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Subject: Pharmacyclics' ANTRIN(TM) Photoangioplasty Data Presented at American Society For Photobiology Meeting
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Preliminary Phase I Data Demonstrate Activity in Atherosclerosis
SUNNYVALE, Calif., July 15 /PRNewswire/ -- Pharmacyclics, Inc.
(NASDAQ:PCYC) today announced that two presentations on ANTRIN(TM)
photoangioplasty were delivered at a symposium on Phototherapy in Cardiology
at the meeting of the American Society of Photobiology (ASP) in Snowbird,
Utah.
Stan Rockson, M.D., a cardiologist from Stanford University Medical
Center, presented preliminary results from a phase I dose escalation study in
fourteen patients with peripheral arterial disease. This study is primarily
designed to evaluate safety and feasibility of ANTRIN photoangioplasty.
Patients with lower extremity arterial insufficiency were entered and received
a single intravenous injection of ANTRIN followed 24 hours later by
endovascular delivery of light using an optical fiber catheter. Patients were
evaluated for systemic toxicity and for local arterial effects by follow-up
angiograms and intravascular ultrasound. Various dose levels of ANTRIN have
been evaluated to date and no serious treatment-related adverse reactions or
vascular toxicity have been noted. Dr. Rockson reported having demonstrated
the ability to increase lumen size and reduce atherosclerotic plaque after
ANTRIN photoangioplasty at the dose level recently achieved. Based on the
results, the investigators are expanding the study to include patients with
disease in the iliac and deep femoral arteries.
"We are encouraged by these early findings and the demonstration of
activity," said Dr. Rockson. "ANTRIN photoangioplasty may represent a novel
approach to the treatment of atherosclerosis and restenosis with the potential
to enhance the efficacy of existing endovascular procedures."
In another presentation, Moto Hayase, M.D., a cardiologist from Stanford
University Medical Center, presented data from animal models of
atherosclerosis and restenosis. Dr. Hayase showed that administration of
ANTRIN followed by light delivered by an optical fiber catheter introduced
inside the vessel resulted in substantial reduction of atherosclerotic plaque.
In a restenosis model, reduction of disease and improvement in lumen size was
observed following ANTRIN photoangioplasty. In some of the studies presented,
ANTRIN was delivered intra-arterially, directly to the diseased site. This
resulted in the deposition of high concentrations of the drug in the plaque
with minimal amounts of the drug being deposited in other areas of the body.
The investigators demonstrated that ANTRIN photoangioplasty caused dramatic
reduction in infiltrating macrophages in the lesions. Macrophages are
increasingly noted to be critical to the formation of atheroma and restenosis.
"We are excited with the progress of our ANTRIN photoangioplasty
pre-clinical and clinical studies," said Richard A. Miller, M.D., president
and CEO of Pharmacyclics. "The pre-clinical and early clinical results will
lead us to expand our studies into the treatment of both atherosclerosis and
restenosis."
ANTRIN is a water-soluble photosensitizer that accumulates in
atherosclerosis, is cleared rapidly from the blood and is activated by 732nm
light, a wavelength that is able to penetrate through tissue and blood. This
property enables the treatment of atherosclerosis or restenosis without
interruption of blood flow. Once localized in the diseased vessel, ANTRIN may
be activated by endovascularly-delivered light using an optical fiber inserted
in the vessel.
In animal studies, ANTRIN photoangioplasty appears to reduce
atherosclerosis without damaging the endothelium and without damaging the
vessel wall, both important factors leading to restenosis. Long segments of
diseased vessels may be treated; a potential advantage over balloon
angioplasty which is useful only for treating relatively short segments.
Atherosclerosis results from the accumulation of cholesterol, macrophages
and smooth muscle cells in the walls of blood vessels. This may result in
narrowing of the lumen and reduction of blood flow. Recent research indicates
that macrophages are responsible for eliciting the disease by scavenging
low-density lipoproteins. In the coronary arteries (arteries that supply the
heart with blood) atherosclerosis can result in angina or heart attacks. In
the cerebrovascular circulation (arteries supplying blood to the brain)
atherosclerosis may result in stroke, and in the peripheral circulation it may
result in ischemia leading to decreased function and ultimately loss of limbs.
Currently, atherosclerosis is treated with medical therapy, surgery or
endovascular procedures such as balloon angioplasty. There are approximately
600,000 coronary angioplasty procedures performed annually in the U.S. and
another 150,000 such procedures performed in the lower extremities.
Angioplasty is complicated by the development of restenosis, or the
renarrowing of blood vessels, in a significant number of patients, which has
led to the widespread use of stents. Although stents are effective in opening
the vessel, this procedure has only partially addressed the problem.
Pharmacyclics is a pharmaceutical company developing energy-potentiating
drugs to improve radiation therapy and chemotherapy of cancer, and to enable
or improve the photodynamic therapy of certain cancers and atherosclerotic
cardiovascular disease. The company's products are small ring-shaped
molecules, called "texaphyrins," which are patented agents derived from
Pharmacyclics' versatile technology platform for designing and synthesizing
energy-potentiating drugs. These texaphyrins localize in cancer cells and
atherosclerotic plaque, where they can be activated by forms of energy,
including X-ray, chemical and light, to eliminate diseased tissue.
The statements made in this press release may contain certain
forward-looking statements that involve a number of risks and uncertainties.
Actual events or results may differ from the company's expectations. In
addition to the matters described in this release, future actions by the U.S.
Food and Drug Administration and other domestic and foreign regulatory
agencies, the initiation, timing and results of pending or future clinical
trials, as well as risk factors listed from time to time in the company's
reports as filed with the U.S. Securities and Exchange Commission, including
but not limited to, its reports on Forms 10-Q and 10-K, may affect the actual
results achieved by the company.
NOTE: ANTRIN is a trademark of Pharmacyclics, Inc. The symposium, an
official part of the ASP meeting, consisted of six presentations on the
applications of phototherapy in cardiovascular medicine. Pharmacyclics is a
sponsor of the symposium.
SOURCE Pharmacyclics, Inc.
-0- 07/15/98
/CONTACT: Leiv Lea of Pharmacyclics, Inc., 408-774-0330; or Angela
Bitting of Russell-Welsh, Inc. 650-312-0700, ext. 15, for Pharmacyclics/
/Company News On-Call: prnewswire.com or fax, 800-758-5804,
ext. 110031/
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