mere six months.
Less Is More