OP0024 What happens to patients with ankylosing spondylitiswho start a first biologic? a swedish study of treatment trajectories in clinical practice

Background Clinical trials have shown that 40%–50% of patients with ankylosing spondylitis (AS) achieve a good response (≥40% improvement) to treatment with tumour necrosis factor inhibitors (TNFi). By contrast, observational studies indicate that less than two out of three patients continue their first biological disease modifying anti-rheumatic drug (bDMARD) up to two years. During the past six years, five TNFi and one IL-17-inhibitor have been marketed for AS in Sweden. Yet, an assessment of long-term treatment trajectories in AS is lacking. In particular, there is a need for a better understanding of the proportion of patients who fail their first bDMARD, when this happens, and which drugs become their ensuing treatments. Objectives To describe contemporary five-year treatment trajectories for patients initiating a first ever bDMARD in AS, and to explore whether the dose of bDMARD is gradually tapered in those patients who remain stable on their bDMARD treatment. Methods Swedish patients with AS starting a first ever bDMARD in 2010–2015 were identified in the Swedish Rheumatology Quality Register (SRQ). At the end of each full year (1–5 years) after treatment start, the treatment status of each patient was determined. Censoring occurred at the first of: death, emigration, 31 December 2015 or loss to follow-up. In addition, data on collected prescriptions for the subcutaneous bDMARDs were retrieved form the National Prescribed Drug Register. For patients remaining on their first subcutaneous bDMARD, according to SRQ, the proportion of patients collecting ≥75% of the yearly ‘defined daily doses’ (DDD) at a pharmacy during each full year was determined. Results 1698 patients with AS starting a first bDMARD in the study-period were identified, all of which were TNFi. After the end of the first year, 74% remained on their first bDMARD and after five years 38% (figure 1). Of the 72% of patients who remained on any bDMARD after five years, 85% were on their first or second bDMARD. After five years 24% were not on any DMARD and around five percent of the patients discontinuing bDMARD treatment did so due to low disease activity or remission. Among those remaining on their first subcutaneous bDMARD the proportion collecting ≥75% of the yearly DDD gradually decreased from 88% to 56% over the 5 years of follow-up (black line in figure 1). Conclusions While a minority of patients with AS remain on their first-line bDMARD after 5 years of treatment, most are still on any bDMARD. Further, despite a low rate of discontinuation due to remission, one fourth of patients no longer use any bDMARDs treatment after 5 years. Patients remaining stable on treatment gradually but substantially decrease their use over time. Disclosure of Interest U. Lindstrom: None declared, T. Olofsson: None declared, S. Wedren: None declared, I. Qirjazo: None declared, J. Askling Grant/research support from: JA has received grants from Abbvie, BMS, Merck, Pfizer, Roche, Samsung, UCB, mainly for safety monitoring via the Swedish ARTIS system