OP0106 Effect of Certolizumab Pegol on Signs and Symptoms of Axial Spondyloarthritis, Including Ankylosing Spondylitis and Non-Radiographic Axial Spondyloarthritis: 24-Week Results of Rapid-Axspa Study

Background Axial spondyloarthritis (axSpA) includes both ankylosing spondylitis (AS) and axSpA with no definitive sacroiliitis on X-ray (non-radiographic axSpA, nr-axSpA). RAPID-axSpA (NCT01087762) is the first RCT of an anti-TNF to include both populations. Objectives To report the 24-week (wk) efficacy and assess safety of certolizumab pegol (CZP), a PEGylated Fc-free anti-TNF, in axSpA. Methods The ongoing 158-wk RAPID-axSpA trial was double-blind and placebo (PBO)-controlled to Wk24.1 Recruited pts had adult-onset active axSpA according to the ASAS criteria,2 and included AS pts also meeting the modified New York criteria and nr-axSpA pts. Pts were randomized 1:1:1 to PBO every 2 wks (Q2W), or 400mg CZP at Wk0, 2 and 4 (loading dose) followed by either 200mg CZP Q2W or 400mg CZP every 4 wks (Q4W). The primary endpoint was ASAS20 response at Wk12. Secondary endpoints included ASAS40 and ASAS partial remission responses, and change from baseline (BL) in BASDAI, BASFI, and BASMI linear. Other outcomes included ASDAS major improvement and inactive disease response rates. NRI was used for categorical measures; LOCF was used for continuous measures. Outcomes analyzed in the randomized pt set. Results 325 pts were randomized. BL characteristics were similar between treatment groups. Disease activity was similar between AS and nr-axSpA pts. The primary endpoint, ASAS20 at Wk12, was achieved with clinically and statistically significant improvements in CZP 200mg Q2W and CZP 400mg Q4W arms vs PBO (57.7 and 63.6 vs 38.3, p≤0.004). Significant improvements in ASAS20 were observed as early as Wk1 (40.5 and 34.6 vs 14.0, p