90‐yttrium‐ibritumomab tiuxetan consolidation of fludarabine, mitoxantrone, rituximab in intermediate/high‐risk follicular lymphoma: updated long‐term results after a median follow‐up of 7 years

Abstract

Radioimmunotherapy ( RIT) after an induction phase with conventional chemoimmunotherapy became an attractive strategy of consolidation for patients with advanced follicular lymphoma: in particular, in many studies RIT was represented by yttrium‐90‐ibritumomab tiuxetan ( ⁹⁰Y‐ IT). Independently by the different front‐line treatment, updates on the long‐term follow‐up of these studies are needed because the disease course of follicular lymphoma is characterised by multiple relapses and progressively shorter durations of response. We report updated long‐term efficacy and toxicity results of a multicenter phase II study on sequential treatment with four cycles of fludarabine, mitoxantrone, and rituximab followed by ⁹⁰Y‐ IT as front‐line therapy for untreated patients with intermediate/high‐risk follicular lymphoma. With a median follow‐up of 84 months, only 19/49 (38.8%) complete response patients relapsed, yielding an estimated long‐term disease‐free survival of 62.6%. The 7‐year overall survival was 72.7%. Four (7.3%) second acute myeloid leukemia occurred, with a median time following RIT of 42 months. A relevant patients' responsiveness to subsequent therapies occurred: approximately 65% of relapsed patients obtained a good clinical response after the second‐line treatment. These data represented the first evidence of a real role even in the long period of 90Y‐ IT after a fludarabine‐containing regimen plus rituximab in the treatment of high‐risk follicular lymphoma.