Mexico approves Weizmann prostate cancer treatment

There are not many other successful drugs against early-stage prostate cancer.

Weizmann Institute of Science (photo credit: MICHAEL JACOBSON/WIKIMEDIA COMMONS)
Weizmann Institute of Science
(photo credit: MICHAEL JACOBSON/WIKIMEDIA COMMONS)
Mexico’s Cofepris health authority has authorized the use of an early-stage prostate cancer drug and laser therapy developed by the Weizmann Institute of Science in Rehovot in collaboration with Luxembourg’s Steba Biotech.
A successful Phase III clinical trial in Mexico, Peru and Panama of the treatment called TOOKAD Solublem, involved 80 patients. The results confirmed a high rate of local cures and minimal side effects already reported in Phase II trials.
Negative biopsies and maintenance of patients’ potency, continence and overall quality of life were evidence of the high success rate. There are not many other successful drugs against early-stage prostate cancer.
The approved therapy follows a new paradigm developed by Weizmann Prof. Yoram Salomon of the biological regulation department and Prof. Avigdor Scherz of the plant and environmental sciences department, in the framework of photodynamic therapy.
The Israeli-invented drug was first synthesized in Scherz’s lab from bacteriochlorophyll, the photosynthetic pigment of certain aquatic bacteria that draw their energy supply from sunlight.
The marketing approval in Mexico follows the recent completion of a second Phase III clinical trial in Europe. This randomized pivot study compared disease progression, the cancer-free rate and urinary and erectile functions in patients including those undergoing active surveillance, with a follow-up of two years.
It involved more than 400 patients at 43 hospitals in 11 European countries and is under evaluation by the European Medicines Agency (EMA).
The therapy involves an intravenous infusion of TOOKAD Soluble, immediately followed by near-infrared laser illumination through thin optic fibers inserted into the cancerous tissue, while doctors control the process by ultrasound.
The non-toxic drug remains in the patient’s blood for three or four hours. Confined illumination of the diseased tissue activates the drug, resulting in the extensive generation of short-lived toxic molecules. The highly reactive oxygen and nitric oxide radicals initiate speedy occlusion and destruction of the tumor’s blood vessels, followed by necrotic death of the entire tumor while nearby healthy structures and their functions are spared.
The use of near-infrared illumination, the rapid clearance of the drug from the body and the unique non-thermal mechanism of action, make it possible to safely treat large, deeply embedded cancerous tissue using a minimally invasive procedure.

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The recent marketing approval was provided to both the drug and the designated Vascular Targeted Photodynamic Therapy (VTP).
Under the approved focal therapy setting, TOOKAD Soluble VTP is performed during the day and takes just an hour and a half. Patients are discharged a few hours later and can resume routine activities within a few days, without any of the side effects frequently associated with prostate removal by surgery or radiotherapy.
This new minimally invasive technology offers a good alternative to patients diagnosed with early-stage prostate cancer, Salomon and Scherz said. The number of these patients has dramatically increased in the last two decades due to widespread screening relying on levels of prostate specific antigen (PSA). This population faces the dilemma of undergoing the radical treatment of prostate removal with the high risk of illness and remaining under active follow up with increased risk of further cancer progression.
Weizmann and Steba Biotech are carrying out an extensive oncological research program in collaboration with several clinical groups at New York’s Memorial Sloan Kettering Cancer Center. Four clinical studies for more advanced prostate cancer and other oncological indications stemming from this research are scheduled to start this year.
Yeda Research and Development Company, Weizmann’s technology transfer arm, has licensed the drug to Steba Biotech, which manufactures Tookad Soluble.
Yeda CEO Amir Naiberg, said: “Our cooperation with Steba covers 20 years of fruitful collaboration. The commitment made by the shareholders of Steba and their personal relationship and effective collaboration with Weizmann Institute scientists and Yeda, have enabled this tremendous accomplishment.”