Long-term efficacy and predictors of remission following adalimumab treatment in peripheral spondyloarthritis: 3-year results from ABILITY-2

Objectives Describe efficacy and safety of 3 years of adalimumab treatment in patients with peripheral spondyloarthritis (pSpA) and identify predictors of remission. Methods Patients with pSpA were randomised to adalimumab 40 mg every other week or placebo for 12 weeks; a 144-week open-label extension followed (NCT01064856). Remission was assessed by the Peripheral SpA Response Criteria (PSpARC) and Ankylosing Spondylitis Disease Activity Score inactive disease (ASDAS ID). Logistic regression analyses were performed to determine predictors of remission at 1 and 3 years and sustained remission (≥24 consecutive weeks). Results In 165 patients, ASDAS ID was achieved by 47% at 1 year and 39% at 3 years; 36% and 33% achieved PSpARC remission, respectively. Sustained ASDAS ID and PSpARC remission were achieved by 52% (86/165) and 42% (70/165) of patients, respectively. Achieving ASDAS ID at week 12 significantly predicted 1 year (OR, 8.64 (95% CI 2.97 to 25.14)), 3 year (OR, 36.12 (95% CI 2.29 to 569.08)) and sustained ASDAS ID (OR, 8.01 (95% CI 2.47 to 25.97)); achieving PSpARC remission at week 12 consistently predicted 1 year (OR, 6.47 (95% CI 1.91 to 21.95)), 3 years (OR, 15.66 (95% CI 4.19 to 58.56)) and sustained PSpARC remission (OR, 20.27 (95% CI 5.37 to 76.46)). No baseline variables consistently predicted 1-year or 3-year remission or sustained remission. The safety profile of adalimumab was consistent with observations in other SpA disease indications. Conclusions In patients with pSpA, early response to adalimumab, but not baseline demographics or disease characteristics, was a better predictor of long-term remission.