Long-term efficacy and safety of secukinumab 150 mg in ankylosing spondylitis: 5-year results from the phase III MEASURE 1 extension study

Objective This study aimed to report end-of-study results on efficacy and safety of secukinumab 150 mg through 5 years in patients with ankylosing spondylitis (AS; MEASURE 1 extension trial (NCT01863732)). Methods After the 2-year core trial, 274 patients receiving subcutaneous secukinumab 150 or 75 mg (following intravenous loading or initial placebo treatment to 16/24 weeks) every 4 weeks were invited to enter the 3-year extension study. Dose escalation from 75 to 150 mg (approved dose) was allowed at or after week 156 based on the judgement of the treating physician. Assessments at week 260 (5 years) included Assessment of SpondyloArthritis international Society (ASAS) 20/40 and other efficacy outcomes. Data are presented as observed. Safety assessment included all patients who received ≥1 dose of study treatment. Results Of the 274 patients who entered the extension study, 84% (230/274) completed 5 years of treatment. ASAS20/40 responses were 78.6/65.2%, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) 50 response was 63.4% and mean (±SD) BASDAI total score was 2.6±1.76 with secukinumab 150 mg at 5 years. Improvements in efficacy outcomes were sustained through 5 years. A total of 82 patients on secukinumab 75 mg (56.2%) had their dose escalated to 150 mg after week 168; ASAS40, ASAS-PR, ASAS 5/6 and BASDAI50 responses were improved in patients whose dose was escalated from secukinumab 75 to 150 mg. Secukinumab was well tolerated with a safety profile consistent over the course of the study. Conclusions Secukinumab 150 mg provided sustained efficacy across multiple domains of AS with a favourable and consistent safety profile through 5-year treatment. Over 50% of patients required dose escalation from 75 to 150 mg and efficacy improved in these patients.