The Gross Law Firm notifies investors that a class action has commenced in the United States District Court for the Southern District of New York on behalf of shareholders of Regeneron Pharmaceuticals, Inc. who purchased common stock between August 1, 2025 and May 15, 2026.
According to the complaint, defendants provided overwhelmingly positive statements to investors while, at the same time, disseminating materially false and misleading statements and/or concealing material adverse facts concerning the true state of Regeneron’s Phase III Fianlimab-Libtayo Study; notably, that its preliminary statistical assumptions were fundamentally flawed, that the active treatment arm was failing to achieve meaningful clinical differentiation over standard therapies, and that the trial would ultimately fail to reach statistical significance on its primary endpoint even without overperformance of the control arm. On April 29, 2026, during Regeneron’s first quarter earnings call, defendants disclosed the Phase III Fianlimab-Libtayo Study had been altered, expanding the number of patients in the study eligible for “analysis of progression-free survival.” Following this news, the price of Regeneron’s common stock declined dramatically. From a closing market price of $731.77 per share on April 28, 2026, Regeneron’s stock price fell to $686.36 per share on April 29, 2026, a decline of about 6.2% in the span of just a single day. On May 15, 2026, Regeneron issued a press release announcing that the “Phase 3 Trial of Fianlimab . . . did not reach statistical significance for the primary endpoint of improvement in progression-free survival (PFS).” Following this news, the price of Regeneron’s common stock declined even further. From a closing market price of $698.25 per share on May 15, 2026, Regeneron’s stock price fell to $629.68 per share on May 18, 2026, a decline of about 9.8% in the span of one day.
If you wish to choose counsel to represent you and the class, you must apply to be appointed lead plaintiff and be selected by the Court. The lead plaintiff will direct the litigation and participate in important decisions including whether to accept a settlement for the class in the action. The lead plaintiff will be selected from among applicants claiming the largest loss from investment in the respective securities during the class periods. Members of the class will be represented by the lead plaintiff and counsel chosen by the lead plaintiff. No class has yet been certified in the above action. Appointment as Lead Plaintiff is not required to partake in any recovery.
Shareholders have until September 14, 2026 to request that the court appoint them lead plaintiff.
To receive more information, please fill out the form.
