Patients who started bimekizumab less than 2.38 years after an hidradenitis suppurativa (HS) diagnosis achieved IHS4-100 — complete resolution of inflammatory lesions — at 3 years at a rate of 47.4%, versus 33.3% among those diagnosed 10.74 years or more before treatment, according to post hoc data from the phase 3 BE HEARD I and II trials and the BE HEARD EXT open-label extension.

UCB presented the findings at the 2026 European Academy of Dermatology and Venereology (EADV) Congress in Vienna, Austria, among nine HS-focused abstracts. Additional analyses covered draining tunnels by prior biologic exposure, total tunnel counts, quality of life, and long-term safety.

Bimekizumab (Bimzelx) selectively inhibits both interleukin 17F (IL-17F) and IL-17A. According to UCB, IL-17F is more abundant than IL-17A in HS serum and lesional skin, with the highest expression found in draining tunnels.

Does Disease Duration Shape Bimekizumab Response?

Investigators compared International HS Severity Score System (IHS4) responses between patients in the shortest disease duration quartile (less than 2.38 years since diagnosis; n = 97) and the longest (10.74 years or more; n = 81).

At 3 years, IHS4-90 responses followed the same pattern as IHS4-100: 62.9% in the shortest-duration group versus 53.1% in the longest. IHS4-75 rates were 79.4% versus 70.4%. IHS4-55 rates were comparable, at 89.7% and 91.4%, respectively.

Prior biologic use also appeared to influence draining tunnel outcomes. At 3 years, 67.3% of biologic-naive patients achieved complete draining tunnel resolution compared with 47.7% of biologic-experienced patients.

Mean draining tunnel count fell from 3.3 to 0.8 among biologic-naive patients and from 5.6 to 1.3 among biologic-experienced patients over the same period.

Did Bimekizumab Reduce Total Tunnel Burden?

A pooled 1-year analysis from BE HEARD I and II examined total tunnels, encompassing both draining and nondraining tracts. At baseline, 14.5% of 868 patients had no tunnels of any kind; among 613 patients completing the first year, that proportion rose to 30.7%.

Over the same period, the share of patients with no draining tunnels increased from 27.0% to 56.6%. Draining tunnels made up 37.3% of all tunnels at week 16 and 31.3% at 1 year.

Amit Garg, MD, of the Zucker School of Medicine at Hofstra/Northwell, characterized the total tunnel data as the first evidence of an HS therapy reducing overall tunnel burden, and suggested the data may indicate an effect on disease progression.

What Did 3-Year Quality of Life and Safety Data Show?

Mean Dermatology Life Quality Index (DLQI) scores declined from 11.0 at baseline to 4.5 at 3 years. In total, 38.1% of patients reached DLQI 0/1 and 71.7% reached DLQI 0 to 5. The share of patients with an HS Quality of Life (HiSQOL) total score of 14 or lower increased from 24.1% to 76.4%.

Mean symptom scores for skin pain, itch, odor, and drainage each dropped from moderate to severe levels at baseline to mild levels at 3 years.

The safety analysis included 995 subjects with 2118.6 patient-years of exposure. The exposure-adjusted incidence rate of any treatment-emergent adverse event was 243.3 per 100 patient-years, with HS, coronavirus infection, and oral candidiasis most common. UCB reported no new safety signals and no increase in risk with longer exposure.

Fungal infections occurred at a rate of 22.4 per 100 patient-years, including Candida infections at 13.5 per 100 patient-years.

All efficacy analyses were post hoc and used observed case data, and UCB noted the results should be interpreted with caution. The approved HS regimen is 320 mg every 2 weeks through week 16, followed by 320 mg every 4 weeks.

As BE HEARD EXT accumulates longer-term exposure data, the disease-duration findings are likely to sharpen the case for intervening with IL-17A/IL-17F inhibition before irreversible tunnel burden accumulates.