Bimekizumab eases pain, morning stiffness in axSpA patients

Treatment with bimekizumab quickly relieves pain and morning stiffness among patients with axial spondyloarthritis (axSpA), as shown in a study. Such improvements persist through week 52.

“[I]nhibition of IL-17A and IL-17F with bimekizumab resulted in rapid, substantial improvements compared with placebo in levels of pain, morning stiffness, and fatigue across the full disease spectrum of axSpA, which were sustained or which continued to improve to week 52,” the investigators said.

In this study, patients were randomly allocated to receive either bimekizumab 160 mg or placebo every 4 weeks; all participants then received the study drug starting week 16. Patients reported spinal pain, peripheral pain, morning stiffness, and fatigue up to week 52.

Total and nocturnal spinal pain was evaluated using a 0‒10 numerical rating scale (NRS). Using individual Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) items (0‒10-point NRS), the investigators assessed peripheral arthritis pain, morning stiffness, and fatigue. They also reported the Functional Assessment of Chronic Illness Therapy Fatigue subscale score (FACIT-Fatigue).

At week 16, patients in the bimekizumab group demonstrated lower mean nocturnal spinal pain, total spinal pain, and BASDAI scores (nominal except for nocturnal spinal pain; all p≤0.001), as well as higher FACIT-Fatigue scores (nominal p<0.05), suggesting improved symptoms, than those in the placebo group. [J Rheum 2025;52:23-32]

These improvements were sustained through week 52 in continuous bimekizumab-treated patients and in those who switched to bimekizumab from week 16.

More patients treated with bimekizumab achieved increasingly stringent thresholds for low spinal and peripheral pain at week 16 compared with those on placebo. This trend persisted or improved at week 52. Similar results were observed for morning stiffness and fatigue.

In addition, more than half of the participants were deemed FACIT-Fatigue responders, defined as ≥8-point increase in score, at week 52.

“These findings, alongside previously published results, support the benefit of bimekizumab for managing clinical symptoms that are central to the patient experience and have significant impact on their daily lives,” the investigators said. [Ann Rheum Dis 2024;83:199-213; Ann Rheum Dis 2023;82:515-526]

Mediators

Pain in axSpA is influenced either directly or indirectly by inflammatory mediators. For instance, musculoskeletal inflammation has been shown to cause morning stiffness. [J Clin Rheumatol 2021;27:e446-455; Ann Rheum Dis 2009;68:784-788]

“The pathology of fatigue is less understood; however, inflammation is likely a contributing factor,” the investigators said. “Therefore, patients’ experience of pain, stiffness, and fatigue is important to consider when monitoring disease improvements.” [J Clin Rheumatol 2021;27:e446-455]

Although NSAIDs are effective in pain management, they are less effective at alleviating fatigue. In addition, poor sleep quality and depression, which are common in axSpA patients, may exacerbate fatigue. [Arthritis Res Ther 2023;25:136; Rheumatology 2003;42:1523-1528]

“Further research is required to investigate the relationships between the potential effect of bimekizumab on fatigue, sleep function, and depression,” the investigators said.