LEUKEMIA DRUG SHOWS MODEST BENEFIT FOR PROSTATE CANCER
Johns Hopkins Kimmel Cancer Center researchers have found that the leukemia drug imatinib (Gleevec), which is being tested in various cancers including colon, ovarian and pancreas, may not work alone against prostate cancer. Previous studies have already found that imatinib is ineffective for metastatic prostate cancer. This new study shows only modest benefits in suppressing PSA levels for some men with localized prostate cancer. But, the researchers say that combining imatinib with other chemotherapy drugs may be something to study.
"Even though Imatinib was tolerable and easy to administer, using this drug alone was not enough to lower the majority of patients' PSA levels," says Theodore DeWeese, M.D., professor and chair of the Department of Radiation Oncology and Molecular Radiation Sciences at Johns Hopkins.
DeWeese's study is one of the first to evaluate imatinib in men with non-metastatic prostate cancer. All 24 patients had rising PSA levels -- a sign of relapse -- despite surgery to remove the prostate or radiation therapy to destroy it. PSA levels in six patients (22 percent) remained stable while receiving imatinib for one year, and two patients (7 percent) experienced a decline in PSA that was not statistically significant. The remaining patients' PSA levels increased while taking the drug. Other researchers at Hopkins are conducting studies on using the chemotherapy drug docetaxel in men with non-metastatic disease. DeWeese believes that results of this study may help determine if adding imatinib to chemotherapy is worth pursuing for these patients. He says, "With the combination strategy, we may be able to kill cancer cells by two different pathways."
(Abstract #2141, Proceedings of the American Society for Therapeutic Radiation and Oncology, 2005)