Assessing the role of cytarabine-based regimens in mantle cell lymphoma: A real world study.

7058 Background: Mantle cell lymphoma (MCL) is an aggressive subtype of non-Hodgkin lymphoma. For decades, cytarabine-based regimens have been the cornerstone of MCL treatment, offering substantial efficacy but often at the cost of significant toxicity. More recently, non-cytarabine-based regimens, such as bendamustine combined with rituximab, have emerged as a promising alternative, demonstrating comparable efficacy with more favorable toxicity profile. This study aims to compare the clinical efficacy of cytarabine-based (Ara-C) versus non-cytarabine-based (non-Ara-C) regimens. Methods: We conducted a retrospective cohort study for patients diagnosed with MCL between 2010 and 2023 at Allegheny Health Network and Markey Cancer Center. Data pertaining to demographics, MIPIc, Lugano stage and treatments at induction were collected. Patients were divided into two groups based on whether they received cytarabine based regimen during induction (Ara-c) or not (non-Ara-c). Primary outcomes were overall survival (OS) measured from the time of diagnosis to the time of last follow up or death, and relapse free survival (RFS), calculated from the time of diagnosis to the time of relapse, persistent or progressive disease at the last day of follow up. Sensitivity analysis, with censoring on the time of autologous bone marrow transplant (ASCT) was done. RFS and OS were compared between the two groups after weighted propensity score matching (PSM). Results: We identified 223 patients diagnosed with MCL. The median age was 67.7 (IQ 60-74.5), Majority of patients were males (71%). The median MIPIc score was 8.1(IQR 7-9.5). 72 patients (31%) were in the Ara-c group while 151 patients (69%) were in the non-Ara-c group. The median follow-up of 5.6 years (0.95CI 4.91-6.32). Median OS was 13 years (0.95 CI 7.24-NR) and median RFS was 4.1 years (0.95 CI 3-4.96) for the entire cohort. Baseline comparison between the two groups is shown in table_1. After PSM, Median RFS for Ara-c group was 4.8 (IQR=1.8-16.2) yrs VS 3.6 (IQR=1.52-7) yrs for non-Ara-c group (P value 0.03). However, after censoring on ASCT, median RFS for Ara-c group was 4.7 (IQR 1.5-16.2) yrs VS 3.3 (IQR 1.5-6.9) yrs (P value 0.16). Median OS for Ara-c group was 16.2 yrs (IQR=4.3-16.2) vs 12.95 yrs (IQR=3.7-17.8) for non-Ara-c group (P value 0.5), which was the same after censoring on ASCT. Conclusions: In our cohort, cytarabine use in induction chemotherapy for MCL was associated with longer RFS and OS but it did not reach statistical significance. Larger scale studies are warranted to confirm these results. Of note, older and less fit patients received less cytarabine. Cytarabine Other P value Age 64 (57-69) 69 (63-77) 0.013 Eastern Cooperative group 0,1 96% 84% 0.05 MIPIc 7.56 (6.89-7.92) 8.28 (6.97-9.66) 0.01 Consolidation with ASCT 42% 13% <0.01