Key points from article :
Biogen halts development of Aduhelm, a once-promising Alzheimer's drug.
FDA approval conditional on additional study, deemed unlikely with future advancements.
Patients on Aduhelm can continue treatment until November.
Biogen shifts focus to other Alzheimer's treatments, including Leqembi.
Leqembi is the first drug proven to slow cognitive decline, but only modestly.
Aduhelm faced controversy for its high price, weak evidence, and limited access.
Company expects a $60 million charge for shutting down the Aduhelm program.
