FRI0398 Pharmacologic Therapy and Radiographic Progression in Ankylosing Spondylitis: A Growing Controversy

Background Pharmacologic therapies in Ankylosing Spondylitis (AS) have informed debatable effects on radiographic progression. Two-year studies using Tumor Necrosis Factor inhibitors (TNFi) showed no benefit, yet longer-term studies reported less radiographic progression. Similarly, NSAID effects have been controversial. Objectives To determine the relationship between pharmacologic therapies and radiographic progression in AS. Methods This is a prospective cohort of 505 AS patients meeting the modified New York criteria with at least 2 years of radiographic follow up. Using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), progressors were defined with at least one mSASSS unit increase per year of follow up or patients who rapidly progressed at any time point (2 new syndesmophytes in 2 years). Patients with an mSASSS=72 at baseline (n=17) were excluded. TNFi use was defined at each 6-month study visit and adjusted for baseline use and total duration of use. High NSAID use was defined if the patient was taking NSAIDs at least 50% of the study period. We grouped patients according to their follow-up period (interval between baseline and last visit) and used progressor status (progressor vs. non-progressor) as a dichotomized outcome in univariable and multivariable mixed effects logistic regression models. Results The progressors made up 35.45% of the cohort (n=179). We found that TNFi use was related to a lower likelihood of radiographic progression and this association appeared to be strongest for patients with 2.1–3.5 years of follow-up (OR=0.25, 95% CI 0.07,0.92; p=0.0376). Although not statistically significant, in patients who were followed up for 3.6 years or longer, the odds of progression for the TNFi user group was 46% lower in the 3.6–5.9 year group (OR=0.54) and 23% lower in the 6+ year group (OR=0.77) than in TNFi non-users. Patients exposed to NSAIDs (≥50% exposure) also had a lower likelihood of radiographic progression (OR=0.47, 95% CI 0.22,0.99); p=0.046) [Table 1]. The probability of progression by years of follow up per TNFi user group is shown in Figure 1. Conclusions TNFi use is associated with a lower likelihood of radiographic progression in AS with the most significant effect after longer than 2 years of follow up. Use of NSAIDs was also associated with less radiographic progression. Disclosure of Interest L. Gensler Consultant for: AbbVie, Amgen, Janssen, Novartis, UCB, J. Reveille: None declared, M. Ward: None declared, M. Brown Grant/research support from: Janssen, Abbvie, UCB, Leo Pharma, Complete Genomics, Consultant for: Abbvie, UCB, Janssen, Pfizer, Speakers bureau: Abbvie, UCB, Pfizer, UCB, M. Rahbar: None declared, M. Lee: None declared, M. Weisman Grant/research support from: UCB, Human Genome Sciences, Sanofi, Eli Lilly and Co, Genentech, Inc., Santarus Inc., EMD Serono, ChemoCentryx, GSK, Immunomedics Inc., Consultant for: Boehringer Ingelheim/Proskauer, Ardea Biosciences, Epirus Biopharmaceuticals, Acerta Pharma