Bimekizumab Improves Spinal Pain, Fatigue, Morning Stiffness in axSpA

Patients with axial spondyloarthritis (axSpA) treated with bimekizumab who had a high disease burden at baseline had clinically meaningful improvements in symptoms including morning stiffness, fatigue, and spinal pain. These results were discussed in the post hoc analysis “Bimekizumab Treatment Improved Key Patient-Reported Symptoms of Axial Spondyloarthritis Including Spinal Pain, Fatigue, and Morning Stiffness: 52-Week Results from Two Phase 3 Studies.”

Previously, the phase 3 BE MOBILE 1 and BMOBILE 2 trials reported sustained improvements to week 52 in patients with active non-radiographic (nr-) and radiographic axial spondyloarthritis (r-axSpA) receiving the monoclonal IgG1 antibody, bimekizumab.

At the American College of Rheumatology’s 2023 Convergence, held last week in San Diego, California, Philip Mease, MD, clinical professor at the University of Washington School of Medicine and director of Rheumatology Research at the Swedish Medical Center in Seattle, and colleagues, reported on the impact of the drug in this patient population on patient-reported symptoms.¹

Both trials included a 16-week double-blind period followed by a 36-week maintenance period. Participants were randomized to receive either subcutaneous bimekizumab 160 mg every 4 weeks (Q4W) or placebo. At week 16, all subjects received bimekizumab.

This presentation focused on mean change from baseline in Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scores, nocturnal and total spine pain, and morning stiffness according to Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), as evaluated by the mean of BASDAI questions 5 and 6. The least squares means difference (LSMD) was reported for FACIT-F at week 16. Additionally, the proportion of patients who achieved low levels of pain, defined as the total and nocturnal spinal pain scores of ≤2 and ≤4, respectively, as well as a meaningful improvement in fatigue, defined as a ≥8-point increase from baseline in FACIT-F score, were analyzed post hoc.

A total of 332 patients with r-axSpA, of which 221 received bimekizumab and 111 received placebo, and 254 patients with nr-axSpA, of which 128 received bimekizumab and 126 received placebo, were included in the analysis. Among both nr-axSpA and r-axSpA groups, 86.6% (n = 220/254) and 89.8% (n = 298/332) of patients completed the entire 52-week period, respectively. Mean baseline scores demonstrated patients had high disease burden.

At the 16-week mark, patients treated with bimekizumab reported greater improvements in both mean nocturnal and total spine pain, as well as BASDAI-related morning stiffness when compared with placebo (P <.001). These mean scores were further improved through week 52 in bimekizumab-treatment patients as well as among patients who switched from placebo to bimekizumab at week 16. Interestingly, responses from the switch cohort were comparable to patients who were initially randomized to the treatment arm. Similarly, more patients in the bimekizumab group obtained low nocturnal and total spine scores, of which improvements were comparable across the switch group and those randomized to bimekizumab.

At week 16, patients in the bimekizumab cohort achieved greater improvements in FACIT-F scores compared with placebo (mean change from baseline [CfB]: nr-axSpA: 8.5 vs 3.9; r-axSpA: 8.4 vs 5.0), with similar results among the initial treatment group and those who switched (mean CfB: nr-axSpA: 10.9 vs 9.2; r-axSpA: 9.9 vs 9.5). A higher proportion of patients in the bimekizumab group were able to achieve ≥8-point improvement from baseline when compared with placebo at week 16, which were similar among both groups at week 52.

“These findings emphasize the benefit of bimekizumab on clinical symptoms which are important to pts and have a substantial impact on their daily lives,” investigators concluded.

Reference

1. ^{Mease P, Dougados M, Dubreuil M, Nighat Magrey M, et al. Bimekizumab Treatment Improved Key Patient-Reported Symptoms of Axial Spondyloarthritis Including Spinal Pain, Fatigue, and Morning Stiffness: 52-Week Results from Two Phase 3 Studies. Presented at: American College of Rheumatology Convergence 2023. San Diego, CA. November 10-15, 2023.}