More patients, and some more safety info, but no new efficacy data disclosed yet:
Headline: Pharmacyclics' ANTRIN(TM) Photoangioplasty Trial Demonstrates
Activity
In Atherosclerosis
======================================================================
Interim Phase I Data Presented at Society of Cardiovascular Interventional
Radiology Meeting
SUNNYVALE, Calif., March 22 /PRNewswire/ -- Pharmacyclics, Inc.
(NASDAQ:PCYC) announced that interim results from the drug dose escalation
portion of its phase I study with ANTRIN(TM) photoangioplasty (ANTRIN PA)
for
patients with atherosclerotic peripheral arterial disease were reported
yesterday at the meeting of the Society of Cardiovascular Interventional
Radiology (SCVIR) in Orlando, Florida.
The phase I trial is intended to primarily evaluate safety of ANTRIN PA
in
patients with symptomatic arterial insufficiency involving the major
arteries
of the lower extremities. The drug and light dose-escalation study is
designed to first evaluate the safety of ANTRIN PA using increasing doses of
ANTRIN in successive cohorts of patients. Enrollment in the drug
dose-escalation portion of the study has been completed. A single
intravenous
injection of ANTRIN was given and followed by treatment with light delivered
to the diseased area through a 0.89mm optical fiber placed using standard
percutaneous endovascular techniques. Patients were evaluated for toxicity
and local arterial responses by follow-up angiograms and intravascular
ultrasound (IVUS) performed either 14 days or 28 days following
photoangioplasty. In the ongoing second portion of the study, treatment
with
increasing doses of light is being evaluated.
The drug dose escalation portion of the study was conducted at Stanford
University Medical Center. Sixteen patients were treated and evaluated with
IVUS and/or angiograms in the study reported by Mahmood Razavi, M.D., a
cardiovascular interventional radiologist at Stanford. In the 14 patients
receiving follow-up IVUS, 12 responded to treatment, defined as an increase
of
greater than 10% in the blood vessel opening or minimal luminal diameter
(MLD). Responding patients had increases in MLD up to 76% with a mean of
35%.
All 16 patients received follow-up angiograms, of which 7 demonstrated a
reduction in stenosis in the treated lesions.
Five increasing ANTRIN doses were studied and no serious
treatment-related
adverse reactions or vascular toxicities were seen. At the higher doses,
some
patients reported mild and transient tingling sensations in the tips of
their
fingers, thought to be associated with exposure to sunlight.
"Finding evidence of reproducible plaque reduction in severe
atherosclerosis involving peripheral arteries is very impressive,
particularly
in a phase I study," stated Dr. Razavi. "The limits have been reached for
mechanical treatments of atherosclerosis, such as balloon angioplasty.
ANTRIN
photoangioplasty is a promising new technique that offers potential
advantages
over existing techniques."
In the second portion of the study, now being conducted at both the
Mid-America Heart Institute in Kansas City, Missouri and Stanford, ANTRIN PA
is being evaluated for safety and activity using increasing doses of light.
At the SCVIR presentation, 17 additional patients were reported to have been
treated with ANTRIN PA using the higher doses of light. No toxicity was
observed in these patients and follow-up data is pending. The entire study
is
expected to enroll about 50 patients and should be completed in April.
"We continue to be very excited by the results of our ANTRIN
photoangioplasty trials," stated Richard A. Miller, M.D., president and CEO
of
Pharmacyclics. "Completion of the second portion of the study should
provide
us with the optimum drug and light dose for phase II trials in patients with
peripheral artery disease and will also be useful for our planned trials in
patients with coronary artery disease."
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 blood. This property
enables the treatment of atherosclerosis or restenosis without interruption
of
blood flow. Once localized in the diseased vessel, ANTRIN can be activated
by
endovascularly-delivered light using an optical fiber inserted into the
vessel. In contrast to mechanical procedures such as balloon angioplasty,
ANTRIN photoangioplasty appears to reduce atherosclerosis without damaging
the
endothelium or the vessel wall, both important factors leading to
restenosis.
Long segments of diseased vessels may be treated, which is a potential
advantage over existing angioplasty techniques that are limited to the
treatment of relatively short segments.
Atherosclerosis results from the accumulation of cholesterol,
macrophages
and smooth muscle cells in the walls of blood vessels. This often results
in
narrowing of the lumen and reduction of blood flow. 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. In the
peripheral circulation (arteries supplying blood to the legs),
atherosclerosis
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. In the U.S. there are
approximately 600,000 coronary angioplasty procedures performed annually and
another 150,000 such procedures performed in the lower extremities.
Angioplasty is complicated by the development of restenosis (a renarrowing
of
blood vessels after the initial treatment) 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.
IVUS is a procedure used to evaluate the inside of arteries and is
performed by inserting an ultrasound transducer within the lumen of the
blood
vessel. Using this diagnostic technique, it is possible to measure the size
of the lumen or the degree of obstruction within a vessel. IVUS can also be
used to evaluate the characteristics of the blood vessel wall. It is
commonly
used to assess atherosclerosis and response to therapeutic interventions.
Angiograms are performed by injecting X-ray contrast media into blood
vessels
and are also used to evaluate abnormalities of blood vessels. Generally,
angiograms are less sensitive and less quantitative than IVUS.
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, atherosclerotic
cardiovascular disease and diseases of the retina. The company's products
are
ring-shaped small 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: Pharmacyclics(R), the "pentadentate" logo(R) and ANTRIN(TM) are
trademarks of Pharmacyclics, Inc.
SOURCE Pharmacyclics, Inc.
-0- 03/22/99
/CONTACT: Leiv Lea of Pharmacyclics, Inc., 408-774-0330; or Angela M.
Bitting of Russell-Welsh, Inc., 650-312-0700, ext. 15, for Pharmacyclics,
Inc./
/Company News On-Call: prnewswire.com or
fax,
800-758-5804, ext. 110031/
/Web site: pcyc.com
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