The complaint filed in the Southern District of New York alleges that Regeneron mischaracterized a slowdown in progression-free survival event accrual, framing it as evidence of durable treatment efficacy rather than a warning sign of statistical failure. According to the filing, the company failed to disclose that initial statistical assumptions for the melanoma study were flawed, leaving the trial at an increased risk of missing its primary endpoint.

Regeneron shares dropped approximately 13.95%—a decline of $102.09 per share—following disclosures related to the trial’s protocol and its ultimate failure to achieve statistical significance. Levi & Korsinsky, LLP, the firm representing the class, argues that these omissions prevented investors from accurately assessing the risk profile of the program. The suit seeks to recover losses for shareholders who acquired securities during the specified class period, regardless of whether they currently hold the shares.