Short duration immunochemotherapy followed by radioimmunotherapy consolidation is effective and well tolerated in relapsed follicular lymphoma: 5-year results from a UK National Cancer Research Institute Lymphoma Group study

We report a phase II study to evaluate the efficacy and toxicity of abbreviated immunochemotherapy followed by (90) Y Ibritumomab tiuxetan ((90) Y-IT) in patients with recurrent follicular lymphoma. Of the 52 patients enrolled, 50 were treated with three cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) or R-CVP (rituximab, cyclophosphamide, vincristine, prednisolone), followed by (90) Y-IT regimen (15 MBq/kg, maximum 1200 MBq) preceded by two infusions of 250 mg/m(2) rituximab. The overall response rate was 98% with complete response (CR) 30% and partial response (PR) 68%. 18 patients with a PR following chemotherapy improved to a CR following (90) Y-IT: a conversion rate of 40%. Seven patients with PR following (90) Y-IT subsequently improved to a CR 12-18 months later, leading to an overall CR rate of 44%. With a median follow-up of 5 years, median progression-free survival was 23·1 months and overall survival was 77·5% at 5 years. High trough serum rituximab levels (median 112 μg/ml; range 52-241) were attained after four doses of rituximab, prior to (90) Y-IT; this was not found to influence response rates. The treatment was well tolerated with few (13·5%) grade 3 or 4 infective episodes and manageable haematological toxicity. Abbreviated immunochemotherapy followed by (90) Y-IT is an effective and well-tolerated treatment in recurrent follicular lymphoma patients previously exposed to rituximab.

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clinicaltrials.gov identifier: NCT00637832.

Zevalin and BEAM (Z-BEAM) versus rituximab and BEAM (R-BEAM) conditioning chemotherapy prior to autologous stem cell transplantation in patients with mantle cell lymphoma

Early relapse is common in patients with mantle cell lymphoma (MCL) highlighting the unmet need for further improvement of therapeutic options for these patients. CD20 inhibition combined with induction chemotherapy as well as consolidation with high-dose chemotherapy (HDCT) is increasingly considered cornerstones within current therapy algorithms of MCL whereas the role of radioimmunotherapy is unclear. This retrospective single center study compared 46 consecutive MCL patients receiving HDCT in first or second remission. Thirty-five patients had rituximab and BEAM (R-BEAM), and 11 patients received ibritumomab tiuxetan (Zevalin®), an Yttrium-90 labeled CD20 targeting antibody, prior to BEAM (Z-BEAM) followed by autologous stem cell transplantation (ASCT). We observed that the 5-year overall survival (OS) in the R-BEAM and Z-BEAM groups was 55% and 71% (p = 0.288), and the 4-year progression free survival (PFS) was 32% and 41%, respectively (p = 0.300). There were no treatment related deaths in both groups, and we observed no differences in toxicities, infection rates or engraftment. Our data suggest that the Z-BEAM conditioning regimen followed by ASCT is well tolerated, but was not associated with significantly improved survival compared to R-BEAM. Copyright © 2015 John Wiley & Sons, Ltd.

90Y-ibritumomab tiuxetan radiotherapy as first-line therapy for early stage low-grade B-cell lymphomas, including bulky disease

(90) Y-ibritumomab-tiuxetan ((90) YIT) was used as a first-line therapy for patients with early-stage follicular lymphoma (FL) or marginal zone B-cell lymphoma (MZL). Thirty-one patients were treated, with an overall 3-month response rate of 100% (68% complete response, 29% unconfirmed complete response and 3% partial response). At a median follow-up of 56 months, ten patients (32%) had disease relapse or progression. The progression-free rates at 3 and 5 years were lower in males, patients with FL, stage II disease and non-bulky disease, although they did not reach statistical significance. Grade 3-4 neutropenia, thrombocytopenia and anaemia were 61%, 35%, and 3%, respectively. (90) YIT was well tolerated, including in those patients over 60 years old, and achieved high response rates in patients with early-stage low-grade B-cell lymphomas. Bulky disease did not adversely affect tumour response.

Yttrium ibritumomab tiuxetan in the treatment of non-Hodgkin's lymphoma: current status and future prospects

After nearly three decades with little change in the treatment for B-cell non-Hodgkin's lymphoma, the addition of immunotherapy has had a profound effect on the treatment of this group of diseases. A more subtle addition to the armentarium has been the radiolabeled monoclonal antibodies, (90)yttrium ibritumomab tiuxetan and (131)iodine tositumomab. Unfortunately these drugs have been underutilized. This is, in part, because of the need for coordination between specialties, concern about long-term effects, possible limitations on the tolerance of subsequent therapies and, in part, because of reimbursement factors. In this review, the studies in relapsed and refractory disease are discussed and the very promising results reported from phase II studies using radioimmunotherapy as first-line. Potential mechanisms of resistance to monoclonal antibodies are postulated based on alterations in cell signaling pathways that have been observed in lymphoma cell lines resistant to rituximab. It is anticipated that as mechanisms of resistance are better understood for both unlabeled and labeled monoclonal antibodies, biomarkers will not only predict their efficacy but also lead to the development of therapies to overcome resistance.