The change of serum C-reactive protein levels during molecular-targeted treatments could predict the response to anti-PD-1 treatment in metastatic renal cell carcinoma patients.

Abstract

e17085 Background: Immuno-oncology (IO) checkpoint inhibitors, such as programmed death-1/programmed death-ligand1 (PD-1/PD-L1) inhibitors have been standard of care in the metastatic renal cell carcinoma (mRCC) systemic treatment. However, predictive biomarkers for IO checkpoint inhibitors which is clinically usable have been still unclear. The aim of this study was to evaluate the clinical significance of the change of serum C-reactive protein (CRP) levels during molecular-targeted treatments (VEGFR-TKI and mTOR-I) prior to nivolumab as the predictive marker for the response of nivolumab in patients with refractory mRCC. Methods: A total of 73 mRCC patients (favorable 25(34%), Intermediate 38(52%) and poor 10(14%) risk group by IMDC criteria) treated with nivolumab were retrospectively reviewed. We evaluated the serum CRP levels before and after molecular-targeted treatments. The elevation of serum CRP during molecular-targeted therapies before nivolumab induction was defined as the CRP-elevation group. The clinical impact of CRP-elevation as well as other clinical and pathological prognostic factors on progression-free survival (PFS) and overall survival (OS) from nivolumab were assessed. Results: The median follow-up period after nivolumab initiation was 13.2 months (range 3.0-60.8). Forty-nine patients (67%) were categorized into the CRP-elevation group. A clear impact of the CRP-elevation on the response of nivolumab was observed: the median PFS of the CRP-elevation group was 11.9 months, and that of the CRP-non elevation was not-reached (p = 0.038). On multivariate analysis, the CRP-elevation before nivolumab was the independent prognostic factor to predict PFS in nivolumab treatment (HR: 2.68, 95% CI: 1.01-7.11, p = 0.047). CRP-elevation group had a tendency of shorter OS than CRP-non elevation group (p = 0.071). Conclusions: The change of serum CRP levels during molecular-targeted therapies could be the predictive factor for the efficacy of nivolumab in mRCC patients.