Feb. 9 (Bloomberg) — The U.S. government and the richest
charity are offering bounties to a new wave of scientists to
wipe out HIV, the virus that causes AIDS and is one of the
world’s biggest killers.
Frustrated by one failure after another, the U.S. is asking
scientists to outline a major program to find a cure for HIV,
while the Bill & Melinda Gates Foundation in Seattle is offering
grants of $100,000 for researchers working on ways to drive the
virus from patients’ bodies for good. Scientists are responding
with new methods to stamp HIV from human cells and tissues where
traces of it can hide for years, evading treatment.
Experimental vaccines and sexual gels called microbicides
have failed to prevent the spread of the disease, which strikes
2.7 million new patients each year. The challenge is all the
more urgent since Merck & Co.’s Ad5 vaccine, the most promising
effort to date, flopped in 2007.
“If the vaccine had worked, I don’t think any of this
would be happening,” said David Margolis, a doctor at the
in Chapel Hill, who has been
working for years to cure HIV. “Getting so close to an
effective vaccine and then having to start from scratch again
has made people wisely step back and re-evaluate the whole
playing field of options.”
asked scientists last
year to describe how they would eliminate HIV from its hideouts
in body cells, where it can evade detection and lie dormant for
years before springing back to growth. The effort, which may
involve scientists at Harvard University, the University of
California at San Diego and other institutions, will be a major
topic at the annual
, beginning on Feb. 8 in Montreal.
Margolis, along with researchers at
& Co.,
,
,
and other
institutions, proposed a government-funded effort to discover
how HIV persists in the body even after powerful drugs drive the
virus below levels detectable by conventional means. The
Seattle-based Gates Foundation, the world’s biggest private
charity, is asking for proposals aimed at the same goal.
To cure HIV, scientists must devise a way to expunge the
virus from the human body. The most-effective HIV drugs so far
aren’t powerful enough to accomplish that goal.
For about 12 years, doctors have known that HIV can lie
dormant in cells, where they evade detection by the body and are
safe from drugs floating through the bloodstream and penetrating
tissues. HIV hijacks genetic machinery to make copies of itself
that are released into the body as the infected cell dies.
“It’s very easy to get the number of viruses circulating
in the system down to an undetectable level,” said
, director of the National Institute of Allergy and
Infectious Diseases, in a telephone interview. “However, to
knock it out, we’ll either have to get true eradication, or get
the reservoir of virus that’s inside cells so low that it can’t
come back.”
Decreasing the amount of virus hiding inside cells might
allow the body’s protective immune system to handle the
infection on its own, without drugs. That would be equivalent to
a “functional cure,” similar to a remission that cancer
patients achieve when they don’t have to take drugs, Fauci said.
Latent HIV acts like a smoldering fire that can burst into
flame at any time. What that means, said
, director
of the University of North Carolina’s Center for Global Health
and Infectious Diseases, is that without a cure, once a patient
is diagnosed with HIV and begins taking drugs, the need for
taking medicine disease never ends.
Pressure to find a cure has increased in the two years
since Merck’s Ad5 vaccine flopped in 2007. Another approach to
treatment, gels to prevent HIV transmission during sexual
intercourse, also proved futile.
For now, that leaves only the option of giving lifelong
drugs to sustain people already infected. The lifetime cost of
treatment for U.S. HIV patients is more than $600,000. The U.S.
has committed $50 billion over the next five years to combat HIV
in Africa, where cheap generic drugs are staples of treatment,
Cohen said.
“Can we sustain this spending for 50 years?” Cohen said
Jan. 23 on the infectious-disease ward of the University of
North Carolina Hospital in Chapel Hill. “We can’t treat our way
out of the epidemic. Cure of HIV is an idea whose time has
come.”
Margolis would like to start testing a drug, Merck’s
, that shows potential to flush out latent HIV. He is
hoping that the medicine will turn on the growth of HIV in the
cells where it is latent, so that the virus will kill them and
its hiding place will be gone.
To test Zolinza and other drugs, scientists are searching
for patients in the earliest stages of HIV infection. Their
cases may show how to limit the number of cells with latent
infections, and might be the first candidates for curative
treatment, researchers said.
“People are starting to take this idea seriously again,”
Cohen said in an interview at his office. “The cancer field is
always talking about cure: Walk for the cure, run for the cure,
ride for the cure.”
He added, “It’s a good thing, it’s inspirational, and now
it’s time for us in the HIV field to do the same.”
.
Last Updated: February 9, 2009 00:00 EST