NYT article about new asthma treatment (anti-IgE).
(One thing that I always find astounding is how high the "cure" rate is amongst the placebo-receiving test subjects ! This is just crazy ...)
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July 11, 2000
Working to Block Allergens at the Source of the
Attack
By RANDI HUTTER EPSTEIN
A few years ago, 13-year-old
Drew Williams's asthma
was so severe, he could
not even go to a movie. Once a
fleck of dog dander, a remnant
from a pet-owner who previously
had his seat, sparked an attack.
At school in Dillon, Colo., Drew's
desk had to be far from
classmates who owned furry
animals. And that was despite
high doses of asthma medications
he took every morning to open
his airways.
Today, taking a new experimental
treatment, called anti-IgE, Drew
can go anywhere he wants
without fear that he will stop
breathing.
The anti-IgE shots changed his
life, Drew said.
"Before, I was on tons and tons of medication."
Still, he added, "If I touched a dog, I'd be rushed to the hospital. Now I can't
really pet dogs, but I can toss them a ball."
Drew is among 2,000 severe asthmatics participating in trials of anti-IgE, one
of a new class of treatments aimed at preventing allergy and asthma attacks.
The treatments, still experimental, are aimed at stopping the attacks at their
source. Most treatments simply treat the symptoms.
For nearly 80 years, scientists have known about the antibody IgE or
immunoglobulinE, which is one of five kinds of antibodies that fight foreign
substances. IgE is the one that reacts against allergens causing hay fever and
other allergic reactions. But only recently have scientists considered using it
for therapy. Shaped like the letter Y, IgE has two tails that hang freely and
one that sticks to mast cells. When an allergen enters the body of a
susceptible person, it sticks to one of the free ends of IgE, prompting the
antibodies to link together. This cross-linking, in turn, provokes the mast
cells to spew its substances -- cytokines, leukotrienes and histamines -- that
cause itchy eyes and clogged airways. The anti-IgE shots are made of a
substance that blocks IgE right where it attaches to the mast cell, foiling the
chemical cascade.
Other new treatments block a cytokine or one kind of leukotriene.
Dr. Peter Barnes, an expert on allergies at the National Heart and Lung
Institute in London, said the encouraging news was that the shots seemed to
be working for severe asthmatics, while other new approaches had a limited
effect because they were too specific.
For instance, a drug that blocks one kind of leukotriene may prevent blocked
airways but have no effect on itchy eyes.
The hope is that this new family of treatments will be effective and lead to
fewer side effects than oral steroids, which are used to treat patients with
severe disease. Chronic use of oral steroids can stunt growth in children and
lead to brittle bone disease and high blood pressure.
So far, a few small studies suggest that patients getting anti-IgE shots once
or twice a month suffer fewer flare-ups and need less medication. Some
patients are weaned off other drugs completely.
The results of two small random trials, in which half the participants got the
treatment and the rest a placebo, were presented at the American Academy of
Asthma and Immunology in San Diego in March. One study included 334
asthmatic children ages 6 to 12. About 55 percent of those who got the shots
no longer needed the inhaled steroids, compared with 39 percent of those
who got a placebo. Another study of 525 adults found that those who got
real treatment, rather than a placebo, suffered fewer asthma attacks: 21.3
percent versus 32.4 percent.
These results confirm an earlier report, published in December in The New
England Journal of Medicine. In that study 314 patients continued with their
steroid treatment and in addition got either high-dose anti-IgE, low-dose
anti-IgE or a placebo. Asthma symptoms, like chest tightness or wheezing
were reduced by 42 percent among the high-dose group, 40 percent in the
low-dose group, and 30 percent in the placebo group.
Anti-IgE is being developed by Genentech, Novartis Pharma AG and Tanox,
but it has not received approval.
Anti-IgE could have a major impact, said Dr. Henry Milgrom, one of the
investigators at the National Jewish Medical and Research Center in Denver.,
a leading lung disease hospital. But, he said: "I am reluctant to paint too rosy
of a picture. There is confirmation that has to come before you can draw
firm conclusions."
Other experts said the notion of allergy medication aimed at the immune
system was exciting, but they added that they were waiting for the results of
large trials to
ensure the drugs were effective and had few side effects.
Dr. Allan Weinstein, an internist in Washington and the author of "Asthma:
The Complete Guide to Self-Management of Asthma and Allergies"
(Ballantine, 1989), said: "The greatest concern is that while the death rate for
so many diseases has dropped, it has not budged for asthma. This treatment,
if proven effective in large studies, could be particularly useful for those with
difficult-to-manage disease."
Drew said he was grateful that he stuck with the study. "In the beginning
when they told me it was shots twice a month, it was a little scary," he said.
"But once I started, it wasn't so bad. And now I can play without having to
take extra medicine. It used to be running to first base would take it out of
me and I'd reach for my inhaler. Now I can play baseball without worrying. I
can really do anything I want."
Copyright 2000 The New York Times Company |
