Bimekizumab-Treated Patients with HS See IHS4 Outcome Improvement Over 1 Year

Treatment of hidradenitis suppurativa (HS) with bimekizumab led to significant improvements in patients’ International Hidradenitis Suppurativa Severity Score System (IHS4) outcomes during the BE HEARD I and II studies.1

These data on patients with HS and their IHS4 outcome improvements following bimekizumab therapy were authored by such investigators as Thrasyvoulos Tzellos, MD, PhD, a dermatologist in Norway at Nordland Hospital Trust. Tzellos and coauthors highlighted bimekizumab’s design as a humanized monoclonal immunoglobulin G1 (IgG1) antibody, selectively inhibiting interleukin (IL)-17F as well as IL-17A.

The team also described IHS4 as a validated clinician-rated tool.2 It includes draining tunnels to evaluate HS severity and can be implemented in routine clinical practice as well as clinical trials.

“While IHS4 assesses all key HS lesions, it places the greatest weight on draining tunnels, allowing the differences in efficacy of novel drug treatments in reducing HS severity to be observed,” the investigators wrote.1 “Here, the efficacy of bimekizumab in reducing HS severity, measured using IHS4 outcomes, is reported in patients with moderate to severe HS over 1 year in BE HEARD I and II.”

BE HEARD Pooled Data

In the phase 3 BE HEARD I and BE HEARD II studies, Tzellos et al used a randomized, double-blind, placebo-controlled, multi-center trial design. They conducted their research between March 2020 - September 2022, carrying out their analyses via pooled data from both studies. Each study consisted of a 16-week placebo-controlled induction phase, and this was followed by a 32-week maintenance period, for a total duration of 48 weeks.

In the initial treatment phase, Tzellos and colleagues assigned participants in a 2:2:2:1 ratio to 1 of 4 groups: bimekizumab 320 mg provided every 2 weeks (Q2W) through Week 48; bimekizumab 320 mg every 4 weeks (Q4W) through Week 48; bimekizumab 320 mg Q2W through Week 16 followed by 320 mg Q4W through Week 48; or placebo through Week 16 followed by bimekizumab 320 mg Q2W through Week 48. Their eligibility criteria for the study were published previously.

Bimekizumab Effect on IHS4 Scores

Across both studies, there were 1014 individuals included in the analysis. Baseline disease severity, assessed by the IHS4, indicated substantial disease burden among subjects. Mean (standard deviation [SD]) IHS4 scores for those placed in the bimekizumab arms ranged from 33.4 (25.4) in the Q2W/Q2W group to 36.0 (34.0) in the Q2W/Q4W group, compared with 30.6 (21.8) in the placebo group. By the 16-week mark, Tzellos and coauthors found those treated with bimekizumab showed greater reductions in IHS4 scores from baseline than those receiving placebo.1

Mean (SD) decreases ranged from −17.2 (24.8) in the Q4W/Q4W group to −17.8 (21.1) in the Q2W/Q2W cohort, whereas the placebo cohort were shown to have a diminished reduction of −6.1 (16.3). At the study’s point of entry, the proportion of those classified as having severe HS was high, ranging from 83.7% in the Q2W/Q2W arm to 88.4% in the Q2W/Q4W arm.1 By the 48-week mark, Tzellos et al noted a decline in this proportion by approximately half across treatment arms, falling to between 28.6% among individuals who transitioned from placebo to bimekizumab Q2W and 34.3% in the Q2W/Q2W cohort.

In addition, the percentage of individuals attaining an IHS4 score of 0 by Week 48 ranged from 23.7% in the Q2W/Q4W group to 26.7% among those who initially were given a placebo before switching to bimekizumab. Treatment via bimekizumab also resulted in increased response rates at multiple IHS4 improvement thresholds by Week 16.1 Greater proportions of subjects on active therapy achieved IHS4-55, IHS4-75, IHS4-90, and IHS4-100 compared with those assigned to placebo. From the 16 through 48-week marks, however, Tzellos and coauthors noted improvements became more similar across treatment groups as those originally assigned to placebo began receiving bimekizumab.

Consistent with these data, lesion counts were shown to be lower in the bimekizumab groups than in the placebo group at the 16-week mark, though by Week 48 lesion numbers were comparable among all study groups.

“The promising improvements seen with bimekizumab treatment highlight an opportunity to address the need for effective treatments against draining tunnels,” the team concluded.1

References

1. Tzellos T, Giamarellos-Bourboulis EJ, Zouboulis CC, et al. Bimekizumab efficacy using IHS4 outcomes in hidradenitis suppurativa: Results from BE HEARD I and II. J Eur Acad Dermatol Venereol. 2026 Feb 14. doi: 10.1111/jdv.70356. Epub ahead of print. PMID: 41689425.

2. Zouboulis CC, Tzellos T, European Hidradenitis Suppurativa Foundation Investigator Group, et al. Development and validation of the International Hidradenitis Suppurativa Severity Score System (IHS4), a novel dynamic scoring system to assess HS severity. Br J Dermatol. 2017 Nov;177(5):1401-1409. doi: 10.1111/bjd.15748. Epub 2017 Oct 30. PMID: 28636793.