According to a University of Pittsburgh Medical Center (UPMC) study, patients with advanced non-Hodgkin's lymphoma (NHL) previously treated with chemotherapy and adult stem cell transplantation can safely tolerate Zevalin (ibritumomab tiuxetan), a radiolabeled monoclonal antibody that targets radiation directly to a tumor.
The study, presented at the 41st annual meeting of the American Society of Clinical Oncology (ASCO) in Orlando, indicates that NHL patients who have received prior therapies for their disease respond safely to treatment with Zevalin.
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.