Effect of Certolizumab Pegol Over Ninety-Six Weeks in Patients With Axial Spondyloarthritis: Results from a Phase III Randomized Trial

OBJECTIVE: Previous reports of the RAPID-axSpA trial (NCT01087762) described the efficacy and safety of certolizumab pegol (CZP) over 24 weeks in patients with axial spondyloarthritis (SpA), including ankylosing spondylitis (AS) and nonradiographic axial SpA. We report efficacy and safety data up to week 96 of the study. METHODS: The RAPID-axSpA trial is double-blind and placebo-controlled to week 24, dose-blind to week 48, and open-label to week 204. Outcome variables included Assessment of SpondyloArthritis international Society criteria for 20% and 40% improvement in disease activity (ASAS20/40), ASAS partial remission responses (analyzed by nonresponder imputation), AS Disease Activity Score (ASDAS), ASDAS inactive disease, ASDAS major improvement, Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), and Bath AS Metrology Index (BASMI) linear score (analyzed by the last observation carried forward method). Safety data were collected for patients treated with ≥1 dose of CZP. RESULTS: Of the 325 patients who were randomized, 218 received CZP from week 0. Of these, 93% completed week 24, 88% completed week 48, and 80% completed week 96. Improvements in ASAS responses were maintained to week 96 (for ASAS20, 67.4%, 72.0%, and 62.8% at weeks 24, 48, and 96, respectively), as well as improvements in ASDAS, BASDAI (mean score 3.3, 3.1, and 3.0 at weeks 24, 48, and 96, respectively), BASFI, and BASMI linear score. Comparable improvements were observed with both dosing regimens (200 mg every 2 weeks or 400 mg every 4 weeks) and in patients with AS and those with nonradiographic axial SpA. In the safety set, adverse events occurred in 279 patients (88.6%) and serious adverse events in 41 (13.0%). No deaths or malignancies were reported. CONCLUSION: Clinical improvements to week 24 in both CZP dosing regimens were sustained to week 96. Similar sustained improvements were observed in AS and nonradiographic axial SpA subpopulations. The safety profile was consistent with previous reports from RAPID-axSpA, with no new safety signals observed with longer exposure.