A monoclonal antibody linked to the radioisotope, yttrium-90, Zevalin targets the CD20 antigen on the surface of mature B cells and B-cell tumors, and was approved in 2002 for the treatment of relapsed or refractory B-cell NHL. With Zevalin, radiation is added to the antibody to target the cancerous cells to the effects of ionizing irradiation. A major potential benefit to Zevalin is that treatment takes approximately eight days compared to six months of standard therapy.
"Patients with non-Hodgkin's lymphoma who have failed standard chemotherapy and have received stem cell transplantation have few treatment options available," said Samuel Jacobs, M.D., lead investigator and associate director for clinical investigations at the University of Pittsburgh Cancer Institute and UPMC Cancer Centers. "As a result, it is crucial to evaluate novel therapies in the advanced disease setting. Our preliminary results indicate that Zevalin is a safe option for these patients."
In the study, 11 patients who had received at least three prior therapy regimens including high-dose chemotherapy with adult stem cell transplantation were treated with Zevalin. Responses to the treatment were assessed pre- and post-treatment with PET/CT scans. According to results, three patients responded – two with partial responses and one with a complete response lasting 11 months. Another patient remains disease-free at 14 months follow-up. Side effects from treatment were expected and included thrombocytopenia – the reduction of platelets in the blood making it more difficult to clot, and neutropenia – a white blood cell reduction that places patients at greater risk for infections. Only two patients developed a serious infection.
"These preliminary results are promising and indicate that Zevalin is feasible and safe in NHL patients with a history of adult stem cell transplantation," said Dr. Jacobs. "Further research will help us fully assess patients' clinical responses to the treatment."
Non-Hodgkin's lymphoma is a group of several closely related cancers that affect the body's lymphatic system. Once a rare disease, NHL is now the fifth most common cancer in the United States. NHLs are classified based on the specific type of lymphoma cells involved in the disease and how fast the tumors are growing (grade). Low-grade lymphoma describes tumors that grow slowly, yet are rarely cured and often widespread at the time of diagnosis. The type and grade of the disease are important in helping physicians determine appropriate treatment for patients.
Co-investigators of the study include J. Joyce, M.D., UPMC; M.W. Schuster, M.D., Weill Medical College of Cornell University; B. McCook, M.D., University of Pittsburgh School of Medicine; F. Torok, M.D., UPMC; N. Avril, M.D., University of Pittsburgh School of Medicine; and N. Vidnovic, UPMC.
The study is published in abstract number 6669 in the 2005 ASCO Annual Meeting Proceedings.