Law firm investigates Biogen for possible securities fraud after Alzheimer's drug trial misses key goal.

Pomerantz LLP is investigating Biogen Inc. for potential securities fraud following the company's announcement that its Phase 2 trial for an Alzheimer's drug, diranersen, missed its primary endpoint despite being described as "compelling." The news caused Biogen's stock to drop over 6% on May 14, 2026. The investigation targets whether Biogen and its executives engaged in unlawful business practices, with investors encouraged to join a class action lawsuit. This case highlights risks around clinical trial disclosures and their impact on stock prices.