Published Sunday, October 31, 1999
Common cold may be too big,
too unprofitable to fight
Judy Foreman / Boston Globe
Next time your throat is so raw you can't swallow and
your nose is so stuffed you can't breathe, think about
this:
Antiviral drugs for the common cold have passed
various stages of human testing. But the manufacturers
have decided that the drugs simply aren't profitable
enough to bring to market. Thanks a lot, guys.
You would think that with 61 million cases of the
common cold each year in this country alone, the sheer
enormity of the market would goad drug companies
into an all-out attack on cold viruses. And some
companies are still pushing to finish studies to get their
antiviral cold remedies to market.
But two other drug firms, Boehringer Ingelheim and
Bayer, have dropped their drugs faster than you can
say what Boehringer did in May: "In order to optimize
the use of human and financial resources, some
projects have been reassigned lower priorities where,
despite showing promise of considerable therapeutic
progress, the prospects for success in terms of clinical
development, potential indications or later production
were rated as less significant."
In other words, your suffering is not worth their
investment.
It is not a new sentiment. For decades, the common
cold was seen as a hopeless cause. For one thing,
there are about 200 viruses that cause colds. That
makes it tough to figure out which virus is at fault and
which drugs might help.
For another, colds rarely kill anybody, which means that
drugs must be very safe to justify taking them.
Still, the idea of making a drug that did not just relieve
symptoms, but actually attacked the virus itself is
obviously appealing.
After years of work, a number of scientists, among
them Timothy Springer, a molecular biologist at the
Harvard-affiliated Center for Blood Research in Boston,
figured out how.
They developed a kind of biological catcher's mitt to
snag viruses after they enter the nose but before they
get into cells lining nasal passages. It's a decoy
molecule called soluble ICAM-1 (intercellular adhesion
molecule-1).
Last May, Dr. Ronald Turner, director of pediatric
infectious diseases at the Medical University of South
Carolina, showed that the drug worked in people.
In a published study of 177 people, his team put drops
of cold viruses into volunteers' noses. Either before this
exposure or soon afterward, volunteers were given a
placebo or Boehringer's version of the ICAM-1 drug,
tremacamra.
The results showed that it reduced cold symptoms by
50 percent and reduced nasal secretions, as well. But
when the study came out, Boehringer shelved the drug,
which Turner says was "obviously a disappointment to
us."
Indeed, why a company would drop a drug at this point
"does seem odd," says Dr. Ken McIntosh, an
infectious-disease specialist at Children's Hospital in
Boston.
But Bayer has done likewise. Human safety tests of its
ICAM-1 drug "were successful," says Jeffrey Greve, a
molecular biologist who heads the company's
molecular technology unit in Berkeley, Calif.
Nonetheless, its ICAM-1 will go no further unless the
company finds a "commercial partner" to develop the
drug. It boils down, Greve says, to "a money issue."
ICAM drugs are made by genetic engineering, an
expensive technology that in other products can cost as
much as $1,000 a dose.
So are we destined to continue to suffer long, snuffly
winters? This year, probably, but perhaps not forever.
At a recent conference on antimicrobial agents,
ViroPharma Inc. of Exton, Pa., reported encouraging
results with its drug called pleconaril, a so-called
capsid binding agent being tested against viral
meningitis as well as cold viruses.
Cold viruses come cloaked in an outer shell, which they
must shed before replicating. Pleconaril seems to
prevent this shedding, stopping the virus in its tracks.
In double-blind, placebo-controlled studies involving
more than 1,000 patients, pleconaril reduced the
duration of cold symptoms by 3« days. The company
expects to seek federal approval of the drug (initially,
for meningitis) early next year, says spokeswoman Kori
Beer.
Meanwhile, researchers at Agouron Pharmaceuticals in
San Diego are pursuing a drug that still goes by its
numerical name, AG7088, and which works like the
protease inhibitors used for HIV. Agouron's drug blocks
an enzyme that's needed for the cold virus to chop up
its proteins into usable segments.
So far, the Agouron drug, a nasal spray, has been
tested in several hundred people, and seems to be
active against about 50 strains of cold viruses. It is now
being tested in hundreds more people, says
spokeswoman Joy Schmitt.
Outside the mainstream pharmaceutical establishment,
researchers at Gel Tech LLC in Woodland Hills, Calif.,
have begun marketing a nasal spray called Zicam,
which retails for $10 to $13. It is marketed as a
homeopathic remedy, which the U.S. Food and Drug
Administration does not approve or disapprove, and
only loosely tracks.
The product has been in the works since 1995, says
one of its creators, physiologist Charles Hensley. It is a
form of ionized zinc that may work by binding to the
same tiny part of a cold virus that the ICAM decoy
molecule latches onto.
Hensley says Zicam reduces the duration of cold
symptoms from nine days to 1«, but the problem is
there is only Gel Tech's word to go by because there
are no published independent studies that confirm his
statements.
-- Judy Foreman is health columnist for the Boston
Globe. |
