Three-year data show lasting efficacy of bimekizumab across PsA domains

New analyses demonstrate that bimekizumab maintains high rates of clinical response across the skin, joints, and nails, irrespective of prior biologic exposure. Biologic-naïve patients with psoriatic arthritis (PsA), for example, achieved long-term response maintenance rates exceeding 80% in observed cases.

Sustained response following complete clinical resolution is an important treatment goal in PsA [1]. A post-hoc analysis of the phase 3 BE OPTIMAL (NCT03895203) and BE COMPLETE (NCT03896581) trials evaluated the durability of bimekizumab responses across skin, joint, and nail domains up to weeks 160 and 156, respectively. Completion rates at these timepoints exceeded 75% in both studies. The trials included biologic-naïve adults with PsA as well as patients with prior inadequate response to tumour necrosis factor (TNF) inhibitors.

Complete clinical resolution was defined as achieving Psoriasis Area and Severity Index (PASI) 100 or a swollen joint count (SJC) of 0 at week 16, or modified Nail Psoriasis Severity Index (mNAPSI) of 0 at weeks 24 or 28. Maintenance of ≥50% improvement per the American College of Rheumatology (ACR50) criteria, achieved at week 16, was also assessed. Outcomes were analysed using modified non-responder imputation (mNRI) and observed cases (OC).

In BE OPTIMAL, just under half of the patients with ≥3% body surface area involvement at baseline achieved PASI 100. In BE COMPLETE (patients with prior TNF inhibitors inadequate response), PASI 100 rates were 58.7% (mNRI) and 59.9% (OC). At 3 years, PASI 100 responses were sustained in 82.1% (OC) and 66.0% (mNRI) of biologic-naïve patients, and in 92.0% (OC) and 81.5% (mNRI) of pre-treated patients. Corresponding maintenance rates for mNAPSI=0 were 88.0% and 74.6% in BE OPTIMAL, and 91.0% and 80.7% in BE COMPLETE.

For joint outcomes, SJC=0 responses were maintained by 84.3% (OC) and 69.8% (mNRI) of week 16 responders in biologic-naïve patients. In BE COMPLETE, corresponding maintenance rates were 92.7% (OC) and 77.9% (mNRI). ACR50 responses were similarly durable, with approximately 90% (OC) and 80% (mNRI) of initial responders maintaining improvement across both studies.

Prof. Joseph Merola (UT Southwestern Medical Center, TX, USA) and colleagues concluded that these findings support bimekizumab as an effective long-term treatment option for patients with PsA, demonstrating sustained, high-level efficacy regardless of prior biologic exposure.

Merola JF, et al. Bimekizumab treatment resulted in long-term maintenance of complete clinical resolution across skin, joint, and nail domains in patients with active psoriatic arthritis: 3-year results from two phase 3 studies. Poster 73665. AAD 2026, 27–31 March, Denver, CO, USA.