Core Viewpoint - A class action lawsuit has been filed against MoonLake Immunotherapeutics, alleging violations of federal securities laws due to false and misleading statements regarding the company's business and prospects [1][6]. Company Overview - MoonLake Immunotherapeutics is a Swiss clinical-stage biotechnology company focused on inflammatory diseases driven by interleukin-17 (IL-17), particularly in dermatology and rheumatology [4]. - The company's sole drug candidate, sonelokimab (SLK), is primarily developed for hidradenitis suppurativa (HS) and also targets psoriatic arthritis, psoriasis, and axial spondyloarthritis [4]. Clinical Development - MoonLake began its Phase 2b MIRA trial of sonelokimab in May 2022, reporting positive top-line results in June 2023, achieving its primary HiSCR75 endpoint [5]. - Follow-up data in October 2023 indicated further improvement with continued treatment, and both the FDA and EMA endorsed the proposed Phase 3 program, which began patient screening in May 2024 [5]. Allegations and Stock Impact - The lawsuit claims that throughout the class period, the defendants made false statements regarding the efficacy of SLK compared to traditional monoclonal antibodies, including claims about molecular targets and clinical benefits [6]. - On September 28, 2025, MoonLake announced that SLK failed to demonstrate competitive efficacy relative to the traditional monoclonal structure BIMZELX, leading to a significant stock price drop of $55.75 per share, or 89.9%, closing at $6.24 on September 29, 2025 [7].