Bimekizumab Sustains PASI 0 in Nearly Half of Patients to Year 4

At the 2025 European Academy of Dermatology and Venereology (EADV) Congress in Paris, France, new long-term data on bimekizumab (Bimzelx; UCB), the dual IL-17A and IL-17F inhibitor, were presented across several phase 3 trials.¹ These results extend the evidence base for bimekizumab, already approved for psoriasis, psoriatic arthritis (PsA), axial spondyloarthritis, and hidradenitis suppurativa (HS) in the European Union/European Economic Area. In the US, bimekizumab has been approved for moderate to severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy, as well as for active PsA, active nonradiographic axial spondyloarthritis, active ankylosing spondylitis, and moderate to severe HS.² Key findings highlight sustained complete skin clearance up to 4 years, durable nail psoriasis resolution, and a low occurrence of PsA symptoms among high-risk patients.

Sustained Skin Clearance
Among patients achieving a Psoriasis Area and Severity Index (PASI) score of 0 (PASI 0) at week 16 who continued into the open-label extension (N = 503), researchers found 48.9% maintained complete skin clearance (PASI 0 at every visit) through year 4. An additional 72.0% achieved sustained remission, defined as PASI 0 at all visits except up to 4 visits with a PASI score of greater than 0 to less than or equal to 2. In parallel, 69.4% maintained body surface area (BSA) less than or equal to 1% throughout the period, and 81.7% maintained high disease control (BSA ≤ 1% at every visit except up to 4 visits with BSA > 1% to ≤ 3%).

These data are clinically meaningful, with the company noting that sustained PASI 0 beyond 1 or 2 years is rarely reported in large cohorts. For practicing dermatologists, the durability of skin clearance directly addresses concerns about long-term disease control and treatment fatigue.

Nail Psoriasis and Risk of Progression to PsA
Nail psoriasis is not only a difficult-to-treat manifestation but also an established risk factor for PsA development. In this analysis, 81.8% of patients achieved complete clearance of the nail matrix (mNAPSI 0), and 82.7% cleared the nail bed by year 3. These findings suggest that bimekizumab may reduce progression risk by targeting early nail-driven inflammatory pathways.

PsA Risk Reduction
A separate data set assessed patients with psoriasis and at least 4 PsA risk factors at baseline. At 3 years, 98.1% maintained a PsA Screening and Evaluation score of less than 47, indicating no PsA symptoms. Over 4 years, only 2.6% (0.9/100 person-years) developed PsA-related treatment-emergent adverse events. Although confirmatory trials are needed, researchers stated that this low incidence raises the possibility that early intervention with bimekizumab could alter disease trajectory in high-risk patients with psoriasis.

Mechanism and Differentiation
Bimekizumab remains the only approved therapy that selectively inhibits both IL-17A and IL-17F. This dual blockade may underlie its depth of response and durability compared with single-pathway inhibitors. Clinicians should also note that oral candidiasis and other mucocutaneous infections remain the most common adverse events. Inflammatory bowel disease (IBD) exacerbations have been reported, and caution is advised in patients with known IBD.

Clinical Implications
For clinicians, the ability to sustain remission and prevent progression to PsA could mark a shift in treatment strategy. Instead of managing flares episodically, clinicians may increasingly adopt a “treat-to-target” approach with durable complete clearance as a realistic end point. Nail disease resolution further strengthens the case for early aggressive therapy in patients with risk factors for joint involvement.

Conclusion
Data presented at the EADV Congress demonstrate that bimekizumab delivers high, durable efficacy in moderate to severe plaque psoriasis, with nearly half of week-16 PASI 0 responders maintaining complete clearance over 4 years. Improvements in nail psoriasis and low PsA incidence among high-risk patients suggest additional benefits beyond skin control. These results support the role of bimekizumab as a long-term disease-modifying therapy for psoriasis, though vigilance regarding infections and IBD risk remains critical.

References

1. Bimzelx (bimekizumab) data in moderate-to-severe plaque psoriasis at EADV showed four-year sustained remission, and potential to reduce psoriatic arthritis progression risk. Press release. UCB. September 17, 2025. Accessed September 17, 2025. https://www.ucb.com/newsroom/press-releases/article/bimzelxrv-bimekizumab-data-in-moderate-to-severe-plaque-psoriasis-at-eadv-showed-four-year-sustained-remission-and-potential-to-reduce-psoriatic-arthritis-progression-risk
2. Bimzelx (bimekizumab-bkzx). Accessed September 17, 2025. https://www.bimzelx.com/