"Biogen's Alzheimer's Drug Approval Sends Stock on a Rollercoaster Ride"

Biogen's stock fell after the FDA granted full approval for its Alzheimer's treatment, Leqembi. The approval allows Medicare to reimburse patients for the cost of the treatment, but doctors will need to submit patient data to a registry database. Analysts are divided on how quickly Biogen and partner Eisai can ramp up the drug. The approval comes with a black box warning for a heightened risk of brain swelling in certain patients, and the FDA recommends genetic testing prior to treatment. Biogen's ability to expand the use of Leqembi will depend on securing coverage from other payers, as Medicare only covers patients with early Alzheimer's disease.