A phase II trial of CHOP chemotherapy followed by yttrium 90 ibritumomab tiuxetan (Zevalin) for previously untreated elderly diffuse large B-cell lymphoma patients

Background: A prospective, single-arm, open-label, nonrandomized phase II combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus radioimmunotherapy trial was conducted to evaluate the efficacy and safety in untreated elderly diffuse large B-cell lymphoma (DLBCL) patients. Patients and methods: From February 2005 to April 2006, in our institute we treated 20 eligible elderly (age ≥60 years) patients with previously untreated DLBCL using a novel regimen consisting of six cycles of CHOP chemotherapy followed 6-10 weeks later by ⁹⁰Y ibritumomab tiuxetan. Results: The overall response rate to the entire treatment regimen was 100%, including 95% complete remission (CR) and 5% partial remission. Four (80%) of the five patients who achieved less than a CR with CHOP improved their remission status after radioimmunotherapy. With a median follow-up of 15 months, the 2-year progression-free survival was estimated to be 75%, with a 2-year overall survival of 95%. The ⁹⁰Y ibritumomab tiuxetan toxicity included grade ≥3 hematologic toxicity in 12 of 20 patients; the most common grade ≥3 toxic effects were neutropenia (12 patients) and thrombocytopenia (7 patients). Transfusions of red blood cells and/or platelets were given to one patient. Conclusion: This study has established the feasibility, tolerability, and efficacy of this regimen for elderly patients with DLBCL.