EHSF 2026: UCB presented long-term BE HEARD trial in patients with Hidradenitis Suppurativa

UCB has released long-term BE HEARD trial data showing that bimekizumab (Bimzelx) delivered deep and durable improvements in hidradenitis suppurativa over three years, with results showcased at the European Hidradenitis Suppurativa Foundation (EHSF) 2026 meeting.

The new analyses highlight bimekizumab’s capacity not only to clear inflammatory lesions but also to remodel disease severity categories and reduce structurally destructive draining tunnels over time.

Long-term HS results with bimekizumab at EHSF 2026

Among people with moderate to severe hidradenitis suppurativa who continued treatment, 40.1% achieved complete resolution of inflammatory HS lesions at three years, corresponding to IHS4-100 and reflecting the absence of inflammatory nodules, abscesses, and tunnels as captured by the International HS Severity Score System.

An additional proportion reached high levels of response, with 59.1% attaining at least a 90% improvement in IHS4 (IHS4-90) and 77.4% reaching at least a 75% improvement (IHS4-75), demonstrating that a majority of patients experienced profound disease control rather than partial benefit.

Among patients included in the severity analysis, the proportion classified as having severe hidradenitis suppurativa by IHS4 dropped from 87.4% (486 of 556 individuals) at baseline to 14.7% (54 of 367 individuals) at the three-year visit. Over the same period, the share of people categorized as having mild or inactive disease increased from 0.0% at study entry to 59.4% after three years of treatment.

Shifts in HS severity and draining tunnels over three years

Long-term treatment with bimekizumab led to a striking shift in overall HS severity distribution when classified using IHS4. At baseline, most participants in the extension population had severe disease, but by year three this severe category had markedly contracted and the proportion of patients with mild or inactive HS had grown substantially, with nearly six in ten moving into at least the mild range. This change reflects not just lesion counting but a broader reclassification of disease burden that is highly relevant to clinical practice and patient quality of life.

Draining tunnels, one of the most challenging and morbid features of hidradenitis suppurativa, also decreased meaningfully over time. In the BE HEARD extension, the mean number of draining tunnels fell from an average of close to four per patient at study entry to around one after three years, underscoring sustained structural improvement in chronic lesions that are often associated with scarring, pain, and recurrent infections. In parallel, a separate assessment documented continued gains in health-related quality-of-life measures, indicating that clinical responses translated into tangible everyday benefits for people living with HS.

BE HEARD program design and dosing strategy

The BE HEARD development program for bimekizumab in hidradenitis suppurativa consists of two pivotal Phase 3 trials, BE HEARD I and BE HEARD II, supported by the long-term open-label extension BE HEARD EXT. BE HEARD I and II were large, international, randomized, double-blind, placebo-controlled studies enrolling over 1,000 adults with moderate to severe HS, designed to rigorously evaluate efficacy and safety across multiple dosing regimens.

The primary endpoint in both core trials was achievement of HiSCR50 at Week 16, defined as at least a 50% reduction in abscess and inflammatory nodule count without worsening of abscesses or draining tunnels, ensuring that response captured both lesion reduction and stability of more invasive disease features.

Bimekizumab mechanism and role in HS

Bimekizumab is a humanized monoclonal antibody developed by UCB that selectively targets and neutralizes both interleukin 17A and interleukin 17F, two closely related cytokines that play a central role in inflammatory cascades across several immune-mediated diseases, including hidradenitis suppurativa. By inhibiting both IL-17A and IL-17F simultaneously, bimekizumab aims to achieve more complete suppression of type 17-driven inflammation than agents that block only one of these cytokines, which may help explain the depth and durability of lesion clearance observed in long-term studies.

In HS, where chronic nodules, abscesses, and draining tunnels reflect persistent immune activation and tissue damage, sustained dual IL-17A/IL-17F inhibition offers a biologically plausible strategy for achieving high thresholds of response such as IHS4-100 and meaningful structural improvement.

As more data from BE HEARD I, II, and EXT continue to emerge at key meetings like the European Hidradenitis Suppurativa Foundation conference, bimekizumab is becoming a central reference point in discussions about advanced systemic therapy for moderate to severe HS. For clinicians, researchers, and patients seeking detailed, long-term evidence on IL-17A/IL-17F inhibition, the BE HEARD program and EHSF presentations together define a major part of the evolving evidence base in hidradenitis suppurativa care.