Introduction to the MoonLake Class Action Lawsuit
- Who is Affected? Purchasers or acquirers of MoonLake Immunotherapeutics (NASDAQ: MLTX) common stock between March 10, 2024 and September 29, 2025.
- The Problem: The MoonLake class action lawsuit alleges the defendant made false and misleading statements driving the stock price artificially up until the truth emerged and the stock plummeted and shareholders who purchased during the relevant time period and suffered a loss are entitle to damages
- Your Action: You may be eligible to recover your losses
- Deadline to Lead: The deadline to apply to be Lead Plaintiff is December 15, 2025
Read to learn the five things every investors must know about the MoonLake class action lawsuit.
1. The Allegations in the MoonLake Class Action Lawsuit
Overview
MoonLake is a clinical stage biotechnology company that focuses on developing therapies for inflammatory skin and joint diseases.
- According to the complaint, MoonLake’s sole drug candidate is sonelokimab (“SLK”), which was developed primarily for the treatment of hidradenitis suppurativa (“HS”).
- Central to SLK’s commercial prospects was its ability to demonstrate efficacy in HS comparable or superior to Union Chimique Belge’s BIMZELX, a U.S. Food & Drug Administration-approved monoclonal antibody for the same indication, the complaint alleges.
False and Misleading Statements
The MoonLake class action lawsuit alleges that defendants throughout the Class Period made false and/or misleading statements and/or failed to disclose that:
- (i) SLK and BIMZELX share the same molecular targets (the inflammatory cytokines IL-17A and IL-17F);
- (ii) SLK’s distinct Nanobody structure would not confer a superior clinical benefit over the traditional monoclonal structure of BIMZELX; and
- (iii) SLK’s distinct Nanobody structure supposed increased tissue penetration would not translate to clinical efficacy.
Corrective Disclosure
The MoonLake class action lawsuit alleges that on September 28, 2025, MoonLake announced 16-week results from its Phase 3 VELA program which showed that SLK failed to demonstrate competitive efficacy relative to BIMZELX. On this news, the price of MoonLake stock fell nearly 90%, according to the complaint.
Shareholders in a securities class action lawsuit can choose to join the class action and receive a portion of the settlement, or they can “opt out” to pursue an independent, direct action against the company.
Options also include selling the right to a recovery, and, in some cases, investors may be able to influence the lawsuit by voting on certain proposals, although the latter is less common and not always an option.
- Join the MoonLake class action lawsuit:
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- This is the default option for eligible investors.
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- What it is: You are included in the lawsuit and share in the recovery from a settlement.
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- Considerations: Recovery can be small (average of about 2% of losses), and payouts can take a long time due to the length of the class action and claims administration process.
- Opt out of the MoonLake class action lawsuit:
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- This allows you to pursue a direct, individual claim.
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- What it is: You are no longer part of the class and are not bound by the class action’s settlement or outcome.
- Sell the claim:
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- It is possible to sell your right to the class action settlement recovery.
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- What it is: You can transfer the right to the future payout to a third party in exchange for a smaller, immediate payment.
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- Considerations: This can provide immediate liquidity, but you will not receive any money from the class action settlement.
- Vote on proposals (less common):
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- In some instances, shareholders may have the opportunity to vote on proposals related to the class action.
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- What it is: These are typically “ex ante” proposals before a lawsuit is filed or “ex post” proposals after a lawsuit is filed.
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- Considerations: The ability to vote is not guaranteed and depends on the specific circumstances of the lawsuit and the company.


