REGN

⬣ Class Action

Regeneron Pharmaceuticals, Inc.

Securities Class Action Lawsuit

What Is the Regeneron Pharmaceuticals, Inc. (REGN) Class Action Lawsuit About?

Bronstein, Gewirtz & Grossman, LLC notifies investors that a class action lawsuit has been filed against Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) and certain of its officers.

This lawsuit seeks to recover damages against Defendants for alleged violations of the federal securities laws on behalf of all persons and entities that purchased or otherwise acquired Regeneron securities between August 1, 2025, and May 15, 2026, both dates inclusive (the “Class Period”). Such investors are encouraged to join this case.

What Does the Regeneron Pharmaceuticals, Inc. Securities Class Action Allege?

The Complaint alleges that, throughout the Class Period, Defendants made materially false and/or misleading statements and/or failed to disclose that:

  1. the preliminary statistical assumptions underlying Regeneron’s Phase III Fianlimab-Libtayo study were fundamentally flawed;
  2. the study’s active treatment arm was not demonstrating meaningful clinical differentiation from standard therapies;
  3. the study was unlikely to achieve statistical significance with respect to its primary endpoint, even absent overperformance by the control arm; and
  4. as a result, the Company’s statements regarding the study’s design, progress, and prospects were materially false and/or misleading at all relevant times.

What’s Next for Regeneron Investors?

A class action lawsuit has already been filed. You may review a copy of the Complaint. You may also contact Peretz Bronstein, Esq. or his Client Relations Manager, Nathan Miller, of Bronstein, Gewirtz & Grossman, LLC: 917-590-0911. If you suffered a loss in Regeneron you have until September 14, 2026, to request that the Court appoint you as lead plaintiff. Your ability to share in any recovery doesn’t require that you serve as lead plaintiff.

How Did Regeneron Pharmaceuticals, Inc. (REGN) Stock React to the Disclosures?

Filed Complaint

Review the full class action complaint as filed in court.

View PDF

How Is BG&G Representing Investors in Securities Class Actions?

We represent investors in class actions on a contingency fee basis. That means we will ask the court to reimburse us for out-of-pocket expenses and attorneys' fees, usually a percentage of the total recovery, only if we are successful.

Bronstein, Gewirtz & Grossman, LLC is a nationally recognized firm that represents investors in securities fraud class actions and shareholder derivative suits. Our firm has recovered hundreds of millions of dollars for investors nationwide.

“Our practice centers on restoring investor capital and ensuring corporate accountability, which serves to uphold the essential integrity of the marketplace.”
— Peretz Bronstein, Founding Partner

The deadline for lead plaintiff for this case has passed.

Thank you for your interest.