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Diet Drugs
Summary & Comment
Obesity costs
America a staggering $100+ billion in health care costs and weight-loss products
and programs, according to the U.S. Surgeon General. And as the rate of obesity
in America is growing, there has been a fundamental shift in how obesity is
viewed-as a disease rather than simply poor lifestyle habits.
"Obesity used to be viewed as a
lack of willpower in a patient... It was not viewed as a medical problem. Today
I think it is.", according to Douglas Greene at the University of Michigan. The
bottom line is that a growing consensus holds that the traditional approach to
weight-loss - diet and exercise - is futile for the majority of people.
The market for prescription
diet drugs has been bumpy, characterized by major product withdrawals, some
nasty side effects, and moderate weight loss. The “magic pill” everyone is
hoping for is still not here. Only two drugs (orlistat and sibutramine) have
been approved for the long-term treatment of obesity.
Representatives of the
pharmaceutical industry estimate that slightly more than two dozen obesity drugs
are currently undergoing clinical trials. Meanwhile, another 32 experimental
medications are in early-stage development, and six existing drugs approved for
diabetes are being cross-tested for their effectiveness at reducing weight in
overweight patients.
Currently there are more than a
dozen new drugs for treating obesity either in or about to begin human clinical
trials and there are 5 new drugs in clinical trials for diabetes, which may also
produce weight loss. In addition, there are also at least 20 other drugs which
impact feeding, appetite, metabolic rate, or weight regulation that are in
pre-clinical or animal testing.
When will these drugs be
released? FDA guidelines for phase 3 trials for drugs for obesity call for at
least one year on therapy and at least one more year of follow-up. In theory, a
weight loss drug with successful phase 3 trials could be approved in a little
over two years after the initiation of phase 3 trials. In practice, it generally
takes longer than two years. The likelihood is that not all of these drugs will
make it to the market.
We may be entering a new era of
"lifestyle drugs" aimed at tackling such things as: hair loss, aging skin,
weight gain—all the lifestyle issues of the baby boomers. As a recent
Business Week article pointed out, "At a time when people lay out $20 or $30
a month on cable TV, it seems likely they’ll pay as much for a lifestyle drug."…
"Hundreds of millions of dollars are being poured into efforts to discover safe
and effective treatments for obesity, anxiety, memory loss, depression,
incontinence, and arthritis."
However, there is no guarantee
that the new drugs being developed will work long-term, and the FDA is likely to
set high standards for approval. Questions remain as to how long studies must
last and what amount of weight loss is optimal. Some FDA advisers want the drugs
to also reduce the incidence of such obesity-related problems as diabetes or
hypertension. And, because obesity isn’t directly life-threatening like AIDS or
cancer, the risk of taking a drug over the long term is weighed carefully
against the benefit of weight loss.
In 1997, bariatricians and
other doctors were swamped with demand from their patients for prescription diet
medications. The ranks of the American Society of Bariatric Physicians (ASBP)
tripled to record levels and prescriptions for the two drugs approved for use,
the "fen/phen" combination, skyrocketed. "Fen/phen" refers to the combination
of: Fenfluramine, and
Phentermine.
Phentermine
is sold under 18 different brand names. The most commonly used are:
Phentermine, Fastin, Pondimin, Adipex-P, and Ionamin. Others include: Anorexin,
Bacarate, Bontril, Melfiat, Obenil, Plegine, Preludin, Pre-State, Sanorex,
Statobex, Tenuate, Tepanil, Trimtabs, and Voranil.
Finding a profitable drug will
require some luck. Researchers believe obesity results from a number of genetic
and environmental factors. The hope is that doctors will one day have a variety
of drugs to customize treatment of overweight persons.
Many doctors believed that
these newly popular drugs, used in combination, would work better than any diet
drugs still on the market (i.e.
diethylpropion and mazindol), and that it represents a long-overdue change
in the way the medical profession views weight control. Many doctors believe
that medication may be the best way to correct a serotonin imbalance. Others,
however, think it just exposes patients to more potential side effects, or that
overuse or abuse may become a problem.
