Efficacy of 90yttrium-Ibritumomab Tiuxetan in Extranodal Marginal-Zone Lymphoma,

Abstract

Abstract 3713 BACKGROUND:To evaluate clinical activity of 90Y-Ibritumomab Tiuxetan in Extranodal Marginal-Zone Lymphoma.PATIENTS AND METHODS: From May 2004 to April 2011 thirty patients affected by relapsed/refractory Marginal-Zone Lymphoma - arisen at any extranodal site - were enrolled to receive 90Y-Ibritumomab Tiuxetan at the activity of 0,4 mCi/kg. Median age was 57 years (range 36–83 ys); 16 female and 14 male. Thirtheen patients had Helicobacter Pylori-negative gastric Mucosa-Associated Lymphoid tissue Non Hodgkin Lymphoma, while 17 patients had extra-gastric Marginal-Zone Lymphoma. At time of treatment 13 out of 30 patients had disseminated disease (stage III/IV; Ann-Arbor Staging System); 4 patients bone marrow involvement. All patients had received a previous treatment with a maximum of 7. The median number of previous treatments administered - including antibiotics, CT, RT or surgery - was 1 with a maximum of 7; 14/30 had received at least 2 previous treatments, 5 of them more than 3. RESULTS:Toxicities were primarily hematological, as expected, and reversible; infection or febrile neutropenia was observed in 3 patients. Up to now no myelodisplastic syndrome occurred. Overall Response Rate was 90%: twenty-three patients achieved a complete response (77%); partial response occurred in 4 patients (13%), stable disease in 2 patients (7%) and 1 progression (3%). With a median follow-up of 47 months, 2 patients relapsed after complete response; 8 out of 20 complete responses are still responder after > 3 years and 5 patients after > 5 years.TABLE 1:Overall Survival and Duration of Response (Kaplan-Meier estimates)N. ptsEvents (%)Median (months)Overall Survival301 (3.3)Not reachedDuration of Response296 (20.7)81.3Response Rate = 90%, 95% CI: (73.5,97.9) CONCLUSIONS:90Y-Ibritumomab Tiuxetan seems to be active in patients with Extranodal Marginal-Zone Lymphoma resistant or refractory to conventional systemic treatment. These results suggest as a single shot of radioimmunotherapy could represent a possible option for the treatment of relapsed Marginal Zone Lymphoma. Disclosures:No relevant conflicts of interest to declare.