A Phase II Trial of CHOP Chemotherapy Followed by Yttrium 90 (⁹⁰Y) Ibritumomab Tiuxetan (Zevalin) for Previously Untreated Elderly Diffuse Large B-Cell Lymphoma (DLBCL) Patients.

In the last 20 years, the major improvement over the use of CHOP has been the addition of anti-CD20 immunotherapy (Rituximab). This advancement was first demonstrated in a randomized trial in elderly patients with diffuse large B-cell lymphoma (DLBCL). Single-agent radioimmunotherapy activity, in particular Yttrium 90 (⁹⁰Y) Ibritumomab Tiuxetan (Zevalin), has been demonstrated in heavily pretreated DLBCL patients. Recently, the preliminary data of a phase II trial have showed that ⁹⁰Y Ibritumomab Tiuxetan have useful activity in the treatment of relapsed/refractory elderly DLBCL (Morschhauser et al, Blood 2004, 104: 41a), with no unexpected toxicities observed. The results of this study support a further evaluation of ⁹⁰Y Ibritumomab Tiuxetan in combination with chemotherapy earlier in the time course of elderly DLBCL. We conducted a prospective, single-arm, open-label, non-randomized, phase II to evaluate the efficacy and safety of ⁹⁰Y Ibritumomab Tiuxetan of a novel new approach combining induction chemotherapy with CHOP followed by consolidation with ⁹⁰Y Ibritumomab Tiuxetan for patients with previously untreated elderly DLBCL. Patient eligibility was represented by: patients older than 60 years with biopsy-proven, untreated, bidimensionally measurable stage II, stage III, or stage IV DLBCL expressing the CD20 antigen; performance status of 0 to 2, a pretreatment granulocyte cell count of 1500/μL or greater, and a platelet count of 100.000/μL or greater. All patients were notified of the investigational nature of this study and signed a written informed consent approved in accordance with institutional guidelines, including the Declaration of Helsinki. The study was approved by the institutional review board. Patients were treated with standard CHOP chemotherapy every 21 days for 6 cycles. Patients were restaged 4 to 8 weeks after completion of the sixth cycle of CHOP chemotherapy. Patients achieving at least a partial response after 6 cycles of CHOP chemotherapy were eligible for consolidation with ⁹⁰Y Ibritumomab Tiuxetan provided the granulocyte count was greater than 1500/μL, the platelet count exceeded 100.000/μL, and the bone marrow examination at the completion of CHOP chemotherapy demonstrated no more than 25% involvement with lymphoma. All patients were to receive a single dose of ⁹⁰Y Ibritumomab Tiuxetan 14.8 MBq/kg (0.4 mCi/kg) up to a maximum dose of 1184 MBq (32 mCi). A total of 20 patients have been enrolled and preliminary results of this trial will be presented.