Early C-reactive protein kinetics predict survival of patients with advanced urothelial cancer treated with pembrolizumab

Objective: To assess the prognostic and predictive ability of early C-reactive protein (CRP) kinetics, dynamic changes in CRP levels, in patients with advanced urothelial cancer treated with pembrolizumab. Patients and methods: We retrospectively evaluated 97 patients with advanced urothelial cancer treated with pembrolizumab in second-line or later settings. Patients were divided into three early CRP kinetics groups: non-elevated (baseline CRP < 5 mg/L), responder (baseline CRP ≥ 5 mg/L and CRP decreased below baseline at least once within 30 days), and non-responder (baseline CRP ≥ 5 mg/L and CRP never decreased to baseline within 30 days). Association between early CRP kinetics and pembrolizumab efficacy including objective response rate (ORR), disease control rate (DCR), and overall survival (OS) were evaluated. Results: Based on early CRP kinetics, 40, 27, and 30 patients were classified as non-elevated, responder, and non-responder, respectively. ORR and DCR were 33% and 60% in non-elevated, 30% and 48% in responder, and 17% and 40% in non-responder; without a statistically significant difference. OS was significantly different among the non-elevated, responder, and non-responder groups (p < 0.01), with 1-year survival rates of 69%, 61%, and 31%, respectively. Early CRP kinetics could discriminate the OS of patients without objective response. Non-responder was an independent predictor for OS (HR 3.65, p < 0.01), as well as liver metastasis and ECOG PS ≥ 2. Conclusion: Early CRP kinetics is associated with survival of advanced urothelial cancer patients treated with pembrolizumab and could be a potential biomarker for clinical benefit from immune checkpoint inhibitors.