Institutional investors with REGN positions may need to assess alleged clinical-trial disclosure failures that preceded a $102.09 per-share decline from the Class Period high. This notice focuses on fiduciary review, portfolio loss documentation, and lead plaintiff considerations.

NEW YORK, Aug. 6, 2026 /PRNewswire/ –SueWallSt notifies institutional investors in Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) that a class action has been filed on behalf of shareholders who purchased securities between August 1, 2025 and May 15, 2026. Find out if you might be eligible to recover losses. You may also contact Joseph E. Levi, Esq. at jlevi@SueWallSt.com or (888) SueWallSt.

REGN declined from $731.77 on April 28, 2026 to $629.68 after the May 15, 2026 disclosure, a $102.09 per-share decline, or approximately 13.95%. The lead plaintiff deadline is September 14, 2026.

Institutional Investor Securities Recovery ERISA Review

The complaint alleges Regeneron presented an overly optimistic picture of its Phase III Fianlimab-Libtayo Study disclosures while minimizing the risk that a prolonged slowdown in progression-free survival event accrual reflected deeper statistical problems. For pension funds, asset managers, endowments, and other fiduciaries, the issue is practical: whether portfolio losses during the Class Period warrant evaluation for potential recovery.

Fiduciary Obligations and Recovery Options

Institutional holders often evaluate securities claims through documentation, governance, and loss-size lenses. In this matter, the pleading asserts that alleged misstatements about clinical-trial risk affected the market price of REGN shares before the later disclosures.

• Review purchases and sales of REGN common stock during August 1, 2025 through May 15, 2026.
• Identify shares retained through the April 29, 2026 protocol-amendment disclosure and the May 15, 2026 failed-endpoint announcement.
• Preserve investment committee materials, manager reports, and trade confirmations tied to REGN positions.
• Compare realized and unrealized losses against fiduciary thresholds for monitoring securities litigation recoveries.
• Consider whether a lead plaintiff role aligns with portfolio size, governance policies, and oversight objectives.

Portfolio Impact Assessment for REGN Holders

As detailed in the action, Regeneron disclosed on April 29, 2026 that the Phase III study protocol had been altered to expand the patient population eligible for progression-free survival analysis. The Company later announced that the trial did not reach statistical significance on its primary endpoint, after which REGN shares declined further.

“Institutional investors play a critical role in securities class actions. In this Regeneron matter, fiduciaries may wish to evaluate whether alleged clinical-trial disclosure failures affected portfolio decisions, documented losses, and potential recovery options.” — Joseph E. Levi, Esq.

Click here to submit your information and learn more about the case or call (888) SueWallSt.

WHY SUEWALLST: SueWallSt is powered by Levi & Korsinsky LLP. Levi & Korsinsky LLP has established itself as a nationally-recognized securities litigation firm that has secured hundreds of millions of dollars for aggrieved shareholders and built a track record of winning high-stakes cases. The firm has extensive expertise representing investors in complex securities litigation and a team of over 70 employees to serve our clients. For seven years in a row, Levi & Korsinsky has ranked in ISS Securities Class Action Services’ Top 50 Report as one of the top securities litigation firms in the United States.

Frequently Asked Questions About the REGN Lawsuit

Q: What is the REGN class action lawsuit about? A: A securities class action has been filed against Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) alleging materially false and misleading statements between August 1, 2025 and May 15, 2026. Shares fell approximately 13.95% from the Class Period high after the Company disclosed a protocol amendment and later announced that the Phase III Fianlimab-Libtayo Study did not reach statistical significance for its primary endpoint. Investors who purchased shares during the Class Period and suffered losses may be eligible to seek compensation.

Q: Who is eligible to join the REGN investor lawsuit? A: Investors who purchased REGN stock or securities between August 1, 2025 and May 15, 2026 and suffered financial losses may be eligible. Eligibility is based on purchase date and documented losses, not on whether you still hold the shares.

Q: What specific misstatements does the REGN lawsuit allege? A: The complaint alleges Regeneron made materially false or misleading statements regarding the risk of clinical failure in the Phase III Fianlimab-Libtayo Study, including statements that allegedly framed slowing event accrual as potentially favorable when the trial allegedly faced increased statistical and clinical risk. When the protocol amendment and failed primary endpoint were disclosed, the stock price declined sharply.

Q: What court was the REGN class action filed in? A: The case was filed in the United States District Court for the Southern District of New York, governed by the Private Securities Litigation Reform Act of 1995.

Q: What is a lead plaintiff and why does it matter? A: A lead plaintiff is the investor appointed by the court to represent the entire class. Lead plaintiffs are typically investors with the largest documented losses. Being appointed does not increase individual recovery but gives direct oversight of how the case is run.

Q: What documents do I need for a loss review? A: Brokerage statements or trade confirmations showing purchase dates, share quantities, prices paid, and any subsequent sale dates and prices.

Q: What if I already sold my REGN shares, can I still recover losses? A: Yes. Eligibility is based on when you purchased, not whether you still hold the shares. Investors who bought during the Class Period and sold at a loss may still be eligible to participate.

Q: Do I need to go to court or give testimony? A: No. The overwhelming majority of class members never appear in court or give depositions. If there is a settlement or recovery, eligible class members generally submit a claim form to seek their portion.

CONTACT:
Levi & Korsinsky, LLP
Joseph E. Levi, Esq.
33 Whitehall Street, 27th Floor
New York, NY 10004
jlevi@SueWallSt.com
Tel: (888) SueWallSt
Fax: (212) 363-7171

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SOURCE SueWallSt.com