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....And
this: Radiation Sickness Drug Developed
Military Health Officials Hope Medicine Could Protect First
Responders
By John Mintz
Washington Post Staff Writer
Monday, May 19, 2003; Page A02
U.S. military officials are expressing enthusiasm about an
experimental drug that they say could protect the health of
troops, police officers and emergency medical personnel who
respond to terrorist attacks involving nuclear weapons or
radiation-spewing "dirty bombs."
The drug being developed by Hollis-Eden Pharmaceuticals Inc.
of San Diego appears to offer significant protection from
radiation sickness, which would kill many more people in
nuclear attacks than the initial blast, military officials and
experts said.
"We want it on the fast track," said Navy Adm. James
A. Zimble, a top military health official who is president of
the Uniformed Services University of the Health Sciences in
Bethesda. "We've been very encouraged by the very
positive results" of tests on animals, he added.
Experts cautioned that more research needs to be done to prove
the drug's effectiveness and safety when administered to
humans. The vast majority of new drugs that appear promising
in animal studies never gain approval for humans. But
radiation specialists said tests on this drug with mice, dogs
and monkeys suggest that it will work in people and will not
prove toxic.
Since the 1950s, military researchers have scrutinized
thousands of compounds in a search for something that could
protect troops in a nuclear war zone, but have failed. This
drug is the first to hold such promise, said Mark H. Whitnall,
a top researcher at the Armed Forces Radiobiology Research
Institute in Bethesda, which is working closely with
Hollis-Eden on the drug.
"My personal opinion is any agency dealing with emergency
response to terrorist events should be interested" in the
new drug, Whitnall said.
U.S. military officials are encouraged by results from animal
studies that appear to demonstrate that the drug, called
HE-2100, offers protection when administered before radiation
exposure as well as a few hours after exposure, or even later.
This suggests it could be given to military personnel or
firefighters when it is known that they will be entering a
radiated zone or as they are leaving one. Currently, there is
no safe medicine to give people after they are exposed to
dangerous levels of radiation, experts in the field said.
Radiation severely compromises the body's immunity to disease,
so most fatalities caused by a nuclear explosion or dirty bomb
blast would come from infections, including influenza and
pneumonia, beginning a week to six weeks after detonation,
medical experts said. A dirty bomb is a conventional explosive
attached to radioactive material, which is spread when the
device goes off.
HE-2100 buttresses the immune system, in particular the
infection-fighting powers of bone marrow, which is most
vulnerable to radiation. The drug protects the bone marrow's
ability to continue creating infection-fighting cells called
neutrophils even after radiation exposure. The loss of too
many of these cells brings on a condition called neutropenia,
which leads to infections and possibly death.
HE-2100 stimulates neutrophil production by causing cells that
become neutrophils to mature and to be released into the
bloodstream.
In a Hollis-Eden study completed earlier this year, monkeys
that received a near-lethal radiation dose and did not receive
the drug suffered severe neutropenia 50 percent of the time
over the next 21 days. By contrast, monkeys given HE-2100
about three hours after being dosed with radiation, and then
for the following seven days, suffered the same effects only 9
percent of the time. None of the monkeys suffered ill effects
from HE-2100, the firm said.
By staving off radiation-related infection and illness in the
weeks after a nuclear event, HE-2100 can, it appears,
"bring people over that hump in time, where, without it,
they would die," said David Grdina, a professor of
radiation and cellular oncology at the University of Chicago.
"There are definitely applications for homeland security
in this drug," Grdina said. Even so, Hollis-Eden is
pursuing the drug's development through the U.S. military, as
it has for several years, rather than switching to the
Department of Homeland Security.
Some civilian officials say developing medical protections
against radiation is less of a priority than working on cures
for bioterror agents, which they view as the gravest current
terrorist threat.
In any case, Whitnall added that the fact that HE-2100 has
shown such encouraging results in tests involving three
different species suggests it will be successful in humans.
"It protects against radiation damage; there's no doubt
about that," said William McBride, a radiation biologist
at the University of California in Los Angeles. "The
question is: How much can you give a person" before it
proves toxic? "It seems non-toxic so far. It's
encouraging they got it into primates."
The only other drug that has been shown to protect animals
from radiation, ethyol, must be given before radiation
exposure, and can be highly toxic. Hollis-Eden and military
officials said HE-2100 is the only compound on the horizon
that has its potential.
The firm estimates that an eight-day course of the drug would
cost as much as $100. Military officials said the idea is to
stockpile enough doses across the country to treat both first
responders and as many people in the general population as
could be radiated in an attack.
The Food and Drug Administration has decided the firm can seek
approval of the drug under a new set of streamlined procedures
for substances believed to protect people in
nuclear-biological-chemical attacks. Because it would be
unethical to irradiate human beings to determine whether the
drug works, the FDA says the company can rely on the animal
studies to show its efficacy, and give the HE-2100 to people
to test for adverse reactions.
The drug is being developed in injection form, but Hollis-Eden
is looking into developing it in pill form.
Other drugs also protect humans in radioactive crises, but
only from a limited range of radioactive isotopes. Potassium
iodide pills, if given within hours of a radioactive event,
can protect the thyroid gland, which is extremely sensitive to
radiation damage. The World Health Organization recommends
that the drug be stockpiled in homes near nuclear power
plants.
A compound called Prussian blue also can be used to treat
people who receive high doses of the radioactive element
cesium, which terrorism experts say could be disseminated in a
dirty bomb. Only one small European firm makes the drug, and
the FDA has asked U.S. companies to apply to manufacture it.
But for now, military officials see the greatest possible
benefit in HE-2100. "We're a long way from having a
product," Zimble said, "but we think we can protect
troops with it."
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