Abstract
OBJECTIVE: To evaluate the efficacy of rituximab (R) when added to high-dose methotrexate (HD-MTX) in patients with newly diagnosed immunocompetent primary CNS lymphomas (PCNSLs). METHODS: Immunocompetent adults with newly diagnosed PCNSL treated at The Johns Hopkins Hospital between 1995 and 2012 were investigated. From 1995 to 2008, patients received HD-MTX monotherapy (8 g/m2 initially every 2 weeks and after complete response [CR] monthly to complete 12 months of therapy). From 2008 to 2012, patients received the same HD-MTX with rituximab (375 mg/m2) with each HD-MTX treatment. CR rates and median overall and progression-free survival were analyzed for each patient cohort in this single-institution, retrospective study. RESULTS: A total of 81 patients were identified: 54 received HD-MTX (median age 66 years) while 27 received HD-MTX/R (median age 65 years). CR rates were 36% in the HD-MTX cohort and 73% in the HD-MTX/R cohort (p = 0.0145). Median progression-free survival was 4.5 months in the HD-MTX cohort and 26.7 months in the HD-MTX/R cohort (p = 0.003). Median overall survival was 16.3 months in the HD-MTX cohort and has not yet been reached in the HD-MTX/R cohort (p = 0.01). CONCLUSIONS: The addition of rituximab to HD-MTX appears to improve CR rates as well as overall and progression-free survival in patients with newly diagnosed PCNSL. Comparisons of long-term survival in the 2 cohorts await further maturation of the data. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that in immunocompetent patients with PCNSL, HD-MTX plus rituximab compared with HD-MTX alone improves CR and overall survival rates.