Monday's BBC Panorama episode, "Alzheimer's: A Turning Point?", put two drugs at the centre of the story: lecanemab and donanemab. Trial results over the past two years have shown both can slow the progression of early Alzheimer's disease, the most common cause of dementia. Neither is currently licensed for prescription in the UK outside clinical trials, though decisions on that are expected within months.
The BBC's Medical Editor, Fergus Walsh, met people receiving the drugs as trial participants. Among them was Dawn, 62, from Hampshire, who is taking donanemab and said that if the drug slows her disease, she will be able to function as she would like and do some of the things she still wants to do. That framing captures what these treatments offer at present: not reversal or cure, but time spent at a higher level of ability.
Dr Cath Mummery, consultant neurologist and Head of Clinical Trials at University College London's Dementia Research Centre, was clear with Walsh that the effects are modest. Across 18 months, the drugs appear to slow cognitive decline by roughly a quarter to a third. Translated into everyday terms, she said, that amounts to about five months of higher functioning - a difference she described as meaningful for the individual patient, even if the trial statistics look undramatic.
The gap between a statistically significant slowing of decline and a change a family would actually notice is the question regulators and health services now have to weigh. For people in the UK living with early Alzheimer's, the practical issue is not only whether these drugs work, but whether and how they will become available outside a trial setting - something the coming licensing decisions should start to answer.