SAN
FRANCISCO (AP) -- A quarter-century after the U.S. Food and Drug Administration
approved the first prescription drugs based on the main psychoactive ingredient
in marijuana, additional medicines derived from or inspired by the cannabis
plant itself could soon be making their way to pharmacy shelves, according to
drug companies, small biotech firms and university scientists.
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(AP Photo/ GW Pharmaceuticals)
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A British
company, GW Pharma, is in advanced clinical trials for the world's first
pharmaceutical developed from raw marijuana instead of synthetic equivalents- a
mouth spray it hopes to market in the U.S. as a treatment for cancer pain. And
it hopes to see FDA approval by the end of 2013.
Sativex
contains marijuana's two best known components - delta 9-THC and cannabidiol -
and already has been approved in Canada, New Zealand and eight European
countries for a different usage, relieving muscle spasms associated with
multiple sclerosis.
FDA
approval would represent an important milestone in the nation's often uneasy
relationship with marijuana, which 16 states and the District of Columbia
already allow residents to use legally with doctors' recommendations. The U.S.
Drug Enforcement Administration categorizes pot as a dangerous drug with no
medical value, but the availability of a chemically similar prescription drug
could increase pressure on the federal government to revisit its position and
encourage other drug companies to follow in GW Pharma's footsteps.
"There
is a real disconnect between what the public seems to be demanding and what the
states have pushed for and what the market is providing," said Aron
Lichtman, a Virginia Commonwealth University pharmacology professor and
president of the International Cannabinoid Research Society. "It seems to
me a company with a great deal of vision would say, `If there is this demand
and need, we could develop a drug that will help people and we will make a lot
of money.'"
Possessing
marijuana still is illegal in the United Kingdom, but about a decade ago GW
Pharma's founder, Dr. Geoffrey Guy, received permission to grow it to develop a
prescription drug. Guy proposed the idea at a scientific conference that heard
anecdotal evidence that pot provides relief to multiple sclerosis patients, and
the British government welcomed it as a potential way "to draw a clear
line between recreational and medicinal use," company spokesman Mark
Rogerson said.
In addition
to exploring new applications for Sativex, the company is developing drugs with
different cannabis formulations.
"We
were the first ones to charge forward and a lot of people were watching to see
what happened to us," Rogerson said. "I think we are clearly past
that stage."
In 1985,
the FDA approved two drug capsules containing synthetic THC, Marinol and
Cesamet, to ease side-effects of chemotherapy in cancer patients. The agency
eventually allowed Marinol to be prescribed to stimulate the appetites of AIDS
patients. The drug's patent expired last year, and other U.S. companies have
been developing formulations that could be administered through dissolving
pills, creams and skin patches and perhaps be used for other ailments.
Doctors and
multiple sclerosis patients are cautiously optimistic about Sativex. The
National Multiple Sclerosis Society has not endorsed marijuana use by patients,
but the organization is sponsoring a study by a University of California, Davis
neurologist to determine how smoking marijuana compares to Marinol in
addressing painful muscle spasms.
"The
cannabinoids and marijuana will, eventually, likely be part of the clinician's
armamentarium, if they are shown to be clinically beneficial," said
Timothy Coetzee, the society's chief research officer. "The big unknown in
my mind is whether they are clearly beneficial."
Opponents
and supporters of crude marijuana's effectiveness generally agree that more
research is needed. And marijuana advocates fear that the government will use
any new prescription products to justify a continued prohibition on marijuana
use. .
"To
the extent that companies can produce effective medication that utilizes the
components of the plant, that's great. But that should not be the exclusive
access for people who want to be able to use medical marijuana," Americans
for Safe Access spokesman Kris Hermes said. "That's the race against time,
in terms of how quickly can we put pressure on the federal government to
recognize the plant has medical use versus the government coming out with the
magic bullet pharmaceutical pill."
Interest in
new and better marijuana-based medicines has been building since the discovery
in the late 1980s and 1990s that mammals have receptors in their central
nervous systems, several organs and immune systems for the chemicals in
botanical cannabis and that their bodies also produce natural cannabinoids that
work on the same receptors.
One of the
first drugs to build on those breakthroughs was an anti-obesity medication that
blocked the same chemical receptors that trigger the munchies in pot smokers.
Under the name Acomplia, it was approved throughout Europe and heralded as a
possible new treatment for smoking cessation and metabolic disorders that can
lead to heart attacks.
The FDA was
reviewing its safety as a diet drug when follow-up studies showed that people
taking the drug were at heightened risk of suicide and other psychiatric disorders.
French manufacturer Sanofi-Aventis, pulled it from the market in late 2008.
Given that
drug companies already were reluctant "to touch anything that is THC-like
with a 10-foot- pole," the setback had a chilling effect on cannabinoid
drug development, according to Lichtman.
"Big
companies like Merck and Pfizer were developing their own versions (of
Acomplia), so all of those programs they spent millions and millions on just
went away..." he said.
But
scientists and drug companies that are exploring pot's promise predict the path
will ultimately be successful, if long and littered with setbacks.
One is
Alexandros Makriyannis, director of the Center for Drug Discovery at
Northeastern University and founder of a small Boston company that hopes to market
synthetic pain products that are chemically unrelated to marijuana, but work
similarly on the body or inhibit the cannabinoid receptors. He also has been
working on a compound that functions like the failed Acomplia but without the
depressive effects.
"I
think within five to 10 years, we should get something," Makriyannis said.
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