P253 Secukinumab provides sustained improvements in tender and swollen joint counts: 5year results from the Phase 3 FUTURE 2 study

Abstract Background Secukinumab, a fully human monoclonal antibody that neutralises interleukin-17A, demonstrated long-term efficacy and tolerability in psoriatic arthritis (PsA) patients in FUTURE 2. Tender joint count (TJC) and swollen joint count (SJC) scores are components of composite measures used to assess treatment response, which can include confounding factors. TJC and SJC were developed for rheumatoid arthritis, assessing 68 and 66 joints, respectively. Later, these scores evolved for use in PsA, which can affect small joints of the feet, assessing 78 and 76 joints. TJC and SJC measure synovitis, a key assessment of disease activity. Herein, we report the 5-year efficacy of secukinumab on reduction of 78 TJC and 76 SJC in FUTURE 2. Methods 397 patients with active PsA were randomised to subcutaneous secukinumab loading dose (300, 150, 75 mg) or placebo at baseline, Weeks 1, 2, 3 and 4, and every 4 weeks thereafter. Placebo-treated patients were re-randomised to secukinumab 300 or 150 mg at Week 16 (non-responders) or 24 (responders). Secukinumab dose was escalated from 150 to 300 mg, and 75 to 150 or 300 mg starting at Week 128 and maintained thereafter, if active signs of disease were observed based on physician’s assessment. Data are reported as observed for secukinumab 300 and 150 mg (approved PsA doses) over 5 years (2 years of core study and 3-year extension). Results Baseline characteristics were comparable across treatment arms (Table 1). Overall, 62.5% (248/397) of all patients randomised completed 260 weeks of treatment. Of these, 48/65 (73.8%) and 49/66 (74.2%) patients randomised to secukinumab 300 and 150 mg achieved ACR20 at Week 260, respectively. Improvements in adjusted 78 TJC and 76 SJC change from baseline were sustained from Week 16 to Week 260 in all treatment groups (Table 1). At Week 260, mean change from baseline in adjusted 78 TJC/76 SJC was −12.8/−9.3 and −15.1/−8.5 for the secukinumab 300 mg and 150 mg group (including patients up-titrated to 300 mg), respectively. Numerical differences were comparable between secukinumab doses. P253 Table 1: Selected baseline characteristics and 78 TJC/76 SJC results at Weeks 16 and 260 Baseline characteristics Variable SEC 300 mg SC(n = 100) SEC 150 mg SC(n = 100) PBO (n = 98) Mean age, years 46.9 46.5 49.9 Sex, n (%) Male 51 (51.0) 55 (55.0) 39 (39.8) Mean weight, kg 85.4 91.2 86.2 Smoking status, n (%) No 81 (81.0) 79 (79.0) 81 (82.7) Mean time since first diagnosis of PsA, years 7.