The role of upfront lenalidomide maintenance for primary central nervous system lymphoma patients responding to first‐line mtx treatment

Background: Consolidation therapy improves duration of response in primary central nerves system lymphoma (PCNSL). Lenalidomide maintenance has shown potential activity in elder adults with PCNSL. However, the efficacy of front-line lenalidomide maintenance in non-elder PCNSL has never been elevated. We aim to evaluate the effect of lenalidomide maintenance on duration of response in newly-diagnosed PCNSLs Method: This is a retrospective, single-center analysis. The patients with PCNSL who achieved complete remission or partial remission after high-dose methotrexate induction therapy were enrolled. Lenalidomide maintenance of 25 mg/d was administered orally for 21 days of every 28-day for 24 months in 35 patients, and no further treatment in the observe group. The efficacy and safety data were analysis. Results: 69 patients were enrolled at Peking Union Medical College Hospital from 2003 to 2021. The median age was 58.0 years, and 50.7% (n = 35) were male. Patients totaling to 57 (82.6%) achieved CR and 12 (18.4%) achieved PR status. Thirty-five patients received lenalidomide maintenance, the median duration of lenalidomide was 18 (2–36) months. It was well tolerated and barely affected the quality of life. After a median follow-up of 32.6 months, there were fewer relapsing and death events in the maintenance group. However, the median PFS was similar between groups (36.1 months vs. 30.6 months, HR 0.78, p = 0.446), and so did the median OS (HR 0.4263, p = 0.091). In the PR patients after induction, lenalidomide maintenance improved PFS and OS significantly. Encore Abstract—previously submitted to EHA 2023 The research was funded by: CAMS Innovation Fund for Medical Sciences (CIFMS) 2021-I2M-C&T-B-005. Keywords: aggressive B-cell non-Hodgkin lymphoma, immunotherapy No conflicts of interests pertinent to the abstract.