Y-90-Ibritumomab Tiuxetan Consolidation After Autologous Stem Cell Transplantation Improves Survival of Patients with Intermediate-/High-risk Diffuse Large B-cell Lymphoma Not Responding Adequately to First-line Treatment

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma entity whose prognosis for high-risk patients is poor. Aggressive salvage treatments to improve patient outcome have been unsatisfactory. Therefore, we evaluated the efficacy of yttrium-90-ibritumomab tiuxetan (Zevalin®; (90)Y-IT) consolidation after early salvage chemotherapy with autologous stem cell transplantation. Thirty-seven patients with intermediate-high risk DLBCL not in complete remission (CR) after three cycles of rituximab, cyclophosphomide, doxorubicin, vincristine and prednisone (R-CHOP) were assessed retrospectively. After early salvage treatment, 70% achieved CR and 30% partial remission. Twenty patients underwent additional consolidation with (90)Y-IT. During the 3-year follow-up, 50% in the (90)Y-IT-treated group experienced relapse compared to 82.3% in the other cohort (p=0.002). Progression- and disease-free survival were significantly longer in the (90)Y-IT group. However, probably due to the relatively short follow-up period, no difference in overall survival was observed. (90)Y-IT consolidation after early salvage chemotherapy improves treatment responses and reduces the percentage of relapses without significant additional toxicities.