Safety and pharmacokinetics of anumigilimab for hidradenitis suppurativa or palmoplantar pustulosis: A phase 1b study.

In 30 seconds

This phase 1b, open-label, repeat-dose study assessed anumigilimab safety, pharmacology and exploratory clinical responses in 39 patients with hidradenitis suppurativa (HS) or palmoplantar pustulosis (PPP). Treatment-emergent adverse events occurred in 33 patients (84.6%); 16 (41.0%) had events considered related to anumigilimab, most commonly fatigue and neutropenia. No deaths or serious treatment-related adverse events occurred. Drug exposure and neutrophil reduction were dose dependent. At Week 15, 57.9% of HS patients with available data (11/19) achieved ≥50% HS Clinical Response; clinical findings were exploratory and the study was not powered to confirm efficacy.

Key findings

• Thirty-three of 39 patients (84.6%) experienced treatment-emergent adverse events; 16 (41.0%) had 70 events considered related to anumigilimab.
• Fatigue and neutropenia were the most common related events (both n = 7); they resolved spontaneously, with no observed association between neutropenia and infections.
• No deaths or serious treatment-related adverse events occurred, and antidrug antibodies were negligible.
• At Week 15, 11/19 HS patients with data (57.9%) achieved ≥50% HS Clinical Response; IHS4 decreased by 40.3%, and PPP ppPASI decreased by 40.4%.

Why it matters

The study provides early safety and pharmacology data for blocking G-CSFR in two neutrophil-driven skin diseases. The observed neutrophil reduction was dose dependent, while clinical improvements were exploratory and not dose dependent. These findings help characterize potential treatment effects and safety signals, but do not establish clinical efficacy.

What to keep in mind

The open-label study had no placebo control and was not powered to confirm efficacy. Its small sample and imbalanced baseline characteristics limit interpretation of the exploratory clinical responses.