Biogen Stung as U.S. Limits Coverage of Alzheimer’s Therapy (4)

The U.S. government limited Medicare coverage of Biogen Inc.’s Alzheimer’s disease treatment and similar drugs to patients enrolled in clinical trials, a highly unusual move that will curb access to the controversial treatment approved last year.

Coverage of Biogen’s therapy, sold under the brand name Aduhelm, and other amyloid-targeted Alzheimer’s therapies, will be limited to people participating in qualified clinical trials, the Centers for Medicare & Medicaid Services said Tuesday in a statement. The shares fell 10% Wednesday before U.S. markets opened and have lost almost 40% since the drug’s June 7 approval.

The decision is preliminary and will ...