NEW YORK (Reuters Health) - A drug currently being studied for cancer treatment may hold promise as an HIV therapy, researchers have found.
In cell culture experiments, scientists discovered that the drug, called flavopiridol, blocks HIV cells from making copies of themselves. Moreover, flavopiridol worked at concentrations that are much lower than those being tested in cancer trials--suggesting that HIV patients would be less likely than cancer patients to suffer side effects from the drug.
The findings were published in the July 21st online issue of the Journal of Biological Chemistry.
Researchers led by Dr. David H. Price of the University of Iowa in Iowa City found that lavopiridol hinders a critical step in HIV replication called transcription.
The drug acts on an enzyme called P-TEFb that helps control the transcription process. This fact could help get around one of the major obstacles in treating HIV--the ability of the virus to mutate into drug-resistant strains.
All of our current drugs against the AIDS virus target (virus) proteins, which go through mutations at a very high rate,'' Price said in an interview with Reuters Health.
Since proteins like P-TEFb are produced by body cells, and not viral cells, patients would theoretically not develop resistance to flavopiridol or drugs like it, according to Price.
One concern with targeting body cell proteins instead of HIV cells is that it might produce intolerable side effects in patients. Price noted, however, that flavopiridol has so far gotten through cancer trials without serious side effects.
Some of the trial patients have suffered diarrhea and a condition called proinflammatory syndrome, but the outlook may be different for HIV patients.
The fact that flavopiridol seems to work at a much lower concentration (against HIV) suggests that the side effects might go away,'' Price said.
The answers to these questions await trials in HIV patients, which Price said could begin quickly if animal research confirms his team's findings.
Flavopiridol, he noted, has already ``gotten past many hurdles'' in cancer trials. If it does work against HIV, Price added, that would open the door for the development of other drugs that target P-TEFb.