ASAS40 and ASDAS clinical responses in the ABILITY-1 clinical trial translate to meaningful improvements in physical function, health-related quality of life and work productivity in patients with non-radiographic axial spondyloarthritis

Objective. To assess the impact of achieving Assessment in SpondyloArthritis international Society 40% (ASAS40) response or an Ankylosing Spondylitis Disease Activity Score inactive disease (ASDAS-ID) state on patient-reported outcomes (PROs) among patients with non-radiographic axial SpA (nr-axSpA). Methods. Data are from ABILITY-1, a phase 3 trial of adalimumab vs placebo in nr-axSpA patients. PROs included the HAQ for Spondyloarthropathies (HAQ-S), 36-item Short Form Health Survey (SF-36) physical component summary (PCS) score and Work Productivity and Activity Impairment Questionnaire. Patients were grouped by clinical response using ASAS40 response and ASDAS disease states at week 12. Changes in PROs from baseline to week 12 were compared between groups using analysis of covariance with adjustment for baseline scores. Results. At week 12, 47 of 179 patients were ASAS40 responders and 26 of 176 patients achieved ASDAS-ID (ASDAS <1.3). Compared with non-responders (n = 132), ASAS40 responders (n = 47) had a significantly greater improvement in mean HAQ-S (–0.65 vs -0.05, P < 0.0001), SF-36 PCS (12.4 vs 0.7, P < 0.0001), presenteeism (–24.7 vs -2.2, P < 0.0001), overall work impairment (–23.9 vs -2.5, P < 0.0001) and activity impairment (–33.5 vs -0.9, P < 0.0001) at week 12. Similarly, ASDAS-ID, ASDAS clinically important improvement (ASDAS-CII; improvement >1.1) and major improvement (ASDAS-MI; improvement >2.0) were associated with significantly greater improvements from baseline in the majority of the PROs. Conclusion. Among nr-axSpA patients, ASAS40, ASDAS-CII and ASDAS-MI response and achievement of ASDAS-ID were associated with statistically significant and clinically meaningful improvements in physical function, health-related quality of life and work productivity in a higher percentage of patients.