Abstract 382: Longitudinal C-reactive protein (CRP) as an individualized dynamic predictor for metastatic cancer patients treated with immune checkpoint inhibitors: Findings from the prospective ST-ICI cohort

Background: Numerus studies already proved C-reactive protein (CRP) in pre-treat is a predictive biomarkers to for cancer patients treated with anti-PD(L)-1 antibodies. However, there aren9t any study has evaluated CRP levels longitudinally in patients with immune checkpoint inhibitors (ICIs). This study provides a comprehensive investigation of CRP levels as well as its longitudinal trajectories as a dynamic predictor of treatment response and survival outcome in metastatic cancer patients undergoing immunotherapy with anti PD-1 or anti PD-L1 agents. Methods: A total number of 104 patients were prospectively enrolled. First, multivariate survival analysis for clinical factors, which including cancer types, line of treatment, PD-L1 expression, brain metastases (BM), etc. Then, used multivariate joint modelling of longitudinal and time to event data to establish the relationship between longitudinal CRP and the overall survival (OS). Results: 92/102 patients with more than 2 times CRP results in all of treatment timepoints. Longitudinal CRP levels combine with clinical factors emerged as independent predictors of worse OS (HR of jointed model= 1.82, 95% CI: 1.45-2.32, p Conclusion: Our study highlights longitudinal CRP serves as potential personalized dynamic predictions for immunotherapeutic benefit of metastatic cancer patients. Keywords: metastatic cancers, immune checkpoint inhibitors, C-reactive protein, dynamic predictor Trial registration: Prospectively registered in ClinicalTrials.gov (NCT03453892) on January 24, 2018. Citation Format: Jian-Guo Zhou, Hu Ma, Udo Gaipl, Benjamin Frey, Markus Hecht, Rainer Fietkau. Longitudinal C-reactive protein (CRP) as an individualized dynamic predictor for metastatic cancer patients treated with immune checkpoint inhibitors: Findings from the prospective ST-ICI cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 382.