Radioimmunotherapy with Zevalin in Patients with Non-Hodgkin's Lymphoma

The aim of this prospective study was to asses the value of new radioimmunotherapy treatment with Zevalin (IgGl monoclonal antibody covalently bound to tiuxetan and labeled with Y-90) for adult patients with refractory or relapsed CD20+ follicular B-cell non- Hodgkin's lymphoma (NHL). This multicentric study included eight patients (median age 55 years, range 51 -59 years) from five hospitals in Croatia. The treatment involved a day 1 infusion of rituximab 250 mg /m2 ; a second infusion of rituximab on day 8, followed by "slow push" 10 minute infusion of Zevalin (median dose 1020 MBq ; range 820-1177 MBq). On follow-up 12 weeks after treatment response was achieved in six patients (75%). In three patients tumor mass was completely disappeared (complete response), and in other three patients tumor mass was significantly decreased (partial response). Hematological toxicity was observed in three patients and manifested with infections requiring hospitalization. One patient died because of extreme pancytopenia and Candida sepsis, in spite of support with granulocyte colony-stimulating factor. The median time to lowest blood counts was four weeks after Zevalin injection. Acute and non-hematological side-effects were not observed. Our preliminary results confirmed Zevalin as a very effective therapy for patients with refractory or relapsed CD20+ follicular B-cell NHL. One should be aware of hematologic toxicity ; therefore the close follow-up is required.