A new drug, Donanemab, is being hailed as a turning point in the fight against Alzheimer’s, after a global trial confirms it slows cognitive decline. The antibody medicine helps in the early stages of the disease by clearing a protein that builds up in the brains of people with this type of dementia. Although not a cure, charities say the results in the journal JAMA mark a new era where Alzheimer’s can be treated.