Groundbreaking Drug Donanemab Demonstrates Promise in Slowing Alzheimer’s Cognitive DeclineA revolutionary drug known as donanemab is being hailed as a significant breakthrough in the battle against Alzheimer’s disease, as a global trial has confirmed its efficacy in slowing cognitive decline. This antibody medicine proves effective in the early stages of the disease by clearing a specific protein that accumulates in the brains of individuals with this form of dementia.
While not a cure, the findings published in the journal JAMA are seen as a pivotal moment in Alzheimer’s treatment, offering hope for a new era where the disease can be effectively managed. The UK’s drugs watchdog has commenced its assessment for potential inclusion in the NHS.
It is important to note that donanemab targets Alzheimer’s disease and is not applicable to other types of dementia, such as vascular dementia. In the clinical trials, the drug demonstrated the ability to slow the progression of the disease by approximately one-third, granting patients the opportunity to maintain more of their daily activities and responsibilities, like cooking and pursuing hobbies.
Among the fortunate few to participate in the global trial is 80-year-old Mike Colley, who receives monthly infusions at a London clinic. He describes himself as “one of the luckiest people you’ll ever meet,” having witnessed the positive impact of the treatment on his cognitive function and overall well-being.


Shortly before Mike Colley joined the donanemab trial, he and his family noticed concerning signs of memory and decision-making problems. His son, Mark, described how difficult it was to witness his father struggling with information processing and problem-solving. However, they now believe his cognitive decline has reached a plateau, providing some relief.
Hailing from Kent, Mike expressed growing confidence in his condition with each passing day, attributing it to the effects of the drug donanemab. Developed by Eli Lilly, donanemab operates similarly to lecanemab, a drug jointly created by Eisai and Biogen, which gained global attention for its success in slowing the progression of Alzheimer’s disease.
While the potential of these drugs is promising, it is crucial to acknowledge that they come with risks. Brain swelling was observed in a significant number of patients during the donanemab trial, although most experienced resolution without symptoms. Tragically, two volunteers, and possibly a third, succumbed to dangerous swelling in the brain.
Moreover, European regulators recently rejected another antibody-based Alzheimer’s drug, aducanumab, citing safety concerns and insufficient evidence of its effectiveness for patients. These developments underscore the importance of careful evaluation and monitoring in the pursuit of effective treatments for this devastating disease.
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In the donanemab trial, researchers examined 1,736 people aged 60 to 85 with early-stage Alzheimer’s.Half of them received a monthly infusion of the treatment and the other half were given a dummy drug, also known as a placebo, over 18 months.The findings show:
- The drug seems to have a meaningful benefit, at least for some patients
- Those who had earlier disease and less brain amyloid at baseline derived greater benefit, in terms of clearance seen on brain scans
- Those given the drug also retained more of their day-to-day lives such as being able to discuss current events, answer the phone or pursue hobbies
- The pace of the disease, judged by what people could still do day-to-day, was slowed by about 20-30% overall – and by 30-40% in a set of patients who researchers thought more likely to respond
- There were significant side-effects and patients will need to be aware of risks of treatment
- Half of patients on donanemab were able to stop the treatment after a year, because it had cleared sufficient brain deposits
Amyloid is just one part of the complex picture of Alzheimer’s, and it is unclear if the treatment will continue to make more difference over a longer period, experts caution.

The publication of the full results confirming the effectiveness of donanemab in slowing cognitive decline in Alzheimer’s patients has been met with enthusiasm by experts and organizations in the field. They believe that while the drug’s effects may be modest, it provides further evidence that removing amyloid from the brain can alter the course of the disease and bring hope to those affected.
Prof Giles Hardingham of the UK Dementia Research Institute expressed his excitement over the tangible progress in Alzheimer’s treatment, emphasizing the long-awaited nature of such advancements. Dr Susan Kohlhaas from Alzheimer’s Research UK described the announcement as another significant milestone, indicating a changing outlook for dementia and the potential for Alzheimer’s disease to become treatable.Former Prime Minister David Cameron called for resources to be directed towards research for a “statin for the brain,” a pill that could clear the protein build-up associated with dementia and reduce the risk of developing the disease.
Mr. Cameron also expressed the need for government investment in new treatments, highlighting the potential cost savings and the opportunity to effectively treat individuals with dementia.The cost of lecanemab in the US is approximately $27,500, and it remains unclear how much donanemab will cost and how long it will take to obtain approval in the UK. However, experts in the field believe that having two drugs available will foster competition and potentially lead to more favorable pricing.
The UK’s National Institute for Health and Care Excellence (NICE) has already begun its appraisal of donanemab for the treatment of mild cognitive impairment or mild dementia caused by Alzheimer’s disease. NICE aims to provide recommendations for its use in the National Health Service (NHS) as soon as possible after receiving UK licensing.

Mike Colley’s 80th birthday celebration was marked by a surprising and confident performance, as he sang “My Way” in front of 40 guests. This newfound self-assurance is a testament to the positive impact of the donanemab trials he participated in.
Mike’s son, Mark, was moved by the transformation, stating that he never thought he would see his father so full of life again.Dr Emer MacSweeney, who led the UK trials of donanemab, described the breakthrough as one of the most significant in the fight against Alzheimer’s.
The Alzheimer’s Society also hailed the results, emphasizing that science is proving it is possible to slow down the disease. About 720,000 people in the UK could potentially benefit from these new treatments if approved for use.However, the charity raised concerns about the NHS’s readiness to deliver these treatments at scale.
Timely and accurate diagnosis is crucial, yet only a small percentage of people currently receive their diagnosis through specialist investigations required for eligibility for these treatments. Additionally, the emerging Alzheimer’s disease drugs necessitate regular infusions and monitoring, and the NHS infrastructure needs to be equipped to handle this demand.