| Cancer Vaccines from Cuba
The US federal government is permitting CancerVax to license three
experimental cancer drugs from Cuba, �a country that some industry executives
and scientists say is surprisingly strong in biotechnology for a developing
nation,� writes Andrew Pollack in the New York Times. Cuba has
established research institutes staffed by Cuban scientists, many educated in
Europe. The US State Department said that the exception to the strict trade
embargo with Cuba had been made because of the revolutionary life-saving
potential of the experimental Cuban drugs.
Cuba already sells some biotechnology drugs, including a hepatitis B vaccine
and streptokinase for heart attacks, in countries other than the United States,
and a Cuban vaccine for meningitis B licensed by GlaxoSmithKline in 1999 is in
clinical trials. In addition, an American company is reported to have been
allowed to license a drug called PPG used to lower cholesterol but which also is
�the Cuban equivalent of Viagra.�
CancerVax’s own melanoma vaccine has been in development for 40 years and is
only now in the final phase of clinical trials. The first of the three
experimental so-called cancer vaccines from Cuba has already shown some promise
in small trials and could reach the market in 2008 or 2009.
It targets epidermal growth factor (EGF), but unlike ImClone�s
Erbitux, which blocks the EGF receptor on cancer cells, it links the
growth factor to a bacterial protein injected into the body which (in theory)
stimulates the immune system to make antibodies that attack the growth factor.
In small clinical trials outside the United States, patients with advanced
lung cancer who got the vaccine lived longer than those who did not receive the
treatment, and phase 2 trials are now being planned. The second drug, not yet in
clinical trials, is a similar vaccine aimed at transforming growth factor-alpha,
another protein that can stimulate cancer cell growth by binding to the EGF
receptor. The third, also not in clinical trials, is aimed at stimulating
antibodies to the receptor.
Reference: Pollack, Andrew (2004). “U.S.
Permits 3 Cancer Drugs From Cuba.” New York Times, July 15.
Pancreatic Cancer “Vaccine”
Therion Biologics� PANVAC-VF metastatic pancreatic cancer vaccine, a smallpox
relative, is in Phase III clinical trials in the US. It is being tested in
patients who have not responded to treatment with the most effective drug
gemcitabine, and works by stimulating the immune system to target and destroy
two proteins found in more than 90 percent of pancreatic tumor cells.
Unlike a traditional vaccine, it does not prevent cancer but destroys one if
it finds one. One trial patient�s wife said something we think is significant:
“We know it’s not a cure, but if we could get five years, maybe there will be a
cure around then.” The significance is that cancer patients and their families
are growing increasingly aware of the advances in the war on cancer and
increasingly expectant of the war�s imminent end.
Reference: Jarvis, Jan (2004). “Texan
first in U.S. to try pancreatic cancer vaccine.” Fort Worth Star-Telegram,
June 30.
Long-term Heart Study Too Long?
A clinical trial is underway to find out whether medicines and certain types
of heart surgery could help people with heart failure and blocked coronary
arteries. The trial, called Stich (surgical treatments for ischemic heart
failure), will follow 2,800 patients at 90 heart centers around the world for
seven years. Among the therapies being assessed are bypass surgery to improve
blood flow to the heart muscle, and cutting open the heart to reshape it and
remove scar tissue in order to help it pump more efficiently. Different groups
of study participants will receive different treatment mixes, in order to gather
evidence (currently lacking) to scientifically determine which treatments and
combinations of treatments are most effective.
Reference: Grady, Denise (2004). “Last Resports:
Putting a Weakened Heart in Experimental Hands.” New York Times, July 19.
Light at the End of the Artery
Guidant Corp. will invest up to $7 million in Miravant Medical Technologies,
to jointly develop Miravant�s light-activated drugs to prevent heart attacks. In
tests on cell cultures and in animals, the therapy has shown promise in treating
the �vulnerable plaque� now thought to cause the vast majority of heart attacks,
writes J.K. Wall in the Indianapolis Star. It would be hard to improve on
Wall�s concise description of the therapy, so here it is in full:
�Cholesterol and other substances build up in the artery walls, forming
lesions. Some lesions have thin caps that can become inflamed and rupture. When
they burst, the blood in the artery clots, which blocks flow and can cause a
heart attack. Miravant’s therapy injects a drug into the bloodstream that
absorbs a specific wavelength of light. A light-emitting catheter is inserted
into the artery. The drug turns the light energy into chemical energy. That
chemical energy then alters the atmosphere around a lesion so the cells of the
lesion switch into apoptosis, a natural process of cell death.�
Guidant’s contribution will be its experience in clinical tests and
regulatory procedures, as well as its business perspectives on vulnerable
plaque. In 2002, Guidant reported encouraging results from a new imaging
technology to detect arterial plaque.
Reference: Wall, J.K. (2004). “Guidant invests
in heart research: Stake nets link with firm’s light therapy for plaque.”
Indianapolis Star, July 7.
New Uses for Old Drugs
Laboratory and animal studies have shown that the anemia drug erythropoietin
(EPO; sold as Epogen, Aranesp, Procrit, and Eprex)
also acts to protect cells and tissues in the central nervous system from damage
and death, making it potentially useful as a treatment for strokes, spinal cord
injuries, multiple sclerosis, and many other ailments, writes Andrew Pollack in
the New York Times.
One small clinical trial in Germany found that EPO administered within eight
hours of a stroke helped protect the brain from damage and improved patient
recovery. Another is testing EPO as a treatment for schizophrenia. US trials are
being planned for AIDS-related dementia and for a nerve disease similar to
multiple sclerosis.
