HIV Beats Researchers at Hide and Seek
In early results from a handful of patients, Fauci says interrupting therapy -- either one week on, one week off or two months on, one off -- appears to control the virus as well as constant treatment while reducing the cost. Eventually, the study will enroll 70 patients: 35 who will take HAART continuously and 35 who will receive intermittent therapy.
He says it's still too early to know whether there will be fewer side effects, but the patients in the study are excited about avoiding the "extraordinary burden" of the pill-intensive therapy, in which one must take as many as 40 pills a day.
But he adds that physicians shouldn't move too quickly: "Don't try this until the trial is complete," Fauci says.
One fear in interrupting therapy is that the virus will be able to recover and perhaps evolve into strains resistant to the drugs. But Fauci says that fear only applies to "sub-optimal therapy," in which patients don't follow treatment plans, and is unlikely to arise in his study.
One reason for attempting to find alternatives to continual HAART treatment is the problems of side effects and difficulty with patients sticking to the regimens. Researchers from the CDC have said that less than one-fourth of patients are adhere to their treatment 95% of the time or more.
Scott Holmberg, MD, a senior epidemiologist for the CDC, says HAART is effective for more than 12 months in only about one-third of patients. Others, Holmberg says, must regularly change their drug regimes in order to maintain low blood levels of HIV, which means that drug options "are increasingly being exhausted by the people who need them."
Holmberg analyzed information from more than 1,600 AIDS patients across the U.S. He found that HAART use has climbed from 4% at the end of 1995 to 87% in late 1999. At the same time, AIDS deaths dropped by more than 90%.
But HAART failed to keep virus levels low for more than a year in 64% of patients, Holmberg says. The average length of time that the virus was suppressed was just over 10 months, he adds. Subsequent HAART regimens kept the virus under control for a shorter time; shorter still if a third regimen was used.