⁹⁰Y-Ibritumomab Treatment for Relapsed and/or Refractory B Cell Type Non-Hodgkin’s Lymphoma. Multiinstitutional Argentinian Study.

The radionucleid conjugate with monoclonal antibodies (antiCD20/⁹⁰Y-ibritumomab tiuxetan) have been approved for the treatment of relapsed, refractory and transformed (high grade) follicular lymphomas. Between September 2005 and August 2007, 41 patients with refractory/relapsed lymphoma were enrolled. Median age was 62 yrs old (45–83). Twenty were women and 21 were men. Thirty three were follicular and 5 were mantle cell lymphoma and 3 transformed lymphoma. Eighteen patients had bulky disease, 8 had bone marrow involvement and 21 had stage III-IV disease. Median time from diagnosis was 5 years (0.5–29). Twenty one had received 1–2 previous treatments, and 20 pts had received 3–5 previous treatments including 5 pts with autologous bone marrow transplantation. All had previously received anti-CD20 monoclonal antibody therapy. Six pts received previous radiotherapy. ⁹⁰Y-Ibritumomab (Zevamab™ Bayer-Schering Argentina) was administered at 0.3 or 0.4 mCi, based on initial platelet count. Seven days before, and on the same day of the immunoconjugate administration, pts received rituximab 250 mg/m2. Thirty eight were evaluable for response. Thirty four (89%) pts responded: 20 CR (53%) and 14 PR (36%). With a median follow-up of 10 months, 60% of pts were expected to continue in CR at 18 months. Overall survival at the same period for the entire group was 89%. Nineteen pts (46%) required filgrastim administration for neutropenia, Ten pts (24%) required platelet transfusions, 10 pts had neutropenia plus fever and they had to be admitted for complicated pancytopenia, 8 pts required red blood cells transfusion. Two patient died 30 and 40 days after treatment with hypoplastic bone marrow complicated with septicemia and in the post autologous bone marrow transplantation period, respectively. Four pts with previous bone marrow transplantation, required filgrastim, transfusions and 2/3 had febrile neutropenia. Our experience with ⁹⁰Y-ibritumomab in relapsed and refractory folicullar lymphoma shows 53% CR. Even heavily treated pts, that had previous bone marrow transplantation were able to receive the radioimmunoconjugate, although they required extra support. Our experience favours the use of ⁹⁰Y-Ibritumomab tiuxetan in relapsed and refractory lymphomas even if they had received previous autologous bone marrow transplantation.