Long-Term Remission (>3 years) after Rituximab Monotherapy Used for Patients with Relapsed Indolent Non-Hodgkin Lymphomas (NHL)

Background: Rituximab has demonstrated significant clinical efficacy in the treatment of NHL, particularly in combination with chemotherapy, and its use has dramatically changed the treatment and outcome of both indolent and aggressive B-cell NHL over the past decade. Furthermore, consistent toxicity data have been obtained with a safe and tolerable profile in a large majority of patients. Aim: The objective of this retrospective study is to evaluate the long-term efficacy of rituximab monotherapy (4 weekly infusion at induction followed by 4 infusion every 2 months as consolidation) used for patients with relapsed indolent NHL. Results: From May 1998 through January 2011, Among 919 patients with indolent NHL treated in our department, 488 (53%) relapsed and were treated with rituximab alone (first and later relapse). 126 (26%) responded and were still in response 2 years later. These 126 patients (68 (54%) males and 58 (46%) females with a median age of 61 y; range: 17-94) are the subject of our analysis. 24% were over 70 years old, 45% were in first relapsed and 25% in later relapsed. Only 16% of the population have more than one co-morbidities (cardiac and or renal respectively); 79% a normal PS (0-1) with only 4 patients having a PS >2; 80% no bulky disease but 72% a disseminated disease (73% stage III and IV). In this study, 60 (48%) patients had a follicular lymphoma with 50% at an intermediate risk group according to the FLIPI score ; 20 (16%) a marginal zone lymphoma, and 43 (34%) a small lymphocytic or lymphoplasmacytic lymphoma and 3 patients other characteristics of lymphoproliferative disorders. After rituximab monotherapy, 55% of the entire cohort was in complete response (CR) and 31% in CRu or partial response and 5% in stable disease. Among these 126 patients, 74% progressed later than 3 years (38% later than 5 years). With a median follow-up of 6.5 years, 4-year and 8-year PFS were 70% and 30%, respectively. 18% had transformation into Richter syndrome and 12 patients have died. Conclusion: Rituximab monotherapy is an effective therapy in selected relapsed indolent NHL and allows long-term response. This strategy could be used as “spare of chemotherapy” which is an important question today, especially in indolent not curable disease. Disclosures No relevant conflicts of interest to declare.