BEIJING,
Nov. 8 (Xinhuanet) -- Researchers in U.S. reported that the first human test of
a potential new gene therapy for HIV -- the virus that causes AIDS -- worked
better than expected, and was encouraging enough for researchers to launch a
more extensive trial.
A team from the University of Pennsylvania
School of Medicine removed immune cells from the patients and introduced a virus
called a lentivirus into the cells. This change prevents HIV from reproducing
and, in the laboratory, has the ability to fight HIV in cells that have not been
treated, they explained in the report.
One of the five patients involved in the test had a
sustained decrease in the amount of virus, while immune cells and strength
of the immune system increased in other four patients during the nine-month
study.
Importantly, after up to 36 months, there was no sign
of dangerous mutations caused by the insertion of the gene, a problem that has
caused cancer in other gene therapy trials.
Research team leader Carl June said the results from
the clinical trial "are encouraging -- particularly since these are late-stage
patients -- and demonstrate that gene therapy has the potential to treat HIV and
other serious human diseases."
However, "just because this has produced encouraging
results in one or two patients doesn't mean it will work for everyone. We have
much more work to do," said co-author Dr. Bruce Levine.
Now, the team has launched a phase II test that will
involve more patients, including some whose HIV is controlled by drugs. In this
test the patients will get more than one transfusion of the treated cells. Those
on standard drug treatment, following the new therapy, will be asked to
interrupt their drugs to see if the infection returns.
The AIDS virus infects close to 40 million people
worldwide and has killed 25 million. A cocktail of drugs can help control
infection, but there is no cure and no vaccine.
The drugs cause sometimes severe side-effects in some
patients and the virus can evolve resistance, so that patients have to move to
new drug combinations.
Gene therapy is a promising but troubled field of
research based on the premise that altering genes can cure disease. It has cured
only a few patients, and some have developed leukemia as a consequence. One gene
therapy volunteer died in 1999.
(Agencies)
