High Response Rate and Low Toxicity of Rituximab, Vinorelbine, Ifosfamide, Mitoxantrone and Prednisone Combination for the Treatment of Diffuse Large B Cell Lymphoma In First Relapse: Early Results of the R-NIMP GOELAMS Study.

Abstract 2796 Background: Diffuse large B-cell lymphoma (DLBCL) relapse prognosis is poor, and the optimal salvage treatment is not known. In a previous pilot study, vinorelbine, ifosfamide, mitoxantrone, and prednisone (NIMP) without rituximab has shown a promising efficacy in the setting of relapsed DLBCL. Aims: To evaluate the efficacy and tolerability of the combination of rituximab and NIMP in the treatment of DLBCL in first relapse. Methods: This multicentric, single-arm phase II study included patients 18 to 75 years old, with CD20-positive DLBCL in first relapse (defined as having obtained at least a PR of more than 50% to an anthracycline-based front-line regimen) occurring more than 30 days after the last chemotherapy cycle or more than one year after an autologous stem cell transplantation (ASCT) in first line. Other inclusion criteria were a performance status ≤ 2, absence of CNS involvement, and having signed an informed consent form. Patients with evidence of transformation from indolent lymphoma, primary refractory disease, or positive HIV tests were excluded. Initial and relapse biopsies were centrally reviewed. Patients received intravenous (IV) rituximab 375 mg/m2 D1, ifosfamide 1000 mg/m2 as a continuous infusion from D1 to D5, IV vinorelbine 25 mg/m2 D1 and D15, IV mitoxantrone 10 mg/m2 D1, and oral prednisone 1 mg/kg D1 to D5, repeated every 28 days for three cycles. Pegfilgrastim support (6 mg at D7) was recommended. The primary endpoint was CR/CRu after 3 cycles, and was assessed by computed tomography according to the IWG criteria. Mobilization, consolidation or subsequent salvage therapy was decided at the discretion of the investigator. All the monitoring and data management were performed by the GOELAMS clinical research assistants, with a database lock on July 27, 2010. Results: Fifty patients (21[42%] women and 29[58%] men) were included in 18 centers between December 2004 and accrual closure in April 2010. All patients received at least 1 cycle of R-NIMP. Forty-five patients were available for central pathology review, toxicity and response. The central review of all patient samples confirmed DLBCL histology. Median age at study entry was 62.9 years (range: 34.8–75.6). Median time between first diagnosis of DLBCL and relapse was 18.0 months (range: 2.4–208). The following tumor responses were observed: 67.9 % overall response rate with 20 CR/CRu (43.5%), 11 PR (24.4%), 2 SD (4.4%), and 12 (26.7%) progressed under therapy. Toxicity information was available for 109/120 (91 %) of the first 3 cycles of R-NIMP administered. The following toxicities were observed (all grades, ≥ grade 3 for all cycles): anemia (87%, 8%), neutropenia (66%; 46%), thrombopenia (65%, 14%), elevated liver tests (39%, 0%), constipation (25%, 0%), kidney failure (7%, 0%), nausea (14%, 0%), vomiting (6%, 0%), allergic reactions (5%, 0%), and mucositis (5%, 0%). Twenty-nine infectious events (27%) were observed needing hospitalization in 9 cases. Twenty-nine patients received consolidation therapy at the discretion of the investigator. Of the 11 patients who received 3 additional cycles of R-NIMP, 3 remained in CR/CRu, 1 remained in PR, 4 converted from PR to CR/CRu, and 3 progressed. Among the 11 patients who underwent ASCT, 9 were in CR at the end of the procedure, one patient died of toxicity and 1 progressed. For the 12 patients mobilized after a R-NIMP cycle, a median of 1 apheresis (range 1–4) was necessary to harvest a median of 3.85 × 106 CD34+ cells/kg. The median time to second progression or relapse (TTP2) was 11.4 months, and the median survival of 55.5 months. On multivariate analysis, the variable associated with a longer TTP2 was the achievement of CR/Cru (RR: 0,12; CI95%: 0.03–0,39; p=0.0006). Within the subgroup of patients having received a consolidation treatment, having received an ASCT was associated with a longer TTP2 (RR: 0.20; CI95%: 0.04–0.98; p=0.047). Time to first relapse or previous rituximab exposure did not affect TTP2 nor OS, whereas relapse-IPI (as a continuous variable, by 1 additional risk factor) was associated with a poor survival (RR: 2.59; CI95%: 1.25–4.45; p=0.008). Conclusions: R-NIMP is a well-tolerated regimen, yields a high complete response rate, and allows for successful mobilization of CD34+ cells. This regimen is a suitable salvage treatment for relapsed DLBCL prior to appropriate consolidation. Further investigation is warranted. ClinicalTrials.gov number: NCT00842595 Disclosures: Off Label Use: Vinorelbine in Non-Hodgkin's Lymphoma (Off-label in France).