A securities class action has been filed in the USDC – S.D.N.Y. against MoonLake Immunotherapeutics (MLTX) (“MoonLake” or the “Company”), on behalf of all persons and entities that purchased or acquired MoonLake common stock between March 10, 2024, and September 29, 2025, both dates inclusive (the “Class Period”).

MoonLake is a clinical-stage biotechnology company focused on developing therapies for inflammatory diseases driven by interleukin-17 (“IL-17”), particularly in dermatology and rheumatology. Its sole drug candidate, SLK, was developed primarily for the treatment of hidradenitis suppurativa (“HS”), as well as psoriatic arthritis, psoriasis, and axial spondyloarthritis.

Central to SLK’s commercial prospects was its ability to demonstrate efficacy in HS comparable or superior to BIMZELX, an FDA-approved monoclonal antibody for the same indication. While SLK’s Nanobody® structure differed from BIMZELX’s monoclonal antibody format by being significantly smaller, both drugs targeted the same inflammatory cytokines, IL17A and IL-17F.

The complaint alleges defendants made false and/or misleading statements, as well as failed to disclose material facts, regarding the distinction between the Nanobodies and monoclonal antibodies, including that:

(1) that SLK and BIMZELX share the same molecular targets (the inflammatory cytokines IL-17A and IL-17F);

(2) that SLK’s distinct Nanobody structure would not confer a superior clinical benefit over the traditional monoclonal structure of BIMZELX;

(3) SLK’s distinct Nanobody structure supposed increased tissue penetration would not translate to clinical efficacy; and

(4) based on the foregoing, Defendants lacked a reasonable basis for their positive statements regarding SLK’s purported superiority to monoclonal antibodies.

On September 28, 2025, MoonLake announced week-16 results from its Phase 3VELA program. The results showed that SLK failed to demonstrate competitive efficacy relativeto BIMZELX. Following the announcement, MoonLake’s stock price cratered, declining $55.75per share, or 89.9%, to close at $6.24 on September 29, 2025.

If you purchased MoonLake common stock during the Class Period and would like to receive more information or join the action, please enter your contact information below for a FREE consultation and click “Submit Your Information”.

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