Regeneron Pharmaceuticals faces a securities class-action lawsuit regarding its Phase III trial for a melanoma treatment combining fianlimab and Libtayo. The complaint alleges the company made materially false statements and failed to disclose critical issues with the trial’s design and statistical assumptions. These omissions reportedly created a false impression of the study’s potential for success.
Investors have until September 14, 2026, to seek lead plaintiff status in the case. Multiple law firms issued notices following stock price drops earlier this year.
The stock declines occurred after Regeneron announced changes to the study and its eventual failure to meet the primary endpoint. This legal challenge places the company’s oncology pipeline and disclosure practices under increased scrutiny.