Désirée van der Heijde, MD, PhD: Safety, Efficacy of Bimekizumab in Ankylosing Spondyloarthritis

Rheumatology Network sat down with Désirée van der Heijde, MD, PhD, to discuss her recent European Alliance of Associations for Rheumatology (EULAR) 2022 conference presentation, “Bimekizumab in Patients with Active Ankylosing Spondylitis: 24-Week Efficacy & Safety from BE MOBILE 2, a Phase 3, Multicentre, Randomised, Placebo-Controlled Study.” Van der Heijde is Professor of Rheumatology at Leiden University Medical Center (LUMC), in the Netherlands.

Bimekizumab (BKZ), a monoclonal IgG1 antibody, selectively inhibits interleukin-17F (IL-17F) as well as IL-17A. Previously, results from a phase 2b study indicated that patients receiving the drug reported both rapid and long-term efficacy and was generally well tolerated in patients with active ankylosing spondylitis (AS). Van der Heijde and her team further assessed the safety and efficacy of BKZ in the phase 3 study, BE MOBILE 2 (NCT03928743). Initially, a total of 332 adult patients with active AS (mean age 40.4 years, 72.3% male, disease duration 13.5 years) were randomized to receive BKZ 160mg every 4 weeks (n = 221) or placebo (n =111).

Rheumatology Network: Why did your team decide to study bimekizumab in patients with active ankylosing spondylitis?

Désirée van der Heijde, MD, PhD: It is considered that inhibiting both those IL-17 factors is more efficacious than only inhibiting IL-17A. There was another program designed studying the efficacy in both radiographic axial spondyloarthritis (axSpA) and non-radiographic axial spondyloarthritis (nr-axSpA).

RN: Can you tell me a bit about the study design that your team ultimately utilized?

vdH: We performed a phase 3, randomized, controlled, double-blind trial comparing bimekizumab with placebo. The primary endpoint was after week 16, and thereafter, all disabled patients switched to active treatment and were followed until week 52 as well as a further long-term extension.

RN: What were your primary and secondary endpoints?

vdH: The primary endpoint was the Assessment in SpondyloArthritis international Society 40% (ASAS40) after 16 weeks. There were many secondary endpoints, all ranked, and they included different signs and symptoms, function, quality of life, and different things that are important for patients with axSpA.

RN: And were the results of your study?

vdH: There was a significant inhibition of bimekizumab in comparison to placebo for the ASAS40 (44.8% vs 22.5%, respectively) and for all secondary ranks. It should also be noted that there was good effect on MRI inflammation in both the spine and sacroiliac joints (SIJs), significant reductions in high-sensitive C-reactive protein (hs-CRP), and objective signs of inflammation were inhibited.

Additionally, responses were rapid among patients initially receiving placebo who switched to BKZ at week 16, which increased through week 24. At week 24, ≥50% achieved Ankylosing Spondylitis Disease Activity Score (ASDAS) <2.1. No major adverse cardiac events (MACE) or deaths occurred in either group. The most frequent adverse events included nasopharyngitis, headache, and oral candidiasis.

RN: What is the clinical significance of these results for both patients and rheumatologists?

vdH: This shows that indeed, inhibition of IL-17A and IL-17F is efficacious. If the full program is ready for submission, then it's possible that there will be a new treatment available for patients and rheumatologists. It’s advantageous for both.

RN: What are the next steps for your team?

vdH: There will be a further follow-up of the patients that are in the trial to get more long-term information on both safety and efficacy.