Consolidation treatment with Yttrium-90 ibritumomab tiuxetan after new induction regimen in patients with intermediate- and high-risk follicular lymphoma according to the follicular lymphoma international prognostic index: a multicenter, prospective phase II trial of the Spanish Lymphoma Oncology Group.

Relapse is the main cause of therapeutic failure in follicular lymphoma (FL). We set out to evaluate the role of consolidation with Yttrium-90 ibritumomab tiuxetan in patients with intermediate- and high-risk FL after four cycles of CHOP-R (cyclophosphamide, doxorubicin, vincristine, prednisone, rituximab) and two cycles of CHOP. Thirty patients were included. The overall response rate after consolidation therapy was 93%. Of the 18 patients who presented with a partial response after induction treatment, 11 had a complete response after consolidation treatment. The complete clinical response rate was 76.6%. The most important grade 3-4 toxicity was hematological, with 46% thrombopenia and 56% neutropenia. With a median follow-up of 26 months, the means for progression-free survival and overall survival were not reached. Our data support consolidation with Yttrium-90 ibritumomab tiuxetan as an effective treatment, which provides long progression-free and overall survival, in first line after a response to induction treatment in patients with intermediate- and high-risk FL.