Iodide-131 humanized monoclonal antibody to CD 25 in relapsed Hodgkin's lymphoma - First results in compassionate use

1150 Objectives To assess response to treatment with Iodine-131 Basiliximab (a monoclonal antibody to CD 25) in patients with CD25 positive relapsed Hodgkin’s Disease treated in a compassionate use programme. Methods Patients received 1200MBq/m2 (1800-2640 MBq) I-131 Basiliximab. Treatment response was assessed using F-18 FDG PET-CT scan. Scans were performed at pre-treatment and 4, 8 and 12 weeks after treatment. A significant response was defined as a 50% reduction in the total of metabolically active tumor sites assessed visually. Progressive disease was defined as any increase in metabolically active tumor. Toxicity was recorded. Toxicity and previous treatment was also recorded. Results Nine patients, 4 male, (median age 37, range 26-69). All had stage III or IV disease prior to therapy and all had up to 6 previous chemotherapy treatments. Five had previous radiotherapy and 6 had bone marrow transplant. Single cycle of RIT was given to 8 patients and 2 cycles to a one patient. A significant reduction in active tumor is noted in 8 patients at 4 weeks, sustained in 4 patients at 8 weeks. Of the 4 patients evaluable at 12 weeks, 2 had a sustained response. A single patient progressed at 4 weeks. There were no treatment-related deaths. Toxicity was mainly limited to neutropenia and thrombocytopenia (grades 1 or 2) and Thrombocytopenia (grade 2 or 3) with no marked reduction in performance status noted. Conclusions These results demonstrate that Iodine-131 Basiliximab has potential in the treatment of heavily pre-treated patients with refractory CD 25 relapsed Hodgkin’s disease