MoonLake Immunotherapeutics launches Phase 3 trial for sonelokimab in psoriatic arthritis patients

On November 13, 2024, MoonLake Immunotherapeutics, a clinical-stage biotechnology company, announced the screening of the first patients at U.S. trial sites for its global Phase 3 clinical program, IZAR. This program evaluates sonelokimab, an investigational Nanobody® designed to treat inflammatory diseases in patients with active psoriatic arthritis (PsA).

PsA is a chronic inflammatory condition that affects peripheral joints, skin, entheses, nails, and axial joints. It presents significant challenges due to its multi-domain nature, highlighting a substantial unmet need for managing inflammation and pain. While the exact mechanisms of PsA are not fully understood, the activation of the IL-17 pathway is believed to play a crucial role. Sonelokimab, with its Nanobody® design, is created to target inflammation by inhibiting IL-17A/A, IL-17A/F, and IL-17F/F dimers. Its smaller size compared to traditional antibodies allows better penetration into inflamed tissues.

Following positive results from the Phase 2 ARGO trial, the Phase 3 IZAR program aims to enroll around 1,500 adult patients across two trials, IZAR-1 and IZAR-2. These global, randomized, double-blind, placebo-controlled trials will evaluate the efficacy and safety of sonelokimab over 52 weeks. IZAR-1 will focus on biologic-naïve patients and include radiographic progression evaluation, while IZAR-2 will involve patients with inadequate responses to tumor necrosis factor-α inhibitors (TNF-IR) and include risankizumab, a monoclonal antibody inhibiting IL-23, as an active reference. Both trials aim to read out primary (ACR 50) and key secondary endpoints by Week 16, with final results expected in the first half of 2026.

Alan Kivitz, MD, MACR, and IZAR investigator, expressed excitement about the Phase 3 IZAR program, highlighting the promising results from the Phase 2 ARGO trial, where up to 61% of patients achieved Minimal Disease Activity by Week 24. This trial aims to confirm the multi-domain efficacy of sonelokimab in treating PsA, ultimately improving patients' quality of life.

Philip J. Mease, MD, from the Providence Swedish Medical Center, commented on the innovative design of sonelokimab, which integrates Nanobody® technology with dual IL-17 inhibition. This novel approach aims to enhance treatment outcomes across multiple PsA domains compared to conventional antibodies. The Phase 3 IZAR program, therefore, represents a significant opportunity to advance PsA treatment.

Kristian Reich, Founder and Chief Scientific Officer at MoonLake, emphasized that the Phase 3 IZAR program marks a major milestone for the company. This initiative underscores MoonLake's commitment to advancing inflammation and immunology treatments in both dermatology and rheumatology, providing new options for patients with high unmet needs. The company is fully engaged in its late-stage clinical development plans and looks forward to reporting primary endpoint results in early 2026.

This Phase 3 program was initiated following successful end-of-Phase 2 interactions with the U.S. FDA and positive feedback from the European Medicines Agency. MoonLake's dedication to inflammatory disease research continues to drive its efforts in developing innovative treatments for conditions like PsA and hidradenitis suppurativa, aiming to revolutionize patient outcomes.