Deciphering differential biomarkers for anti-interleukin-6 receptor and anti-tumour necrosis factor-α treatment...

To identify blood-based predictive and pharmacodynamic biomarkers at different timepoints in patients with active rheumatoid arthritis (RA) treated with anti-interleukin-6 receptor (anti-IL-6R) and anti-tumour necrosis factor-α (anti-TNF-α).

This study used blood samples from the MONARCH trial (NCT02332590), a randomised, double-blind, phase III trial that compared the safety and efficacy of sarilumab (anti-IL-6R) and adalimumab (anti-TNF-α) monotherapy in patients with RA who were intolerant/inadequate responders to methotrexate. The study evaluated predictive biomarkers to anti-IL-6R and anti-TNF-α treatments at baseline and week 2 and pharmacodynamic biomarkers at week 2 and week 24 using Olink proteomics analysis (n=804 serum samples from 268 patients). Change in gene expression levels (n=522 peripheral blood samples from 261 patients) by both treatments was assessed using RNA sequencing analysis.

Serum biomarkers most predictive to anti-IL-6R were different from those of anti-TNF-α; predictive biomarkers for anti-IL-6R were correlated with innate immune activation and synovial inflammation, while predictive biomarkers for anti-TNF-α seemed to be more T-cell and neutrophil-related. For baseline predictive biomarkers, we had to focus on relative prediction as the absolute prediction performance of single and combination biomarkers using cross-validation was limited. Additionally, the pharmacodynamic effects of anti-IL-6R and anti-TNF-α on biomarkers as well as pathway signatures were distinct.

The unbiased analysis of serum proteins identified biomarkers most predictive of anti-IL-6R and anti-TNF-α at different timepoints that could explain the difference in the response rate in patients with RA. Further, both biomarker and pathway results highlighted a differentiated mode of action of both treatments.