Outcomes of R-MPV followed by ara-c in primary central nervous system lymphoma: A single-center retrospective analysis.

e19046 Background: Primary central nervous system lymphoma (PCNSL) lymphoma is a rare non-Hodgkin’s Lymphoma. Currently, there is no uniform consensus in the optimal management of PCNSL. In patients that can tolerate systemic therapy, induction therapy is typically done with a high-dose methotrexate-based regimen, due to evidence of better penetration of the blood brain barrier. One such regimens is high dose methotrexate combined with rituximab, procarbazine, and vincristine (R-MPV). Options for consolidation therapy include high-dose systemic therapy with stem cell rescue (ASCT), whole brain radio therapy (WBRT) and high-dose cytarabine (ara-c) with or without etoposide (EA). At our institution we utilize an R-MPV induction approach with some form of ara-c consolidation without etoposide. We aimed to execute a retrospective cohort study to analyze outcomes of this approach. Methods: All the patients diagnosed with PCNSL who received an induction regimen of R-MPV from 10/01/2020 to 06/01/2023 were included. Data was then gathered by chart review of the electronic medical record. Treatment outcomes were evaluated based on imaging with brain MRIs and PET scans. Central findings such as complete response (CR) rate, progression free survival (PFS) and overall survival (OS) were ascertained. Results: 10 charts were reviewed. 9 out of the 10 patients had a histological presentation consistent with diffuse large B-cell lymphoma; 1 patient had a diagnosis of B-cell lymphoma. In terms of demographics, the patients ages ranged from 54 to 83 years, with a median of 74 years. Complete response was achieved in 5 out of the 10 patients (CR rate of 50%), and no relapse was noted in any of these patients. 2 out of the 10 patients progressed on treatment, with 1 dying from progression of the disease. The median follow-up for patients who were still alive was 24 months. 2-year PFS was 80%, and 2-year OS was 90%. Median PFS and OS were not reached. Mean PFS and OS were 28 months and 30.5 months respectively. Conclusions: Based on our study results, the CR rate we observed for R-MPV appears consistent with existing literature on this regimen and other methotrexate-based induction regimens. Our results for R-MPV with ara-c consolidation provides similar outcomes to existing studies on treatment with different methotrexate-based induction and consolidation with ASCT, particularly the 80% PFS we observed. This percent PFS also appears similar to studies of consolidation with ara-c and EA, and superior to PFS with WBRT. Overall, these results are reassuring as in a specific set of older patients who might not be candidates for ASCT, our specific nonmyeloablative approach could be worthwhile. However, our study does have the limitation of being a single center retrospective perspective. Table: see text