C-Reactive Protein Kinetics as Prognostic Biomarkers in Stage IV-Melanoma Treated With Immune Checkpoint Inhibitors in the Japanese Population: A Single-Center, Retrospective Cohort Study.

This retrospective study evaluated the prognostic significance of early changes in serum C-reactive protein (CRP) levels in 123 Japanese patients with stage IV melanoma undergoing first-line immune checkpoint inhibitor therapy.

Patients were categorized into four groups based on CRP kinetics during the first 3 months:

• Normal
• Flare
• Responder
• Non-responder

Results showed that the normal and flare groups had higher objective response and disease control rates, as well as longer progression-free and overall survival compared to non-responders.

Multivariate analysis identified CRP kinetics as an independent predictor of survival outcomes.

The findings suggest that early monitoring of CRP levels is a practical, cost-effective biomarker to predict immunotherapy response. This reflects tumor-immune interactions and may help guide treatment decisions.

This study is the first to validate this approach in a Japanese cohort, supporting further research to confirm its utility across diverse populations.