Achievement of Remission Endpoints with Secukinumab Over 3 Years in Active Ankylosing Spondylitis: Pooled Analysis of Two Phase 3 Studies

Introduction: Clinical remission in patients with ankylosing spondylitis (AS) has been determined using composite indices such as the AS Disease Activity Score inactive disease (ASDAS-ID), Assessment of SpondyloArthritis international Society criteria partial remission (ASAS-PR), and low Bath AS Disease Activity Index (BASDAI) scores. The objective of this exploratory analysis was to evaluate the proportion of secukinumab-treated patients with AS achieving remission defined based on the ASDAS-ID (score < 1.3), ASAS-PR or BASDAI score ≤ 2.

Methods: The analysis pooled data from the MEASURE 1 and 2 studies over 3 years. The proportion of patients who achieved ASDAS-ID, ASAS-PR, or BASDAI ≤ 2 with secukinumab was compared with placebo at week 16; results for secukinumab-treated patients were summarized through week 156. Sustainability of each criterion was assessed from week 16 to 156 using shift analysis. The association between each of these criteria and specific patient-reported outcomes (PROs), such as health-related quality of life, function, fatigue, and work impairment, was also explored.

Results: At week 16, a higher proportion of secukinumab-treated patients versus placebo achieved ASDAS-ID (17.6 vs. 3.5%), ASAS-PR (15.4 vs. 4.1%), or BASDAI ≤ 2 (22.3 vs. 6.4%) criteria (all P < 0.0001), which were sustained through 156 weeks. Shift analysis showed that the majority of secukinumab-treated patients achieving remission at week 16 maintained their status at week 156 (ASDAS-ID, 57.1%; ASAS-PR, 68.0% and BASDAI ≤ 2, 74.3%). Remission was also associated with improved PROs over 156 weeks.

Conclusions: Secukinumab-treated patients maintained ASDAS-ID, ASAS-PR, or BASDAI ≤ 2 from week 16 up to 3 years. Patients who achieved at least one of the three responses/states, reported improvement in PROs, which suggests an association of clinical remission/ID with PROs in patients with active AS.

Trial registration: ClinicalTrials.gov: NCT01358175NCT01863732, and NCT01649375.

Keywords: Ankylosing spondylitis; Axial spondyloarthritis; Biologics; Interleukin-17; Low disease activity; Patient-reported outcomes; Remission; Secukinumab.