Latest Research Supports New AIDS Drug

The U.S. Food and Drug Administration approved maraviroc, known by
the brand name Selzentry, in August 2007 after a 24-week study showed
it had beneficial effects. It was the first new HIV oral medication approved in more than a decade.

The
new study followed the patients for another 24 weeks, and found that
more than 40 percent of them had reduced levels of the AIDS-causing HIV
virus in their blood.

"We're really able to do something we
haven't been able to do before, essentially rescue someone with
drug-resistant virus and gain control of their HIV infection," said
principal investigator Dr. Roy Gulick, director of the Cornell HIV
Clinical Trials Unit at Weill Cornell Medical College in New York City.

Since
the 1990s, new generations of drugs have made major strides in treating
the virus that causes AIDS. Patients are often able to control the
levels of the virus in their bodies and live for years.

However,
the virus has the ability to mutate and evolve, and it's often able to
adjust to resist the killing powers of medications. Some people also
become newly infected with strains of HIV that are already immune to
certain drugs.

"Roughly, between a quarter and a third of
patients [are resistant] to the classic classes of drugs," Gulick said.
"These are patients who really need treatment options."

The new study, published in the Oct. 2 issue of the New England Journal of Medicine,
followed 1,049 HIV patients who were resistant to three classes of HIV
drugs. Some patients received doses of maraviroc, while others received
a placebo. The study was funded by Pfizer Inc., the maker of the drug.

Between
42 percent and 47 percent of the patients taking maraviroc reached
reduced levels of the AIDS virus in their bodies, compared to 17
percent of the placebo group.

"There were no apparent side
effects or toxicity differences in patients that got maraviroc vs.
placebo," Gulick said. "It looked safe and generally well-tolerated
over 48 weeks."

The drug works by preventing the AIDS virus from
binding to a receptor on immune cells known as CCR5. Some people are
born without the receptor and are naturally resistant to the AIDS virus.

There
are caveats with maraviroc: Doctors must give a $1,900 test to patients
to make sure their strain of HIV would be susceptible to the drug,
Gulick said. Also, researchers must follow patients on maraviroc to see
if any unusual medical problems affect them over time, he said.

Latest Research Supports New AIDS Drug

By Randy Dotinga
HealthDay Reporter

WEDNESDAY, Oct. 1 (HealthDay News) -- New research offers more evidence that a new class of AIDS drug can provide major benefits for certain patients who have become immune to existing medications.

Dr.
Barry S. Zingman, medical director of the AIDS Center at Montefiore
Medical Center in New York City, and one of the doctors taking part in
the study, said he has had good experiences prescribing maraviroc.

However,
"many patients who need a new treatment option cannot use it" because
they don't have the necessary strain of HIV, said Zingman, who has
received research grants to study the drug.

In addition, he said,
"there are significant interactions between maraviroc and other
medications for HIV infection, making it a bit complicated to prescribe
in the combination regimens that are standard around the world."