Sophie Glatt

Objective Evaluate the efficacy and safety of dual neutralisation of interleukin (IL)-17A and IL-17F with bimekizumab, a monoclonal IgG1 antibody, in addition to certolizumab pegol (CZP) in patients with rheumatoid arthritis (RA) and inadequate response (IR) to certolizumab pegol. Methods During this phase 2a, double-blind, proof-of-concept (PoC) study (NCT02430909), patients with moderate-to-severe RA received open-label CZP 400 mg at Weeks 0, 2 and 4, and 200 mg at Week 6. Patients with IR at Week 8 (Disease Activity Score 28-joint count C-reactive protein (DAS28(CRP))>3.2) were randomised 2:1 to CZP (200 mg every 2 weeks (Q2W)) plus bimekizumab (240 mg loading dose then 120 mg Q2W) or CZP plus placebo. The primary efficacy and safety variables were change in DAS28(CRP) between Weeks 8 and 20 and incidence of treatment-emergent adverse events (TEAEs). Results Of 159 patients enrolled, 79 had IR at Week 8 and were randomised to CZP plus bimekizumab (n=52) or CZP plus placebo (n=27). At Week 20, there was a greater reduction in DAS28(CRP) in the CZP-IR plus bimekizumab group compared with the CZP-IR plus placebo group (99.4% posterior probability). The most frequent TEAEs were infections and infestations (CZP plus bimekizumab, 50.0% (26/52); CZP plus placebo, 22.2% (6/27)). Conclusions PoC was confirmed based on the rapid decrease in disease activity achieved with 12 weeks of CZP plus bimekizumab. No unexpected or new safety signals were identified when neutralising IL-17A and IL-17F in patients with RA concomitantly treated with CZP, but the rate of TEAEs was higher with dual inhibition.

Aims: To assess safety, pharmacokinetics (PK) and clinical efficacy of bimekizumab (formerly UCB4940), a novel humanized monoclonal antibody and dual inhibitor of interleukin (IL)‐17A and IL‐17F, in subjects with mild plaque psoriasis.Methods: Randomized, double‐blind, first‐in‐human study of bimekizumab in 39 subjects who received single‐dose intravenous bimekizumab (8–640 mg) or placebo (NCT02529956).Results: Bimekizumab demonstrated dose‐proportional linear PK and was tolerated across the dose range assessed. No subject discontinued due to treatment‐emergent adverse events and no severe adverse events were reported. Bimekizumab demonstrated fast onset of clinically‐meaningful effects on skin of patients with mild psoriasis as early as Week 2. Maximal improvements (100% or near 100% reductions from baseline) in all measures of disease activity were observed between Weeks 8–12 in subjects receiving 160–640 mg bimekizumab. The duration of effect at doses ≥160 mg was evident up to Weeks 12–20 after a single intravenous dose, dependent on endpoint.Conclusions: This is the first study to demonstrate the safety, tolerability and clinical efficacy of a dual IL‐17A and IL‐17F inhibitor, in subjects with mild psoriasis. Bimekizumab showed fast onset of clinically‐meaningful efficacy by Week 2, with a maximal or near‐maximal magnitude of response that was maintained up to study Weeks 12–20. These findings support the continued clinical development of bimekizumab for diseases mediated by both IL‐17A and IL‐17F, including psoriasis.