These medications generally
work best when combined with exercise programs, and are found to be least
effective when overeating takes place mainly for psychological reasons
(depression, stress, loneliness).
Some obesity experts fear the
Redux scare will cause long-term damage to the notion of treating obesity with
drugs. Also potentially hurt are the prospects of new diet drugs, working
differently, that await FDA approval or are in late stage clinical trials, and
in the development of new agents." Personnel at the American Society of
Bariatric Physicians (obesity specialist physicians) are afraid the problems are
going to cause a setback in the approval of new agents.
It appears that the FDA may be
moving toward easier approval of obesity drugs. A draft proposal indicates that
human trials required for the drugs’ approval may be shorter and won’t have to
show as many benefits as earlier-proposed guidelines. If the FDA approves the
changes, a new generation of anti-obesity prescription drugs are more likely to
reach the market over the next several years. Before dexfenfluramine, the agency
had not approved one since the 1970s.
Pharmaceutical firms say that
the new anti-obesity drugs should only be used along with strict programs of
exercise and diet. However, we all saw how fast Redux caught fire with dieters
who merely wanted to lose a few cosmetic pounds. The discovery of a flawed fat
gene is no excuse to junk the treadmill and toss out the calorie counters. That
was the unanimous message from nutritionists, fitness experts and diet coaches.
It would be simplistic to say
that currently-used diet medications, and future ones under development through
the early part of this century, will render obsolete commercial weight loss
programs and other commonly used over-the-counter do-it-yourself products. Not
everyone will be able to afford the ongoing costs. Not everyone will be
candidates for such treatment. Some of the therapies may include taking
injections, a turn-off for the squeamish. Others may prefer a more "natural"
approach to weight management - proper diet and more exercise.
The role of many physicians in
weight management is also suspect. Traditionally, doctors have not had the time
to counsel their patients in depth about smoking cessation or losing weight.
And, the psychological/emotional issues related to obesity are crucial. Will
doctors that don’t specialize in treating obesity (i.e. general practitioners,
etc.), increasingly squeezed by managed care and growing caseloads under HMOs,
have the time to motivate, cajole, counsel and offer the peer support that
commercial weight loss organizations such as Weight Watchers, Jenny Craig, or
eDiets.com offer? BestDietForMe.com/Marketdata analysts don't think so.
Prescribing diet drugs can
become a "cash cow" for many doctors whose incomes have been squeezed by managed
care. The "diet industry" sometimes also attracts doctors with troubled pasts.
Penalties for dispensing bad weight loss counseling are rare and minor. They may
keep physicians out of insurance plans, but that doesn’t matter much in weight
loss and other optional medical services, since insurance rarely covers diet
plans and patients pay their doctors "out-of-pocket".
Leptin
Preliminary results from early
studies on the use of daily injections of genetically engineered leptin are
reporting weight loss among some genetically obese subjects. Higher doses may be
needed for higher weights. The most common side effects were pain at the
injection site and headache. There appear to be no significant adverse effects
on major organs, including the heart, liver, kidney, central nervous system, or
gastrointestinal tract. It also does not appear to affect insulin levels, a
previous concern.
According to the Wall Street
Journal, Genomics-based obesity drugs are being tested in human trials.
After years of analyzing the human genome, scientists at Millennium
Pharmaceuticals say they have finally found a gem; an obesity drug that works by
changing metabolism.
Traditionally, obesity drugs
have been appetite suppressants, which often come with severe side effects. The
new drug, co-developed with Abbott Laboratories of North Chicago, is part of a
new class of medications that seek to alter metabolism.
Known by the name MLN4760, the
drug is based on the discovery of a gene that provides instructions for the
production of an enzyme that scientists believe helps prompt the body to store
fat. The drug doesn’t act directly on the gene, but rather inhibits the enzyme’s
action- theoretically prompting the body to burn fat, rather than store it. It
is still too early to tell if the drug will be a success. Most early-stage drugs
in fact fail.
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