Association of lymphocyte to monocyte ratio with clinical response and survival in patients with relapsed, aggressive non-Hodgkin lymphoma treated with axicabtagene ciloleucel CAR-T.

Abstract

3028 Background: Chimeric antigen receptor T-cell (CAR-T) therapy induces complete remission (CR) in 30-40% of patients with non-Hodgkin lymphoma (NHL). However, for patients who do not achieve CR as their first response, predictors for achieving CR as best response can guide management between careful observation or early intervention. Increased absolute lymphocyte count to absolute monocyte count ratio (ALC/AMC) predicts better response rates and survival in NHL patients receiving chemotherapy and/or autologous stem cell transplant. We evaluated the prognostic impact of ALC/AMC in CAR-T therapy for NHL. Methods: This was a retrospective review of patients who received CAR-T for NHL from June 2016-August 2019. ALC/AMC was assessed at the start of lymphodepletion (LD) chemotherapy. The receiver operator curve (ROC) was used to determine the best cutoff for ALC/AMC in predicting CR at 3 months. Event-free survival (EFS) was defined from time of CAR-T infusion to relapse or death, whichever occurred first. Overall survival (OS) was defined from time of infusion to death of any cause. Results: Forty-seven patients received axicabtagene ciloleucel, with a median follow-up of 14 months. By ROC, ALC/AMC > 0.8 before LD chemotherapy was predictive of achieving CR at 3 months. Baseline characteristics were similar between the high (n = 30) and low (n = 17) ALC/AMC groups. Patients with an ALC/AMC > 0.8 at the time of LD chemotherapy were more likely to achieve CR at 3 months (46% vs. 12%, p = 0.01), 6 months (52% vs. 0%, p < 0.0005), and 12 months (42% vs. 0%, p = 0.01). Correspondingly, the EFS and OS were significantly shorter in patients with ALC/AMC≤0.8 vs. those > 0.8 (median EFS: 2 vs. 13 months, P < 0.0001) and (median OS: 15 months vs. not reached, P = 0.03), respectively. Association between ALC/AMC ratio and EFS and OS remained consistent in multivariate Cox models after adjusting for other prognostic variables, including abnormal lactate dehydrogenase and increased ferritin level at infusion day. Conclusions: ALC/AMC > 0.8 before lymphodepletion chemotherapy is a strong predictor for complete remission as well as improved event-free and overall survival for axicabtagene ciloleucel in NHL.