DURBAN, South Africa, July 7 — A controversial approach to treating AIDS patients by giving them monitored "holidays" from complicated drug regimens may be one way to get the powerful drugs to victims in poorer nations, experts say.
The approach, known as structured treatment interruption, may also help patients in richer countries deal with the downside of the toxic drug cocktails, the researchers plan to tell the 13th International Conference on AIDS, which starts here on Sunday.
Dr Anthony Fauci, head of the National Institute of Allergies and Infectious Diseases (NIAID), will describe two experiments being sponsored by his institute, one of the U.S. National Institutes of Health, that are making researchers hopeful.
As the name implies, with structured treatment interruption (STI) a patient stops taking drugs for a while so the virus can come back just enough to provoke an immune reaction.
A few highly publicised cases have made headlines and Fauci said NIAID researchers had tested the idea in a few more people.
Patients like being off the drugs, which must be taken to strict timetables and which have side-effects ranging from diarrhoea to serious metabolic disorders.
"We are trying to get a more user-friendly regimen," Fauci said in a telephone interview ahead of his presentation.
"We really need to devise a regimen where people don't need to be on therapy for every single day of every single week of every single year."
Dr Salim Abdool-Karim, head of the scientific programme for the conference and a researcher at South Africa's Medical Research Council, said such an approach could save money. For rich patients and for those in countries whose governments can pay for expensive drugs, triple-drug cocktails are the norm.
In Africa, which bears the brunt of the AIDS epidemic, this is virtually impossible.
"The whole issue is that combination of triple therapy is expensive and is not going to be affordable for many countries," Karim said.
Taking two drugs together does help, but not as well or for as long as taking three or more drugs.
Karim said the interruption approach could allow patients to have triple-drug therapy for the price of dual drug therapy.
"STI works," Karim said, describing experiments in which, under careful supervision, patients took the drugs for a month, long enough to suppress the virus, and then stopped taking them for two months, until the virus rebounded.
"Triple therapy given this way might be as cost-effective as dual therapy," he said. "We might have an affordable way of giving triple therapy."
Drug-resistant virus can evolve when people do not take their drugs as directed. But STI relieves the virus of the "pressure" of drug therapy, letting it evolve back into a "wild-type" state that is more vulnerable to drugs. It may also train the immune system to better recognise and attack the virus, experts say.