OA02 Longitudinal high throughput proteomics identifies novel proteins associated with inflammation and future response in new-onset, treatment-naïve rheumatoid arthritis

Abstract Background/Aims Despite the availability of effective targeted therapies, only 20-30% achieve low disease activity and even fewer attain remission. There remains a pressing need to identify meaningful biomarkers and disease endotypes to enable precision medicine. We aimed to identify serum protein biomarkers that associate with RA inflammation and future remission in a treatment-naïve, new-onset RA trial cohort. Methods Serum from 105 patients from the ‘VEDERA’ trial (first-line tumour necrosis factor inhibitor + methotrexate [TNFi + MTX] versus methotrexate treat-to-target [MTX-TT]) at baseline, week 24 and 48 were analysed for 92 proteins using the Olink Target 96 Inflammation panel. Clinical and MSUS assessments completed at baseline, weeks 24 and 48 were used for the analyses. Clinical remission was defined as DAS28-ESR ≤ 2.6 and joint-level remission as absence of power Doppler ultrasound synovitis (PDUS). After adjusting for age, gender and seropositive status, Bayesian mixed effects regression (posterior estimates and 95% credible intervals reported) was used to identify association of (i) proteins with clinical disease activity (DAS28-ESR) and joint-level inflammation (total power Doppler ultrasound synovitis (PDUS) scores] and (ii) baseline proteins with future (week 24 or 48) clinical and joint-level remission. Results Longitudinally, out of 92 proteins, 10 and 14 were significantly associated with DAS28-ESR and total PDUS scores respectively, with 3 proteins in common: leukaemia inhibitory factor receptor (LIF-R); fractalkine (CX3CL1); interleukin-10 receptor alpha (IL-10RA). Baseline levels of 9 proteins were associated with future clinical remission (week 24 = 6 proteins; week 48 = 3 proteins) while 6 were associated with future PDUS status (week 24 = 4 proteins; week 48 = 3 proteins). Proteins that were associated with inflammation longitudinally and whose baseline levels associated with future remission included IL-17C, fibroblast growth factor 5 (FGF-5), lymphotoxin alpha and TNF. Posterior estimates and 95% credible intervals for above proteins are reported in Table 1. Conclusion Using longitudinal high-throughput proteomics in a treatment-naïve early onset RA cohort, this study sheds new light on known and novel protein associates of inflammation and future remission. With future validation, these biomarkers could provide mechanistic understanding and allow for individualised treatment strategies to improve outcomes. Disclosure R. Shukla: None. R. Wakefield: None. A. Tan: None. P. Emery: Consultancies; BristolMyersSquibb, AbbVie, Gilead, Galapagos, Eli Lilly, MSD, Pfizer, Novartis, Roche and Samsung. Grants/research support; AbbVie, Eli Lilly, Novartis, BristolMyersSquibb, Pfizer and Roche, outside the submitted work. D. Plant: None. M.H. Buch: Consultancies; AbbVie, Arxx Therapeutics, Boehringer Ingelheim, Galapagos, Gilead, and Pfizer; and speaker fees from AbbVie, CESAS Medical, Galapagos, Gilead, Medistream, and Pfizer. Grants/research support; grant support from Gilead.