Rituximab in Combination with CHOP in Patients with Follicular Lymphoma: Analysis of Treatment Outcome of 552 Patients Treated in a Randomized Trial of the German Low Grade Lymphoma Study Group (GLSG) after a Follow up of 58 Months

Abstract

Abstract We have previously reported that compared to CHOP alone the addition of Rituximab (R) to CHOP significantly increases the response rate (RR), the time to treatment failure (TTF) and also the overall survival (OS) in patients with newly diagnosed advanced follicular lymphoma. However, in the previous report, the median observation time was short with 18 months and no data were reported on the outcome of different risk groups according to the FLIPI (Hiddemann et al., Blood 2005). We now report on the treatment outcome of 552 patients with advanced stage follicular lymphoma randomized between R-CHOP versus CHOP alone after a median follow up of 58 months. Responding patients < 60 yrs. of age underwent a second randomization in first remission for Interferon alpha maintenance (IFN) versus myeloablative radio-chemotherapy with subsequent stem cell transplantation (ASCT), whereas all older pts received IFN maintenance. R-CHOP induced a significantly higher RR (97% vs. 91%, p=0.005). Furthermore immunochemotherapy resulted in significantly longer TTF (median not reached vs. 35 months, 5-years TTF 65% vs. 32%, p<0.0001), response duration (RD, 5-years RD 66% vs. 35%, p<0.0001), and OS (5-years OS R-CHOP 90% vs. CHOP 84%, p = 0.0493). To analyse the impact of R-chemotherapy in different risk groups we performed subgroup analyses for patients with low (LR), intermediate (IR) or high risk (HR) according to the FLIPI: R-CHOP prolonged significantly TTF in all risk groups compared to CHOP alone (5-years TTF: 84% vs. 46% for LR (p=0.0021); 73% vs. 37% for IR (p<0.0001); 49% vs. 23% for HR (p<0.0001). The superiority of R-CHOP vs. CHOP could be documented in the patient group not treated with ASCT: the RD was significantly prolonged by the immunochemotherapy (5-years probability 62% vs. 26%, respectively; p<0.0001). This could not be seen in the group of younger patients consolidated with ASCT (5-years probability 78% vs. 66%, p=0.43). However, the number of events was too low to draw any final conclusion. These data with a mature follow-up demonstrate that first–line R-CHOP significantly improves response rate and TTF in patients with FL compared to the respective chemotherapy alone. However, they also demonstrate that R-chemotherapy might be not sufficient for a long-lasting improvement. This indicates the necessity to perform clinical trials that test whether adding consolidation and/or maintenance after initial cytoreduction further improves treatment outcome.