New York biotech firm Warren Pharmaceuticals says it has developed a
chemically modified version of EPO that does not increase red blood cell levels
but, in animals, still protects tissues from damage, thus avoiding the major
risk attendant upon using EPO to treat people who are not anemic, whose red
blood cell levels might otherwise be increased to dangerously high levels,
causing the blood to thicken and posing a risk that life-threatening clots would
form.
One researcher who is independently working on ways to deliver EPO to the
brain in a way that would minimize its effects on red blood cells said it would
be faster to use EPO itself rather than wait for trials and approval of Warren�s
modified version, as it is already on the market and has been proved basically
safe, especially if used in combination with IGF-1 (insulinlike growth
factor-1), which allows a smaller EPO dosage. A clinical trial of that method is
planned for the dementia that sometimes accompanies HIV infection. �People
infected with that virus tend to be anemic, so any increase in their red cell
counts would not be a problem, he said,� reports Pollack.
A neurologist at Johns Hopkins, impressed with EPO�s neuro-protective
properties, hopes to begin a trial this year using EPO to treat transverse
myelitis, an inflammatory disease of the spinal cord that resembles multiple
sclerosis, and possibly to treat nerve damage in the limbs.
Even after regulatory approval, there may remain some thorny patent issues to
be worked out before any of these modified EOP therapies can be sold.
Reference: Pollack, Andrew (2004). “Studies Find
Biotechnology Anemia Drug Shows Promise in Treating Several Diseases.” New
York Times, July 9.
Robot Knee Surgeon
Integrated Surgical Systems hopes to receive US Food and Drug Administration
approval for its Robodoc hip-and-knee implant robots by next summer,
reports Celia Lamb in the Sacramento Business Journal. The robots are
already approved and in use in Europe and Asia.
Robodoc was first introduced in 1992. The company has finished 100
surgeries of 188 required by the FDA and expects to enroll the remaining
patients by the end of this year. Robodoc sells for $500,000 to $1 million,
depending on the specific application. One surgeon said it enabled more precise
preparation of the bone to receive the implant, but was slow and difficult, and
surgeons might not rush to buy it. Its maker says the robot�s precision reduces
the risk of surgical complications and resulting lawsuits, ultimately cutting
costs for patients and doctors.
Reference: Lamb, Celia (2004). “Surgical
robot crawls through FDA process.” Sacramento Business Journal, July 19.
Stem Cell Therapy Doesn’t Need Stem Cells
A US National Institutes of Health-funded study conducted at Oregon Health
& Science University�s Oregon Stem Cell Center casts doubt on the accepted
wisdom that stem cells repair diseased tissue by transforming into other cell
types. The study found that mature macrophages derived from bone marrow stem
cells, and not bone marrow stem cells themselves, are what fuse with diseased
liver cells, ultimately curing a genetic liver disease. “The most important
discovery is you don’t need to transplant stem cells at all,” said a study
co-author “If you transplant only macrophages, you’ll get liver cells that
correct liver disease in mice.”
The study’s lead author called fusion between macrophages and hepatocytes,
the cells in the liver that provide the typical functions of this organ, “a rare
physiological, but potentially therapeutically exploitable, phenomenon.”
Macrophages comprise a substantial and beneficial fraction of the liver cells,
helping to resolve inflammation, remove debris, and produce factors that help
the liver to function. �In addition, they provide a link between the bone marrow
compartment and highly specified organ cells, and this is new and exciting
because of therapeutic implications,” he said.
In 2000, the same researchers showed that hematopoietic stem cells —
blood-forming stem cells derived from bone marrow — can cure liver disease in
mice, but through cell fusion rather than differentiation of the transplanted
stem cells. In cell fusion, two distinct cells meld to form a single, new cell.
�The liver cells were turning the blood cells into their own kind.”
In the latest study, macrophages derived from bone marrow stem cells were
transplanted into the spleens of mice with the genetic liver disease
fumarylacetoacetate hydrolase deficiency, also called hereditary tyrosinemia in
humans. The spleen slowly releases the macrophages into the liver. The result
was “robust production” of functional hepatocytes. Unlike bone marrow stem cell
transplantation, macrophage transplantation does not require �lethal doses of
preparative irradiation, which has severe side effects.�
Macrophages also can more easily be grown in tissue culture than stem cells,
and future studies will even look at whether they can be genetically modified
before transplantation. “That’s the future. That’s what we’re trying to do,” he
said.
Reference: Unknown (2004). “Macrophages,
Not Stem Cells, Correct Liver Disease By Fusion.” Oregon Health &
Science University via Science Daily, July 12.
Virtual Therapy
ABC News reports on several technology applications are being developed by
therapists and computer programmers. They include:
- Computer-enhanced �virtual� psychotherapy sessions that allow patients and
therapists to interact by adopting computer animated characters to represent
themselves.
- Virtual reality technology to help patients overcome phobias, anxieties, and
addictions; for which some therapists claim a success rate of more than 90
percent.
- Virtual guided group therapy sessions with specialists at another location.
- Software to animate psychotic patients’ hallucinations and thereby enable
therapists to assemble virtual hallucinations from a library of
three-dimensional elements drawn from previous patient interviews.
- Artificially intelligent digital humans to perform role playing exercises
with therapists in training.
Critics say that allowing patients to “hide” behind computer generated images
could “promote the fiction” that therapeutic change can be accomplished without
effort and endurance; and that the therapeutic effects of computer generated
interactions do not yet “measure up” to counseling with humans.
Reference: Unknown (2004). “ABCNews
Reports on Virtual Counseling.” iHealthBeat, July 07. |
