Dynamic changes in serum analyte levels associated with clinical outcome in squamous cell lung cancer trial SWOG Lung-MAP S1400I of nivolumab ± ipilimumab.

Abstract

9044 Background: While Immune checkpoint blockade (ICB) is standard treatment for lung cancer there are limited biomarkers that predict benefit, pharmacokinetic on-treatment activity or explain progression. S1400I was a randomized Phase III trial of nivolumab(N)+ipilimumab(I) versus N (NCT02154490, PMID 34264316) for ICB naïve, previously treated stage IV or recurrent squamous cell lung cancer. We performed circulating serum protein analysis of serial blood specimens from patients enrolled in S1400I to evaluate if serum proteins levels changed over time, changes differed by treatment arm, and if they were associated with overall survival. Methods: 561 serial blood specimens (baseline, weeks (wk) 3, 7, 9, and progression [PD]) from 160 of 252 eligible patients enrolled to S1400I were analyzed for 92 immuno-oncology analytes with the Olink proximity extension assay. Protein levels were normalized with use of internal controls and quantified as log2 protein expression (denoted as NPX). Linear mixed models evaluated change in expression from baseline at each time point (wks 3,7,9 and PD), and NPX differences at baseline, wk3, and PD depending on best objective response. A Cox model was used to evaluate the association between baseline NPX and survival. Overall survival and longitudinal cytokine expression were jointly modeled using a linear mixed model to estimate dynamic biomarker changes in NPX and a Cox model for survival. The joint models for time-varying NPX values included a random intercept and modeled time using a natural spline with three knots. Significance was defined as P < 0.05. Results: Serum proteins PCDC1, CXCL9, and CXCL10 were increased from baseline at wks 3,7,9 and at PD. CCL19 was increased at wks 3 and 7 but not at wk 9 and PD. IL10 and IFNγ were increased at wk 3 but subsequently returned to baseline. Change in CXCL13 from baseline to PD was larger for N+I versus N. Baseline CCL23, CSF-1, IL6, and MUC-16 were associated with shorter survival (HR > 1). Joint modeling of survival with cytokines showed an increased risk of death (HR > 1) with higher longitudinal serum levels of CXCL13, MMP12, CSF-1, and IL8. Patients achieving objective response had higher IL4 and LAMP3 and lower IL6 and IL8 at baseline and wk 3 compared to non-responders. Conclusions: Measurements of blood circulating soluble proteins represent easily accessible biomarkers that may be useful as indicators of outcome, and that will need to be prospectively confirmed. Clinical trial information: NCT02154490.