Prospetive Study of Thalidomide Maintenance Therapy in High-Risk Diffuse Large B-Cell Lymphoma.

e19551 Background: Patients with high-risk diffuse large B-Cell lymphoma (DLBCL) have a unfavourable clinical outcome even treated with R-CHOP. Thalidomide inhibits angiogenesis and exerts complex immunomodulatory activities.This study aimed to explore the efficacy and the tolerability of thalidomide maintenance treatment in patients with high-risk DLBCL. Methods: Patients diagnosised as DLBCL with IPI≥2, aged ≥18 year-old, who achieved completed remission after induction therapy ,with full liver , kidney and bone-marrow function, were eligible for this study. Patients were assigned to receive thalidomide (100 mg/day, increased by 100 mg every 3 days to a maximum of 300 mg/day and aspirin 100 mg/day ) maintenance treatment for two years or observation.Primary endpoint was progression free survival (PFS) .Secondary endpoints were overall survival (OS) and safety. Results: From January 2009 to June 2013, 90 patients were enrolled in this study.30 patients were assigned to thalidomide maintenance treatment and 60 to observation as control group. At a median follow-up of 36months, 3-year PFS was superior for treatment group compared with control group in patients with IPI more than 2 (61.0% vs 39.3%,p=0.049 ). 3-year OS was also significant better in treatment group than in control group in patients with IPI more than 2 (66.7% vs 43.3%,p=0.004). Patients with IPI equal to 2 received thalidomide maintenance showed no significant 3-year PFS benefit and 3-year OS benefit (81.5% vs 72.8% ,90% vs 75.4%,p=0.730 and p=0.327 respectively). There was no grade 3 to 4 adverse events and no treatment-related deaths in patients received thalidomide maintenance. Conclusions: Thalidomide as the maintenance treatment improved the PFS and OS with high-risk DLBCL.