From: c palmer on
Photodynamic drug to go further in trials for treatment of prostate
cancer

May 7, 2006 /source: McGill University, Montreal, Ca./

Early trials of an experimental photosensitizer cancer drug called
Tookad have yielded dramatic results, according to Dr. Mostafa Elhilali,
Chief Surgeon at the McGill University Health Centre (MUHC) and study
principal investigator. In a recently-completed trial, 46 percent of
patients showed no evidence of prostate cancer after treatment with
optimum doses of Tookad and the correct light intensity. A larger study
to determine the drug's efficacy is now underway at the MUHC.

"This new trial is designed to treat patients whose prostate cancers
have recurred despite radiation therapy," explains Dr. Elhilali. "From
previous studies, we have learned optimum light intensity and drug
dosages. Now, we plan to treat patients, using this information to
deliver optimum therapy to all participants. If the trial also shows
beneficial effects, we will go to the next phase - registering the drug
to make it generally available for therapy."
"Results so far are unprecedented," adds Dr. Armen Aprikian, Chief of
Urology at MUHC and study co-investigator.

"However, they are not conclusive. The upcoming trial is so important
because it will give us definitive evidence of how effective Tookad
therapy is. Good results will lead to wider use."

Tookad (from a Hebrew word meaning the warmth of light) is a non-toxic,
light-activated drug derived from chlorophyll. Injected into the
patient, it remains inactive until exposed to laser light. Doctors shine
the laser into the body through a catheter, targeting the tumor using
fiber optics. Once activated, Tookad produces a chemical that blocks
blood vessels in the immediate area and chokes off the tumour's blood
supply.

"The mechanism is local, not systemic," explains Dr. Elhilali. "The drug
is activated only where light is shining, so nearby healthy tissue is
spared. Tookad has another advantage: it is eliminated in two hours.
Previously, we had to keep people in the dark for weeks after treatment
with these types of agents."

MUHC researchers are now recruiting patients with recurring prostate
cancer to participate in phase two trials with Tookad. Candidates should
contact Dr. Elhilali or Dr. Aprikian at the MUHC to learn more, or call
Joanne Savard at 934-1934, extension 34037.

Current Canadian studies of Tookad in recurrent prostate cancer patients
are the first of their kind anywhere. "This is totally new," says Dr.
Aprikian. "It's appropriate that the MUHC, as an internationally
recognized institution, is leading the way in this area."

The McGill University Health Centre (MUHC) is a comprehensive academic
health institution with an international reputation for excellence in
clinical programs, research and teaching. The MUHC is a merger of five
teaching hospitals affiliated with the Faculty of Medicine at McGill
University--the Montreal Children's, Montreal General, Royal Victoria,
and Montreal Neurological Hospitals, as well as the Montreal Chest
Institute. Building on the tradition of medical leadership of the
founding hospitals, the goal of the MUHC is to provide patient care
based on the most advanced knowledge in the health care field, and to
contribute to the development of new knowledge. www.muhc.ca

Sources and links

Selection of earlier Tookad research:
Vascular Targeted Photodynamic Therapy (VTP): A New Modality that Cuts
Off The Tumor Blood Supply Yoram Salomon, Avigor Scherz, et al.,
Weizzman Institute of Science, Rehovot, Israel. Fulltext, .pdf
Studies of a vascular-acting photosensitizer, Pd-bacteriopheophorbide
(Tookad), in normal canine prostate and spontaneous canine prostate
cancer. Huang z, et al. HealthONE Alliance, Denver, Colorado 80203, USA.
Lasers Surg Med. 2005 Jun;36(5):390-7.

"RESULTS: Tookad is a vascular-acting drug and clears rapidly from the
circulation. Tookad-PDT-induced lesions, in both normal and cancerous
prostates, were characterized by marked hemorrhagic necrosis.
CONCLUSIONS: Tookad-PDT is very effective in ablating prostatic tissue
through its vascular effects."

Effects of photodynamic therapy on peripheral nerve: in situ
compound-action potentials study in a canine model. Dole KC et al.
HealthONE, Denver, Colorado 80203, USA; Department of Biomedical
Sciences, Colorado State University, Fort Collins, Colorado 3
NEGMA-LERADS, Toussus-Le-Noble, France. "This canine model adequately
demonstrates effects of Tookad PDT on peripheral nerves. Direct
irradiation of 100-200 J/cm 2 can alter nerve conduction and induce
nerve damage. Therefore, possible side effects of interstitial PDT on
the pelvic plexus need to be investigated in future studies."

Prostate cancer drug may kill other tumours
From the Toronto Star, 2005-06-13
SCOTT ROBERTS, staff reporter. Posted, PSA Rising forums 28 Jul 2005
British Journal of Cancer (2003) 89, 2320-2326.

Selectivity of the photosensitiser Tookad for photodynamic therapy
evaluated in the Syrian golden hamster cheek pouch tumour modelF Borle,
et al. Institute of Environmental Engineering, Swiss Federal Institute
of Technology (EPFL), CH-1015 Lausanne, Switzerland....

Photochemistry and Photobiology: Vol. 78, No. 2, pp. 124–130.

Endobronchial Phototoxicity of WST 09 (Tookad®), a New Fast-Acting
Photosensitizer for Photodynamic Therapy: Preclinical Study in the Pig
Alain Tremblay, et al. Divisions of Respiratory Medicine and Medical
Oncology, University of Calgary, Calgary, Alberta, Canada ....

BOLD contrast MR monitors antivascular photodynamic therapy in lab mice.
By Don Rauf. DiagnosticImaging.com, March 2004

Photodynamic Therapy of Established Prostatic Adenocarcinoma with
TOOKAD: A Biphasic Apparent Diffusion Coefficient Change as Potential
Early MRI Response Marker Authors: Plaks V. ; Koudinova N. ; Nevo U.
; Pinthus J.H. ; Kanety H. ; Eshhar Z.; Ramon J. ; Scherz A. 7
; Neeman M. ; Salomon Y. Source: Neoplasia , Volume 6, Number 3,
May/June 2004, pp. 224-233(10)

Other types of photodynamic therapy for cancer
Europe: biolitec pharma's Foscan®
Foscan® is a photosensitizing agent (a light-sensitive drug), which
contains temoporfin and is used in photodynamic therapy (PDT). In
October 2001, Foscan® was approved in the European Union, Norway &
Iceland as a local therapy for the palliative treatment of patients with
advanced head and neck cancer who have failed prior therapies and are
unsuitable for radiotherapy, surgery or systemic chemotherapy. More at
biolitecpharma.com

USA & Canada

In the USA to date, the Food and Drug Administration (FDA) has approved
the photosensitizing agent called porfimer sodium , or Photofrin®, for
use in PDT to treat or relieve the symptoms of esophageal cancer and
non-small cell lung cancer (7). Porfimer sodium is approved to relieve
symptoms of esophageal cancer when the cancer obstructs the esophagus or
when the cancer cannot be satisfactorily treated with laser therapy
alone. Porfimer sodium is used to treat non-small cell lung cancer in
patients for whom the usual treatments are not appropriate, and to
relieve symptoms in patients with non-small cell lung cancer that
obstructs the airways. In 2003, the FDA approved porfimer sodium for the
treatment of precancerous lesions in patients with Barrett's esophagus
(a condition that can lead to esophageal cancer).


knowledge is power - growing old is mandatory - growing wise is optional
"Many more men die with prostate cancer than of it. Growing old is
invariably fatal. Prostate cancer is only sometimes so."
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