Researchers based at the Weizmann Institute in Rehovot have played a central role in developing a new light-sensitive drug that can lead to the complete destruction of the blood vessels connected to the prostate tumor, and thus the destruction of the tumor.
Prostate cancer hits one man out of six, with a five-year survival rate of 99% - compared to 40% or less 20 years ago. Early detection is critical, but the new drug is designed to treat even tumors discovered after they have begun to develop.
Israel21c reports that the new drug, named Tookad, is based on chlorophyll, which has a high absorption of light. Used in previously-existing photodynamic therapy (PDT), Tookad is significantly more effective than other drugs used in the past, which are based on hemoglobin pigment.
Effective Against Large Tumors
Tookad absorbs near-infra-red light, which penetrates more deeply and efficiently than other wavelengths. Using Tookad, Israel21c reports, "a single illuminated optical fiber can reach and eradicate a tumor with a diameter of up to 4 centimeters, and even larger growths can be treated by using several fibers. What this means is that the Israeli-developed drug is effective against large, solid tumors which previously had evaded the reach of other PDT drugs."
Another benefit of Tookad is that it can be flushed out of the body within two hours, reducing the need for patients to avoid sunlight for lengthy periods following treatment.
Prof. Avigdor Scherz of the Weizmann Institute's Plant Sciences Department and Prof. Yoram Salomon of the Biological Regulation Department invented the new photo-sensitive drug.
"We have proof that this treatment causes the destruction of the part of the prostate which contains the cancer," said McGill University Hospital urologist Dr. Mostafa Elhilali, who took part in trials of the new drug. The trials found that 46% of patients showed no evidence of prostate cancer after treatment with Tookad.