Could a new treatment developed by the US company Lilly mean "the beginning of the end" of Alzheimer's? Could we even cure it some day? These are headlines and questions swirling （流传） around after news of a new drug, called donanemab, showed promising results in phase-3 trials.
The brain science behind Alzheimer's is complex, but CT and MRJ scans suggest that poisonous changes occur in the brain, including the abnormal build-up of proteins called amyloid plaques and tau tangles. The damage starts in the parts of the brain essential for forming memories but then spreads throughout the organ, with brain tissue shrinking significantly.
Developing treatments for Alzheimer's has been a challenge, with almost 20 years passing with no new drugs. But in the last year, two new ones have emerged: donanemab and lecanemab. Neither are cures or magic bullets for the disease, but they do address key symptoms. They target the amyloid proteins that can accumulate in the brain and damage neurons, slowing down its progression.
While this news is exciting, there are major caveats. One is whether it will ever become available on the NHS. The cost is estimated to be about £20,000 per person per year of treatment.
Another is the serious side effects: in the study, brain swelling occurred in 24% of participants and brain bleeding occurred in 31.4% on the drug compared with 13.6% in the placebo （安慰剂） group. There were also three deaths during the trial.
Part of the problem for me, as an academic, in assessing the drug is that the full results of the trial haven't yet been shared publicly or published in a peer-review journal. We cannot access the full data or examine the trial yet, and there is always a motivation for private companies to overstate the effectiveness of new drugs. Trial results need to be assessed by an independent body of experts.
While it is unlikely to change clinical practice until at least 2025, the news of donanemab is again an indication that science is continuing to make progress when it comes to treating the major causes of illness and death, even one related to the highly complex inner workings of the brain. So, there are caveats and the need for caution, but these new drugs are indeed the grounds for that rare thing these days: hope.
