Biogen Surges After FDA Reviewers Support Alzheimer’s Drug (2)

Biogen Inc.’s experimental Alzheimer’s disease therapy appears effective despite conflicting clinical-trial results, according to a report by staff of the U.S. Food and Drug Administration, a positive sign that a drug the company once wrote off could gain approval.

The treatment, called aducanumab, has had a circuitous journey toward its possible clearance. Biogen halted its study of the drug in March 2019 on signs it wouldn’t work, then revived it in October that year after it said a review of data in one of two trials showed it was successful.

FDA staff said Wednesday that aducanumab’s effect was “robust ...