EADV 2025: Hidradenitis suppurativa highlights

EADV 2025: Emerging agents for HS

At the European Academy of Dermatology and Venereology (EADV) Congress 2025, experts presented new data highlighting advances in the treatment of hidradenitis suppurativa (HS) aimed at addressing the diverse unmet needs that define HS. Updates included:

• Extension phase data from the STOP-HS trials of povorcitinib
• Phase 3 data for izokibep, a novel interleukin (IL)-17A inhibitor
• The latest from the open-label BE HEARD extension

Povorcitinib: 24-week data in moderate to severe HS

Martina Porter (Harvard Medical School, Boston, Massachusetts, USA) presented interim results from the extension phase of the STOP-HS1 and STOP-HS2 phase 3 trials evaluating povorcitinib, a selective oral Janus kinase 1 (JAK1) inhibitor, for moderate to severe HS.

Povorcitinib treatment drove continued gains through week 24 across multiple endpoints

In total, 608 and 619 patients with an abscess nodule (AN) count of ≥5 in ≥2 anatomic areas and an HS diagnosis for ≥3 months were randomized in STOP-HS1 and STOP-HS2, respectively. Participants had prior treatment with systemic therapy, and concomitant antibiotic use for HS was not allowed for the trial duration.

The previously reported week 12 findings showed a ≥50% decrease in baseline nodule and abscess count with no increase (HiSCR50) in 40–42% of patients on povorcitinib (45 mg or 75 mg/day) versus 29–30% of those taking placebo.

After this point, patients taking placebo switched to povorcitinib and entered the 42-week extension phase. By week 24, 50–64% of patients across treatment arms achieved HiSCR50. Rates of HiSCR75, 90, and 100 reached 31–40%, 14–28%, and 9–21%, respectively.

The proportion of patients with complete resolution of draining tunnels also rose, from 35–42% at week 12 to 39–51% at week 24, and the proportion with mild or no skin pain rose from approximately 35% to 70%.

Treatment-related adverse events (AEs) occurred in 30–48% of povorcitinib-treated patients and 16–26% of those who switched from placebo. Serious AEs affected 3–5% and 0–4% of patients, respectively. AEs of special interest were noted in 4–7% of povorcitinib-treated patients, with hematologic abnormalities reported in <1%.

Porter concluded by describing povorcitinib as a promising oral option for addressing moderate to severe HS, stressing the “deep clinical responses” achieved over 24 weeks.

Izokibep: IL-17A inhibition for HS

Kim Papp (University of Toronto, Ontario, Canada) presented 16-week results from a phase 3 trial of izokibep, a small-protein therapeutic designed to selectively inhibit IL-17A with high potency.

Izokibep demonstrated greater HiSCR response and pain reduction when compared with placebo, with over one in five patients achieving HiSCR100 by week 16

In the randomized, double-blind study, 258 patients with moderate to severe HS were assigned to either weekly subcutaneous izokibep 160 mg or placebo. At week 16, 50% of izokibep-treated patients (n=103) achieved HiSCR50 versus 32% of the placebo group (n=109). The corresponding rates were 37% versus 20% for HiSCR75, 24% versus 12% for HiSCR90, and 21% versus 9% for HiSCR100.

Dermatology Life Quality Index (DLQI) improvements were larger with izokibep than placebo (–4.4 vs –2.9). Of individuals with baseline pain scores ≥4, 38% taking izokibep achieved a ≥3-point reduction in pain versus 17% of those given placebo. In addition, 46% of people treated with izokibep with a baseline Hurley stage  2 achieved an AN count of ≤2 at week 16, compared with 29% of those on placebo.

Most treatment-emergent AEs (TEAEs) were mild or moderate, with the most common in the active-treatment group being injection-site reactions (67%) followed by headache (11%), nasopharyngitis (9%), diarrhea (5%), fatigue (5%), and upper respiratory tract infection (5%).

Serious TEAEs were rare, occurring in 1% of those treated with izokibep versus 4% of those taking placebo. There were no reported cases of Candida infection, inflammatory bowel disease, or suicidal ideation.

Papp concluded that izokibep may offer a rapid option for HS that meaningfully improves symptoms while having a manageable safety profile.

Bimekizumab: Efficacy and quality of life over 3 years

John Ingram (Cardiff University, UK) presented long-term data from the BE HEARD  I and II trials and their open-label extension BE HEARD EXT, evaluating bimekizumab, a monoclonal antibody targeting IL-17A and IL-17F, in patients with moderate to severe HS.

Patients continued to experience clinical responses and improvements in dermatology-related quality of life through 148 weeks of treatment

Of the 1,014 eligible individuals enrolled, 556 who were randomized to bimekizumab at baseline completed 48 weeks and entered the extension study; 367 went on to complete 148 weeks.

At week 48, HiSCR50/75/90/100 response rates were 79.9%, 64.0%, 42.3%, and 30.2%, respectively, increasing to a corresponding 90.2%, 81.2%, 64.3%, and 50.1% at 148 weeks. Mean reduction in draining tunnel count improved from –2.4 at week 48 to –3.1 at week 148.

At 48 weeks, 27.4% of participants achieved DLQI scores of ≤1, rising to 38.1% at 148 weeks.

Serious TEAEs occurred at a rate of 7.2 per 100  participant–years (PY) across the full 3 years of exposure, and discontinuations due to TEAEs at 6.0 per 100 PY. The most common TEAEs were HS flares (20.7/100  PY), COVID-19 infection (15.3/100 PY), and oral candidiasis (10.4/100 PY). Serious infections occurred in 40 participants (2.0/100 PY).

Ingram concluded by reiterating that clinical improvements observed at year 1 in the BE HEARD I and II trials were maintained or further improved through 3 years of treatment. Bimekizumab was well-tolerated throughout, and there were no new safety signals.

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