Abstract 113P
Background
Biomarkers for predicting response to immune checkpoint inhibitors (ICI) are scarce and often lack external validation. This retrospective bi-center study provides a comprehensive investigation of pretreatment C-reactive protein (CRP) levels and its longitudinal trajectories as a marker of treatment response and disease outcome in patients with advanced non-small cell lung cancer (NSCLC) undergoing immunotherapy with anti PD-1 or anti PD-L1 agents.
Methods
Primary treatment outcomes were progression-free survival (PFS) and overall survival (OS), while the objective response rate (ORR) was a secondary outcome, respectively. Joint models were implemented to evaluate the association of longitudinal CRP trajectories and progression risk.
Results
In the discovery cohort (n=90), elevated pre-treatment CRP emerged as independent predictor of worse PFS (HR per doubling of baseline CRP=1.37, 95%CI: 1.16-1.63, p<0.0001), worse OS (HR per doubling of baseline CRP=1.42, 95%CI: 1.18-1.71, p<0.0001) and a lower ORR ((Odds Ratio (OR) of ORR per doubling of baseline CRP=0.68, 95%CI: 0.51-0.92, p=0.013)). In the validation cohort (n=101), pre-treatment CRP could be confirmed as a predictor of PFS and OS, but not ORR. Elevated trajectories of CRP during anti PD-(L)1 treatment (Adjusted HR per 10mg/L increase in CRP=1.22, 95%CI: 1.15-1.30, p<0.0001), as well as a faster increases of CRP over time (HR per 10mg/L/month faster increase in CRP levels =13.26, 95%CI: 1.14-154.54, p=0.039) were strong predictors of an elevated progression risk, whereas an early decline of CRP was significantly associated with a reduction in PFS risk (HR=0.91, 95%CI: 0.83-0.99, p=0.036), respectively.
Conclusions
These findings warrant that CRP should be further explored by prospective studies as a non-invasive biomarker for assessing treatment benefit during anti PD-(L)1 treatment in advanced NSCLC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.