Study: Anumigilimab Well Tolerated in HS and Palmoplantar Pustulosis

Anumigilimab was generally well tolerated in patients with hidradenitis suppurativa (HS) or palmoplantar pustulosis (PPP), while providing preliminary signals of clinical activity in both neutrophil-driven inflammatory skin diseases, results from a Phase 1b study suggest. 

The open-label, repeat-dose trial included 39 adults with moderate-to-severe disease (22 patients with HS and 17 with PPP). Participants received intravenous anumigilimab every 21 days for 15 weeks, followed by a 9-weeks of follow-up. The primary endpoint evaluated treatment-emergent adverse events (TEAEs), while secondary objectives included pharmacokinetics, immunogenicity, and pharmacodynamic effects.

Early Signal of Activity Supports Further Investigation

Overall, 84.6% of participants experienced at least one TEAE, with 41.0% experiencing treatment-related events. Fatigue and neutropenia were the most common treatment-related adverse events, each occurring in seven patients. Investigators reported that neutropenia resolved spontaneously and was not associated with an increased risk of infection. No deaths or serious treatment-related adverse events occurred. 

There was a dose-dependent relationship between anumigilimab exposure and reductions in absolute neutrophil counts. Even though efficacy was an exploratory endpoint, 57.9% of evaluable patients with HS achieved Hidradenitis Suppurativa Clinical Response (HiSCR50) at Week 15 and mean International HS Severity Score System (IHS4) scores declined by 40.3%. Patients with PPP saw a 40.4% reduction in Palmoplantar Pustulosis Area and Severity Index (ppPASI) scores. The investigators cautioned that these findings should be interpreted carefully because the study was small, lacked a placebo control, and was not powered to demonstrate efficacy.

"Anumigilimab was generally well tolerated in patients with HS or PPP, with no serious treatment-related safety concerns, and demonstrated dose-dependent pharmacology," the authors wrote. "While clinical responses in HS and PPP were observed, it should be noted that these observations were exploratory and signal-finding in nature. Importantly, the study was not powered to statistically confirm efficacy and lacked a placebo control, underscoring the need for future randomized, placebo-controlled trials to validate these preliminary signal-finding observations."

Source

Kern JS, et al. Journal of the European Acadacemy of Dermatology Venereology. 2026. Doi:10.1111/jdv.70594