Journal of the European Academy of Dermatology and Venereology | February 14, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available
Abstract Background Hidradenitis suppurativa (HS) is a chronic, relapsing, debilitating skin disease characterized by deep‐seated nodules, abscesses and tunnels. Objectives To investigate the efficacy of bimekizumab using International Hidradenitis Suppurativa Severity Score System (IHS4) outcomes in patients with moderate to severe HS in the pooled BE HEARD I and II Phase 3 studies. Methods Patients received (initial/maintenance) bimekizumab 320 mg every 2 weeks (Q2W)/Q2W, bimekizumab Q2W/every 4 weeks (Q4W), bimekizumab Q4W/Q4W or placebo/bimekizumab Q2W. Change from baseline (CfB) in IHS4, IHS4 severity stages and the dichotomous IHS4‐55/75/90/100 (an improvement of at least 55%/75%/90%/100% in IHS4 from baseline) are reported to Week 48. Lesion count data by lesion type are reported to Week48. Results In total, 1014 patients were enrolled across BE HEARD I and II. At baseline, mean (standard deviation [SD]) IHS4 for bimekizumab‐treated patients ranged from 33.4 (25.4) for bimekizumab Q2W/Q2W to 36.0 (34.0) for bimekizumab Q2W/Q4W versus 30.6 (21.8) for placebo. At Week16, patients receiving bimekizumab demonstrated greater reductions in mean (SD) IHS4 from baseline, ranging from −17.2 (24.8) for bimekizumab Q4W/Q4W to −17.8 (21.1) for bimekizumab Q2W/Q2W versus −6.1 (16.3) for placebo. Proportions of patients with severe HS at baseline ranged from 83.7% (bimekizumab Q2W/Q2W) to 88.4% (bimekizumab Q2W/Q4W) and decreased by ~50% to Week48 across all treatment arms, ranging from 28.6% (placebo/bimekizumab Q2W) to 34.3% (bimekizumab Q2W/Q2W). Proportions of patients with IHS4 = 0 at Week48 ranged from 23.7% (bimekizumab Q2W/Q4W) to 26.7% (placebo/bimekizumab Q2W). At Week16, IHS4‐55, IHS4‐75, IHS4‐90 and IHS4‐100 thresholds were achieved by greater proportions of patients treated with bimekizumab versus placebo, while comparable improvements were seen across treatment arms from Week16 to Week48. At Week16, lesion counts were lower for patients treated with bimekizumab versus placebo, decreasing to comparable numbers across all groups at Week48. Conclusions Bimekizumab‐treated patients showed improvements across IHS4 outcome measures.
Standardization of Lesion Classification and Assessment by Investigators in Clinical Trials for Hidradenitis Suppurativa
Importance Accurate classification and reliability in assessment for lesions of hidradenitis suppurativa (HS) by investigators is critical to the determination of responder status and to overall data quality in clinical trials. Objective To establish consensus-based morphological definitions of HS lesions and guidance statements that standardize investigator lesion assessments for implementation in clinical trials. Evidence Review Health professionals (primarily dermatologists) with expertise in the measurement of HS disease activity as well as novice raters completed a preliminary questionnaire in which participants were asked to assess images of HS lesions and provide qualitative feedback on their decision making. Based on this feedback, detailed morphologic definitions for lesions and guidance statements that standardize lesion assessments were formulated and presented for consensus voting in 2 electronic Delphi surveys. A virtual group discussion after round 1 supported participants in round 2 voting. Findings Response rates were 84.7% (50 of 59), 86.0% (43 of 50), and 90.9% (40 of 44) in the preliminary, electronic Delphi round 1, and electronic Delphi round 2 surveys, respectively. Morphological definitions for 11 lesion types achieved the prespecified 70% consensus threshold, with 9 definitions reaching at least 90% agreement. After 2 electronic Delphi rounds, 16 of 18 guidance statements achieved the prespecified consensus threshold, with 13 statements receiving endorsement from more than 80% of participants. Two guidance statements related to assessment of tunneled plaques with multiple openings and assessment of scalp lesions failed to reach consensus. Conclusions and Relevance Common morphologic definitions and guidance that standardize assessment of HS lesions can be implemented in clinical trial protocols and investigator trainings with the goals of improving accuracy and reliability of investigator ratings.
Development and validation of
IHS4
‐55, an
IHS4
dichotomous outcome to assess treatment effect for hidradenitis suppurativa
Abstract Background Validated, inclusive and easy‐to‐use outcomes for hidradenitis suppurativa are essential both in the clinical trial setting and clinical practice. The continuous IHS4 is a validated tool that dynamically assesses nodules/abscesses/draining tunnels and classifies disease severity as mild/moderate/severe. However, dichotomous outcomes are often required for clinical trials reporting. Objective To develop and validate a dichotomous outcome based on IHS4 that can be used in clinical trial settings and day‐to‐day clinical practice. Methods De‐identified data from the PIONEER‐I and ‐II studies were accessed through Vivli. Potential IHS4 thresholds were analysed using baseline to Week 12 data from adalimumab‐ and placebo‐treated hidradenitis suppurativa patients in the PIONEER‐I trial. The final threshold was chosen based on its ability to discriminate between patients treated with adalimumab or placebo and its association with reduction in inflammatory lesions. The final threshold was validated using data from baseline to Week 12 from adalimumab‐ and placebo‐treated hidradenitis suppurativa patients in both the PIONEER‐II and the combined PIONEER‐I and ‐II studies. Results The best performing cut‐off for the IHS4 was a 55% reduction of the IHS4 score (IHS4‐55). Patients who achieved the IHS4‐55 had an odd's ratio of 2.00 [95%‐CI 1.26–3.18, p = 0.003], 2.79 (95%‐CI 1.76–4.43, p < 0.001) and 2.16 (95%‐CI 1.43–3.29, p < 0.001) for being treated with adalimumab rather than placebo in PIONEER‐I, PIONEER‐II and the combined dataset, respectively. Additionally, the achievement of the IHS4‐55 was associated with a significant reduction in inflammatory nodules, abscesses and draining tunnels in all analysed datasets. Conclusions IHS4‐55, a novel dichotomous IHS4 version, based on a 55% reduction of the total score was developed. The IHS4‐55 performs similarly to the HiSCR in discriminating between adalimumab‐ and placebo‐treated hidradenitis suppurativa patients and shows significant associations with reductions in lesion counts. Moreover, the IHS4‐55 addresses some of the HiSCR drawbacks by dynamically including draining tunnels in a validated manner. By allowing the analysis of hidradenitis suppurativa patients with an abscess and nodule count below 3 but many draining tunnels, this outcome measure will improve inclusivity in clinical trials.