A cure for colds and flu? Researchers close in
Reuters, Sunday, September 27, 1998 at 00:07
(Published on Saturday, September 26, 1998 at 08:30)
By Maggie Fox, Health and Science Correspondent
WASHINGTON, Sept 26 (Reuters) - Could there be a cure out
there not just for the common cold, but for the miseries of
flu?
Researchers at several companies are reporting this weekend
on a drug that might stop the most common cold virus in its
tracks, drugs that ease the miseries of flu, and even drugs
that can stop flu from infecting people.
They have told a meeting of the American Society for
Microbiology in San Diego that there is finally hope for
victims of flu, which not only causes a wretched week or two of
headaches, coughing and sneezing, but kills thousands every
year.
Glaxo Wellcome (ISEL:GLXO) says its drug Relenza, shown last
year to shorten a flu attack by one day, can be used almost as
a vaccine against the virus.
Tests on college students showed Relenza, known generically
as zanamivir, could reduce flu risk by 67 percent. Eleven
students who used Relenza, or 2 percent, caught a flu virus
sweeping their campus, while the 34 people, or 6 percent, who
did not take the drug caught the flu.
The drug comes in the form of a powder and is inhaled using
a pocket-sized puffer device.
Another study at the University of Virginia showed
zanamivir, given intravenously, prevented flu infection in six
out of seven volunteers.
Another drug, GS4104, developed by F. Hoffmann-La Roche
Ltd. (ZSE:ROCZ.G) and California biotechnology company Gilead
Sciences Inc. (NASDAQ:GILD), reduced a flu attack by about a third,
and relieved symptoms.
Both drugs are in Phase III clinical trials, the last stage
before a company can ask for approval from the U.S. Food and
Drug Administration (FDA).
Both target the same enzyme in the virus -- neuraminidase.
It is used by the virus to replicate itself.
The drugs attach themselves to the enzyme, effectively
clogging up the mechanism used by the virus to attack cells,
and making it helpless.
Another drug known as FluMist works as a nose spray
vaccine. FluMist, made by Aviron (NASDAQ:AVIR), has been shown to
give 93 percent protection against infection and 98 percent
protection against the ear infections that accompany flu in
many children.
Dr. Robert Belshe of Saint Louis University, who tested the
drug, thinks it will offer a much easier way to vaccinate
children and others wary of needles.
Current vaccines work fairly well, with about a 30 percent
failure rate. But there are countless strains of flu that
mutate every year and the virus kills between 10,000 and 40,000
Americans each year.
There are two other anti-flu drugs already on the market --
amantadine, made by several companies, and rimantadine, made by
Forest Pharmaceuticals. But they only fight the influenza A
strain, while Relenza and GS4104 seem to work against both
influenza A and B.
While influenza is the more serious disease, the common
cold is even harder to treat.
But researchers at Agouron (NASDAQ:AGPH) think they have a good
candidate. They have only tested their drug in test tubes, but
say it stops 46 of the more than 100 known human rhinoviruses
(HRVs), one of the major causes of colds.
"We have been able to show that this drug has shown very
potent antiviral activity against all the HRVs that we tested,"
Agouron's Dr. Amy Patick said in a telephone interview.
In more experimental results, Columbia, Maryland-based
Novavax Inc. (AMEX:NOX) reported that test tube trials of its
drug, a "nanoemulsion" known as BCTP, showed it reduced levels
of antigens for influenza A by 99.6 percent.
Antigens are the chemicals to which the immune system
responds, and are a good indicator of how much virus remains in
the system.
In a second study, mice that had BCTP and virus sprayed
into their noses stayed healthy, while three mice that got a
virus alone developed severe pneumonia and two died.
Novavax thinks BCTP might kill the virus outright and in a
second presentation to the meeting said it killed anthrax, as
well as the deadly spores spread by the anthrax bacillus.
Copyright 1998, Reuters News Service |
