Two months after UCB revealed the success of Bimzerx in a head-to-head trial with AbbVie’s Skyridi in patients with psoriatic arthritis (PsA), the Belgian drugmaker has released detailed results.
In a Phase 3B study of 553 patients, 49% of patients in the Bimzelx group experienced a reduction in disease activity at week 16, compared with 38% in the Skyrizi group. The results were deemed statistically significant, UCB said.
The primary endpoint of disease activity was measured by ACR50, a composite efficacy measure specified by the American College of Rheumatology. ACR50 indicates a 50% or greater improvement from baseline in the number of tender or swollen joints, in addition to a 50% improvement in three of five other disease markers.
According to UCB, Bimzerx outperformed Skyridge on several secondary metrics, but none of them achieved statistical significance. In one of these endpoints, Bimzelx achieved complete skin clearance in 53% of patients at week 16, compared to 47% of patients using Skyrizi. In minimal disease activity (MDA), another secondary metric that assesses overall disease control, Bimzerx outperformed Skyridi by 43% versus 40%.
In the secondary endpoint determining how many patients reached ACR50 after four weeks, the success rate for Bimzlex was 20% compared to 7% for Skyrizi.
According to UCB, this is the first time that an approved treatment has been demonstrated to be superior to IL-23 inhibitors such as Skyrizi in PsA. Bimzelx is the first therapy to selectively inhibit IL-17F and IL-17A pro-inflammatory proteins. The study included adults with active PsA who were new to biologic treatment or had an inadequate response to certain TNF inhibitors.
This is another victory for Bimzerx, which has already outperformed Novartis’ IL-17 Cosentyx, Johnson & Johnson’s IL-12 and IL-23 Stelara, and AbbVie’s TNF inhibitor Humira in previous psoriasis studies.
“Achieving high levels of clinical response is critical for patients with psoriatic arthritis. Achieving ACR50 level responses in clinical trials demonstrates joint improvements that correlate closely with clinically meaningful reductions in disease activity, inflammation control and consequent improvements in quality of life,” Ian McInnes, from the University of Glasgow’s School of Medicine and Veterinary Life Sciences, said in the release.
The results will be presented at the European Union of Rheumatology Association (EULAR) conference in London from June 3 to June 6.
Bimzelx’s sales increased significantly from €607 million ($716 million) in its first full year on the market to €2.2 billion ($2.6 billion) in 2025. Annual sales had already reached half of the company’s peak sales forecast of 4 billion euros ($4.4 billion). Bimzerx helped UCB’s 2025 revenue increase by 26% to 7.7 billion euros ($8.7 billion).
Bimzelx’s rapid uptake mirrors that of Skyrizi, which generated $355 million in sales in its first full year on the market, followed by $1.6 billion in 2020 and $2.9 billion the following year. Last year, Skyrizi generated $17.6 billion in revenue.
In addition to indications for psoriasis and PsA, Skyrizi is also approved for Crohn’s disease and ulcerative colitis. In addition to psoriasis and PsA, Bimzelx is also approved for active non-radiographic axial spondyloarthritis, active ankylosing spondylitis, and most forms of hidradenitis suppurativa (HS).

