Combining Ionizing Radiation and Radio-Immunotherapy Appears Safe for Lymphoma Patients

Combining external beam radiotherapy and the immunotherapy drug Zevalin appears to be a safe and effective treatment for patients with some of the most common types of non-Hodgkin's lymphoma, according to a new study presented October 9, 2002, at the American Society for Therapeutic Radiology and Oncology's Annual Meeting in New Orleans.

Zevalin (Ibritumomab Tiuxetan incorporating the beta emitter Y-90) recently became the first radiolabeled antibody compound to receive FDA approval for clinical use against relapsed and refractory low grade CD20+ B cell lymphoma. In order to establish baseline data on clinical safety and effectiveness of combining ionizing radiation and radio-immunotherapy, researchers analyzed database information on patients registered in Zevalin clinical trials who had previously received external beam radiotherapy.

Data for 211 patients enrolled in Zevalin clinical trials were divided into two groups: a group of 60 patients who had received prior external beam radiotherapy, and a group of 151 patients who had not. Researchers discovered that prior radiation therapy was not a significant predictor of either likelihood of radio-immunotherapy response or likelihood of subsequent development of most types of organ-specific toxicity.

"The combination of external beam radiotherapy and Zevalin appears to be feasible and safe for this patient group," said Roger M. Macklis, M.D., Chair of the Department of Radiation Oncology at the Cleveland Clinic Foundation and lead author of the study. "Future research will examine whether this type of treatment adds to the effectiveness of antibody-based therapy and extends the potential of radio-immunotherapy to additional patient groups."