UCB: New Data at EULAR 2026 Reinforces Cimzia's Profile
UCB presented new mechanistic data on Cimzia (certolizumab pegol) at EULAR 2026 on Friday, showing that its lack of an Fc domain allows it to maintain consistent efficacy in patients with rheumatoid arthritis, regardless of rheumatoid factor levels.
In Vitro Data Explains Rheumatoid Factor-Independent Efficacy
The data presented at EULAR 2026 demonstrates that the rheumatoid factor (RF) binds to biologics containing an Fc domain, forming immune complexes that trigger the release of pro-inflammatory cytokines. In contrast, certolizumab pegol, which lacks an Fc domain, is not bound by the rheumatoid factor and does not generate immune complexes or induce cytokine production. These observations provide an explanatory mechanism for the previously reported clinical effects of certolizumab pegol, which remains effective regardless of the level of rheumatoid factor.
Regulatory Update Reflecting Structural Differentiation
The Summary of Product Characteristics (SmPC) for Cimzia in the European Union has been updated in section 5.1 to better describe its mechanism devoid of an Fc domain, reinforcing the mechanistic differences compared to biologics containing one. This update is also reflected in the product information in the United Kingdom, maintained by the Medicines and Healthcare products Regulatory Agency (MHRA). Together, these regulatory elements and emerging in vitro data support the differentiation of certolizumab pegol in patients with varying rheumatoid factor profiles.
High Rheumatoid Factor and Therapeutic Implications
High rheumatoid factor remains common in clinical practice and has been associated with lower exposure and reduced responses to TNF inhibitors containing an Fc domain (e.g., adalimumab). It is estimated that about one in four patients treated with biologic therapies presents high levels of rheumatoid factor, historically associated with a poorer prognosis and reduced efficacy of certain biologics containing one. James Galloway, professor of rheumatology at King's College London and honorary consultant at King's College Hospital in London, emphasized that the rheumatoid factor goes beyond its role as a mere diagnostic marker and can significantly influence patient responses to therapy.
