Rituximab, methotrexate, procarbazine and lomustine (R-MPL) for the treatment of primary Central nervous system lymphoma

The optimal high-dose methotrexate (HDMTX)-based combination therapy for primary central nervous system lymphoma is unknown. We report our experience with rituximab, HDMTX, procarbazine and lomustine (R-MPL) given as first-line treatment in our center. Fifty-two patients between 2006 and 2019 were included. Eighteen patients proceeded to autologous transplant or two cycles of intermediate-dose cytarabine. The median age was 62 y (range 28-94) and the Eastern Cooperative Oncology Group performance status (ECOG-PS) was ≥2 in 62% (32/52). The overall/complete response rates were 79% (41/52) and 52% (27/52), respectively. The median progression-free/overall survival was 19 m/84m, respectively. Grade 3-4 adverse events included infections (17%) and kidney injury (13%). Ten patients (19%) discontinued therapy for toxicity. There were no treatment-related deaths. In summary, in a cohort enriched in frail patients, R-MPL achieved good responses and OS and was safe for all ages. The PFS was sub-optimal, possibly explained by a low proportion of consolidation. This regimen should be evaluated prospectively.