Background While data on real-life SEC retention rate in patients (pts) with axSpA is accumulating, there are few data on predictive factors for this retention. Presence of objective sign of inflammation (OSI), especially increased baseline CRP level, is known to be predictive of efficacy of anti-TNFs and their retention in axSpA.

Objectives To assess whether OSI, especially increased baseline CRP level, were predictive of SEC retention at 1 year in axSpA.

Methods French retrospective study collecting between October 2019 and September 2020 data from axSpA pts a) having initiated and received at least one dose of SEC between August 11^th 2016 and August 31^st 2018, b) with at least a one-year follow-up period. Retention rate of SEC at 1 year was estimated by the Kaplan Meier (KM) method. OSI were defined by at least one of the following: CRP ≥5 mg/l or ESR ≥28 mm/h if CRP not available (CRP+) within the 3 months before initiation of SEC and MRI inflammation at the sacroiliac or spine level (MRI+) at any time. The a priori selected potential predictive factors of the SECU 1 year retention (CRP+, MRI+, age, sex, BMI, smoking, HLA B27, non-radiographic vs radiographic axSpA, past or present uveitis/Inflammatory Bowel Disease/psoriasis/arthritis or synovitis, diagnostic delay, disease duration, SEC line of biologic therapy, SEC maintenance dose, concomitant csDMARD/oral corticosteroids/proton pomp inhibitor at SEC initiation, history of depression/fibromyalgia) were analyzed by cox model regression. Only variables with <20% missing data were included in the model after imputation and stepwise selection (significance level for entering variables =20%; significance level for removing variables =10%), except for CRP and MRI which were forced into the model whatever their significance level or rate of missing data.

Results In total, 906 pts from 47 centers (male: 42.2%, mean age: 46.2 ± 11.7 years, mean disease duration: 9.3 ± 9.1 years) were included in the analysis. The mean baseline CRP (± SD) was 11.1 ± 17.5 mg/L. At initiation of SEC, 86.3% of pts had ≥ 1 OSI (41.3% CRP+, and 69.4% MRI+) and respectively 8.0%, 14.9% and 77.1% were in 1^st, 2^nd and ≥ 3^rd line (L) of biologic/targeted synthetic DMARD. The 1-year retention rate for SEC was 59% [95%CI: 55%-62%]. This retention at one year was 62.4% vs 59.1% and 57.4% vs 66% in patients with CRP+ vs CRP- and MRI+ vs MRI- respectively. In univariate cox regression, CRP+ was not predictive of SEC discontinuation at 1 year (HR = 0.90 [0.71-1.16]; p=0.422 nor was MRI+ (HR=1.29 [0.99; 1.68]; p=0.063). In multivariate cox analysis, after adjustment, these results were confirmed for CRP+ but MRI+ was identified as predictive of a worst SEC retention at 1 year (Table 1). In multivariate analysis lack of prior exposure to anti-TNF inhibitors, absence of IBD and absence of history of depression were also associated with a better SEC retention at 1 year (at 10%).

Conclusion The overall retention of SEC at 1 year in daily practice in France was 59% for axSpA patients, independently of CRP level at SEC initiation.

Acknowledgements Authors thank the participating investigators, centers and patients. NOVARTIS Pharma France financially supported this study.

Disclosure of Interests Philippe Goupille Speakers bureau: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Janssen, Lilly, Medac, MSD, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Consultant of: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Janssen, Lilly, Medac, MSD, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Grant/research support from: Abbvie, Biogen, MSD, Pfizer, Maxime Dougados Speakers bureau: Pfizer, Abbvie, Lilly, UCB, Merck, BMS, Roche, Biogen, Sanofi, Novartis, and Sandoz, Consultant of: Pfizer, Abbvie, Lilly, UCB, Merck, BMS, Roche, Biogen, Sanofi, Novartis, and Sandoz, Grant/research support from: Pfizer, Abbvie, Lilly, UCB, Merck, BMS, Roche, Biogen, Sanofi, Novartis, and Sandoz, Audrey Lardy-Cléaud: None declared, Emilie Desfleurs Employee of: Novartis employee, Pascal Claudepierre Speakers bureau: AbbVie, Janssen, Lilly, MSD, Novartis, Pfizer, Consultant of: Abbvie, Pfizer, Roche-Chugai, Bristol-Myers Squibb, MSD, UCB, Novartis, Janssen, Lilly, Celgene, Adeline Ruyssen-Witrand Speakers bureau: AbbVie, Amgen, Biogen, Bristol Myers Squibb, Fresenius-Kabi, Galapagos, Janssen, Lilly, MSD, Mylan, Nordic-Pharma, Novartis, Pfizer, Roche Chugai, Sanofi, and UCB, Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Mylan, Novartis, Pfizer Inc, Sanofi Genzyme, Grant/research support from: AbbVie, Amgen, Mylan, Pfizer Inc, Alain Saraux Speakers bureau: Abbvie, Biogen, Bristol Myers Squibb, Fresenius, Galapagos, GSK, Lilly, Merck Sharp, Nordic, Novartis, Pfizer, Roche-Chugai, UCB, Consultant of: Abbvie, Lilly, Novartis, Pfizer, Grant/research support from: Roche-Chugai, Lilly, Fresenius, Anne Tournadre Speakers bureau: Abbvie, Fresenius, Janssen, MSD, Pfizer, Roche Chugai, Sanofi, Paid instructor for: Fresenius, Consultant of: Abbvie, Fresenius, Lilly, Novartis, Sanofi, Grant/research support from: Fresenius, Novartis, Pfizer, UCB, Cédric Lukas Speakers bureau: Abbvie, Amgen, Janssen, Lilly, MSD, Novartis, Pfizer, Roche-Chugai, UCB, Consultant of: Abbvie, Amgen, Janssen, Lilly, MSD, Novartis, Pfizer, Roche-Chugai, UCB, Grant/research support from: Pfizer, Novartis and Roche-Chugai, Daniel Wendling Speakers bureau: AbbVie, BMS, MSD, Pfizer, Roche Chugai, Amgen, Nordic Pharma, UCB, Novartis, Lilly, Sandoz, Grunenthal, Janssen, Galapagos, Consultant of: Novartis.