Glancy Prongay & Murray LLP, a Leading Securities Fraud Law Firm, Encourages MoonLake Immunotherapeutics (MLTX) Shareholders to Inquire About Securities Fraud Class Action

LOS ANGELES--(BUSINESS WIRE)--Glancy Prongay & Murray LLP, a leading national shareholder rights law firm, announces that a securities fraud class action lawsuit has been filed on behalf of investors who purchased or otherwise acquired MoonLake Immunotherapeutics (“MoonLake” or the “Company”) (NASDAQ: MLTX) common stock between March 10, 2024 and September 29, 2025, inclusive (the “Class Period”). MoonLake investors have until December 15, 2025 to file a lead plaintiff motion.

IF YOU SUFFERED A LOSS ON YOUR MOONLAKE IMMUNOTHERAPEUTICS (MLTX) INVESTMENTS, CLICK HERE TO INQUIRE ABOUT POTENTIALLY PURSUING CLAIMS TO RECOVER YOUR LOSS UNDER THE FEDERAL SECURITIES LAWS

What Happened?

On September 28, 2025, MoonLake Immunotherapeutics announced disappointing Phase 3 results for its only drug candidate, sonelokimab (“SLK”), revealing that SLK failed to match the efficacy of its competitor, Union Chimique Belge’s bimekizumab-bkz (“BIMZELX”). The Company had repeatedly promoted SLK’s nanobody structure as superior to other monoclonal antibodies—while allegedly failing to disclose it targeted the same molecules and lacked proven advantages.

Following the news, MoonLake’s stock fell $55.74, or 89.9%, to close at $6.24 per share on September 29, 2025, and thereby harming investors.

What Is the Lawsuit About?

The complaint filed in this class action alleges that throughout the Class Period, Defendants made materially false and/or misleading statements, as well as failed to disclose material adverse facts about the Company’s business, operations, and prospects. Specifically, Defendants failed to disclose to investors 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) as a result, Defendants’ positive statements about the Company’s business, operations, and prospects were materially misleading and/or lacked a reasonable basis at all relevant times.

If you purchased or otherwise acquired MoonLake common stock during the Class Period, you may move the Court no later than December 15, 2025 to request appointment as lead plaintiff in this putative class action lawsuit.

Contact Us to Participate or Learn More:

If you wish to learn more about this action, or if you have any questions concerning this announcement or your rights or interests with respect to these matters, please contact us:

Charles Linehan, Esq.
Glancy Prongay & Murray LLP
1925 Century Park East, Suite 2100
Los Angeles California 90067
Email: [e-mail]
Telephone: [phone]
Toll-Free: 888-773-9224
Visit our website at www.glancylaw.com.
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If you inquire by email, please include your mailing address, telephone number and number of shares purchased.

To be a member of the Class you need not take any action at this time; you may retain counsel of your choice or take no action and remain an absent member of the Class.

This press release may be considered Attorney Advertising in some jurisdictions under the applicable law and ethical rules.