Biogen (BIIB) Stock News Today (Dec. 22, 2025): QALSODY Data, Nasdaq-100 Exit, and Analyst Forecasts
Biogen Inc. (NASDAQ: BIIB) is in focus on Monday, December 22, 2025—a day that combines company-specific clinical headlines with a major index event for the stock. Investors are weighing fresh long‑term data for QALSODY (tofersen) in a rare genetic form