Dual Inhibition of IL-17 With Bimekizumab Improves Efficacy Outcomes in Axial Spondyloarthritis

Dual inhibition of interleukin (IL)-17A and IL-17F with bimekizumab significantly improves efficacy outcomes in nonradiographic and radiographic axial spondyloarthritis (nr-axSpA and r-axSpA, respectively), according to study results published in Annals of the Rheumatic Diseases.

Researchers reported findings from 2 parallel, placebo-controlled, double-blind, phase 3 trials evaluating the efficacy and safety of bimekizumab with dual inhibition with IL-17A and IL-17F in nr-axSpA (BE MOBILE 1; ClinicalTrials.gov Identifier: NCT03928704) and r-axSpA (BE MOBILE 2; ClinicalTrials.gov Identifier: NCT03928743).

Adults with active axSpA and spinal pain with a score of 4 or more on the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) were eligible to participate in the study.

Both nr- and r-axSpA eligibility were based on classification criteria from the Assessment of the Spondyloarthritis International Society (ASAS). Two independent readers inspected plain radiographs to screen for the absence (BE MOBILE 1) or presence (BE MOBILE 2) of definite sacroiliitis. Each trial included a placebo-controlled double-blind treatment period of 16 weeks, followed by a 36-week active-treatment maintenance period.

Patients were randomly assigned 1:1 (BE MOBILE 1) or 2:1 (BE MOBILE 2) to receive 160 mg of bimekizumab or placebo every 4 weeks up to week 16, followed by 160 mg of bimekizumab every 4 weeks through week 52.

The primary endpoint was at least 40% improvement in the ASAS response at week 16 (ASAS40). Secondary endpoints included efficacy measures at week 16. Treatment-emergent adverse events (TEAEs) up to week 24 were also reported.

A total of 254 patients with nr-axSpA and 332 with r-axSpA were included in the analysis.

In both trials, the primary endpoint was met at week 16 (nr-axSpA, 47.7% bimekizumab vs 21.4% placebo; r-axSpA, 44.8% vs 22.5%; P <.001). Tumor necrosis factor inhibitor (TNFi)-naive and -inadequate responder patients had similar ASAS40 responses. In addition, all ranked secondary endpoints were met at week 16 in both trials.

Researchers noted improvements in Ankylosing Spondylitis Disease Activity Scores (ASDAS) and inflammation measures, including C reactive protein and magnetic resonance imaging (MRI) scans of the sacroiliac joints and spine.

Nasopharyngitis, upper respiratory tract infection, pharyngitis, diarrhea, headache, and oral candidiasis were the most frequently occurring TEAEs with bimekizumab (>3%). More fungal infections (localized) occurred with bimekizumab use than with placebo. Low numbers of uveitis and adjudicated inflammatory bowel disease incidents were reported. Overall, no major adverse cardiovascular events or active tuberculosis were reported.

Study limitations included the short testing period (24 weeks) and the fact that patients were not blinded to active treatment after week 16.

However, according to the study authors, “Bimekizumab may [o]ffer patients with axSpA an effective treatment option with a novel mode of action.” They concluded that additional studies were necessary to make head-to-head comparisons between bimekizumab and other IL-17 inhibitors.

Disclosure: This research was supported by UCB Pharma. Please see the original reference for a full list of authors’ disclosures.