As reported on BioPharmaDive, UCB has reported positive results from a head-to-head clinical trial showing that its anti-inflammatory biologic Bimzelx was more effective than AbbVie’s Skyrizi in patients with active psoriatic arthritis. While the findings reinforce the therapeutic potential of IL‑17 inhibition in joint disease, financial analysts suggest the outcome is unlikely to significantly shift market dynamics in the near term.
The study, known as BE BOLD, compared the two biologics in 553 adults with psoriatic arthritis who were randomly assigned to receive either treatment. After 16 weeks, patients treated with Bimzelx achieved superior symptom improvement based on the trial’s primary endpoint, ACR50. This measure reflects a 50% reduction in tender and swollen joint counts, along with comparable improvements in other clinical indicators of disease activity.
Bimzelx targets interleukin‑17, a cytokine involved in inflammatory pathways, and is currently the only approved therapy designed to inhibit both the IL‑17A and IL‑17F subtypes. By contrast, Skyrizi works upstream by blocking interleukin‑23, another immune signaling protein implicated in inflammatory diseases. According to UCB, the results make Bimzelx the first biologic to demonstrate superiority over an IL‑23 inhibitor specifically in psoriatic arthritis.
Interest in IL‑17 inhibition has been building for years, driven by its established role in inflammatory and autoimmune conditions. Earlier entrants in this class, such as Novartis’ Cosentyx and Eli Lilly’s Taltz, have become major revenue generators. Approved by the U.S. Food and Drug Administration in 2023, Bimzelx has followed a similar growth trajectory, with annual sales rising sharply to approximately €2.2 billion (about $2.5 billion) last year. Even so, IL‑17 blockers continue to face stiff competition from IL‑23 agents, including Skyrizi as well as Johnson & Johnson’s Tremfya and Stelara.
BE BOLD represents the fourth study in which Bimzelx has shown an advantage over competing therapies across psoriatic disease, and the first to focus specifically on psoriatic arthritis. UCB indicated that comprehensive trial data will be shared at a future international medical meeting.
Despite the clinical win, equity analysts expressed caution about the broader implications. Jefferies analyst Michael Leuchten noted that the outcome was largely anticipated, as IL‑17 inhibition is thought to have particular benefits in joint‑dominant disease. He also pointed out that the trial design and early timepoint favored IL‑17 biology, limiting the likelihood of an immediate impact on prescribing behavior or sales volumes.
RBC Capital Markets analyst Trung Huynh offered a similar assessment, suggesting the announcement could prompt short-term stock market movement but is unlikely to undermine AbbVie’s established immunology portfolio. Overall, the results strengthen Bimzelx’s scientific profile, even as the commercial battle in psoriatic disease remains highly competitive.
