Impact of C-reactive Protein Flare Response in Patients With Advanced Urothelial Carcinoma Who Received Pembrolizumab.

BACKGROUND/AIM:To clarify the clinical significance of the temporary elevated C-reactive protein (CRP) levels followed by a decrease below baseline (CRP flare response) after administration of pembrolizumab to patients with advanced urothelial carcinoma (UC). PATIENTS AND METHODS:We retrospectively reviewed 31 patients with advanced UC who received pembrolizumab. Patients were categorized into 3 groups (flare-responder, responder, non-responder) according to early CRP kinetics. Intergroup tumor response and survivals were compared. RESULTS:Objective response rates of flare-responder, responder, and non-responder groups were 75%, 80%, and 26%, respectively. Median overall survival was not reached in flare-responder and responder groups, and was 10.2 months in the non-responder group (p=0.03). Furthermore, the flare-responder group did not reach median progression-free survival, and for the responder and non-responder groups it was 15.2 and 2.8 months, respectively (p=0.03). CONCLUSION:CRP flare response might be a promising biomarker in patients with advanced UC who received pembrolizumab.