ACELYRIN, INC. has announced positive long-term data from its Phase 2b clinical trial of izokibep in hidradenitis suppurativa (HS), demonstrating sustained clinical responses and deepening benefits with longer treatment duration. The 32-week data indicated no new safety concerns and showed continued improvements in clinical outcomes over time.
The open-label extension study revealed that patients who switched from placebo to izokibep at week 16 achieved similar response rates in Hidradenitis Suppurativa Clinical Response (HiSCR), reduction in draining tunnels, and alleviation of skin pain, comparable to those who started izokibep at baseline. Notably, a significant proportion of patients achieved high-order HiSCR responses, with approximately one-third reaching HiSCR100, indicating complete resolution of abscesses and nodules, by week 16 and sustained through week 32.
Consistent and Robust HiSCR Responses
"The magnitude and depth of responses for signs and symptoms of Hidradenitis Suppurativa in this long-term study are consistent with izokibep’s mechanism of action," said Kim Papp, MD, PhD, President and Director of Research, Probity Medical Research, Inc. He also noted the appreciable clinical responses observed in the placebo cross-over cohort, highlighting the potential for izokibep to deliver differentiated clinical benefits for patients.
Impact on Quality of Life
The study also highlighted marked reductions in draining tunnels and skin pain, contributing to clinically meaningful improvements in patients' quality of life, as measured by the Dermatology Life Quality Index (DLQI). These improvements underscore the potential of izokibep to address the debilitating effects of HS, which include pain, malodor, and disfigurement.
Safety and Tolerability
Izokibep demonstrated a favorable safety profile consistent with previous experience and the IL-17A class of drugs. There was no evidence of increased risk of infection, including fungal infections, or suicidal ideation and behavior, which can be concerns in this patient population.
Ongoing and Future Studies
ACELYRIN expects topline data from an ongoing Phase 3 trial in HS by the end of 2024. Additionally, a confirmatory Phase 3 trial involving approximately 400 patients is planned to meet regulatory guidance on safety database size, given that moderate-to-severe HS is no longer considered an orphan disease by the FDA.
About Hidradenitis Suppurativa
Hidradenitis Suppurativa (HS) is a chronic inflammatory skin disease characterized by scarring, abscesses, malodor, and pain, predominantly occurring in areas with high concentrations of sweat glands. It significantly impacts patients' quality of life, leading to increased disability and missed workdays. In 2019, an estimated 317,000 HS patients were in the U.S., with 50-60% classified as having moderate-to-severe HS.
About Izokibep
Izokibep is a small protein therapeutic designed to inhibit IL-17A with high potency. Its unique characteristics, including tight binding affinity, potential for robust tissue penetration due to its small molecular size, and an albumin-binding domain that extends half-life, may offer clinically meaningful and differentiated benefits for patients. Izokibep is currently being evaluated in multiple late-stage trials for HS, psoriatic arthritis (PsA), and uveitis, with plans to initiate a Phase 3 program in axial spondyloarthritis (AxSpA).
