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, nonrandomizedphase II combination chemotherapy with cyclophosphamide, doxorubicin,vincristine, and prednisone (CHOP) plus radioimmunotherapy trialwas conducted to evaluate the efficacy and safety in untreatedelderly diffuse large B-cell lymphoma (DLBCL) patients. Patients and methods: From February 2005 to April 2006, in ourinstitute we treated 20 eligible elderly (age 60 years) patientswith previously untreated DLBCL using a novel regimen consistingof six cycles of CHOP chemotherapy followed 6–10 weekslater by ⁹⁰Y ibritumomab tiuxetan. Results: The overall response rate to the entire treatment regimenwas 100%, including 95% complete remission (CR) and 5% partialremission. Four (80%) of the five patients who achieved lessthan a CR with CHOP improved their remission status after radioimmunotherapy.With a median follow-up of 15 months, the 2-year progression-freesurvival was estimated to be 75%, with a 2-year overall survivalof 95%. The ⁹⁰Y ibritumomab tiuxetan toxicity included grade3 hematologic toxicity in 12 of 20 patients; the most commongrade 3 toxic effects were neutropenia (12 patients) and thrombocytopenia(7 patients). Transfusions of red blood cells and/or plateletswere given to one patient. Conclusion: This study has established the feasibility, tolerability,and efficacy of this regimen for elderly patients with DLBCL. Key words: Chemotherapy, DLBCL, elderly patients, yttrium 90 ibritumomab tiuxetanReceived for publication April 30, 2007. Revision received July 25, 2007. Revision received September 13, 2007. Accepted for publication November 12, 2007.