Research

What is donanemab?

The Medicines and Healthcare products Regulatory Agency (MHRA) has approved donanemab (marketed as Kisunla in the UK) as a treatment for some people with early-stage Alzheimer’s disease. The drug can slow down the decline in memory and thinking skills of people living with early Alzheimer’s disease.

Following an extended consultation, the National Institute for Health and Care Excellence (NICE) has published its final guidance, where its recommendation remains that donanemab not be provided through the NHS. 

Another similar drug called lecanemab (marketed as Leqembi) has also been approved by the MHRA. Similarly, the final guidance from NICE is that lecanemab will not be provided through the NHS. 

What is donanemab?

Donanemab (brand name Kisunla) is a disease-modifying drug, which means that it was developed to tackle the causes of Alzheimer’s disease rather than only relieving the symptoms.  

Donanemab is given to patients intravenously, which means into a vein through a drip bag. It is an immunotherapy drug developed by a pharmaceutical company called Eli Lilly. Immunotherapy drugs are already used in medicine for treating different diseases, like cancers. They tell the body’s immune system to attack foreign cells or proteins and get rid of them so they can’t cause any more problems.

In the case of donanemab, it teaches the immune cells to recognise and remove a protein called amyloid, which builds up in the brains of people with Alzheimer’s disease. In the trial three-quarters of the people taking donanemab had amyloid successfully cleared from their brains by the end of the trial.

The amyloid protein build-ups are thought to be toxic to brain cells, causing them to get sick and eventually die, leading to the symptoms of Alzheimer’s disease. The importance of this protein in the development of Alzheimer’s disease was discovered by Alzheimer’s Society-funded research led by Professor Sir John Hardy over thirty years ago. It laid the foundations for billions of pounds of investment into many drugs like donanemab, with over 130 other drugs currently being tested in clinical trials.

Does donanemab work?

Donanemab slowed how fast memory and thinking get worse by more than 20%. The evidence from a trial called TRAILBLAZER ALZ2 showed that the earlier in the disease the treatment was given, the greater the benefit. This meant that there was more slowing in memory and thinking decline in people with fewer changes in their brains associated with Alzheimer’s disease at the start of the trial.

Also, after one year on donanemab, nearly half of the people taking it had no decline in memory and thinking skills.  

People taking donanemab had a 40% reduction in the decline of their ability to carry out daily activities, such as managing finances, driving and carrying out hobbies.  

These are exciting results, but we don’t fully know what this will mean in the long term for people who have taken donanemab as the trial only lasted 18 months.  

Also, 91.5% of the participants in the trial were from a white background, so we need more diversity in clinical trials to prove that these drug treatments will work for everyone with early Alzheimer’s disease. 

Is donanemab safe?

As well as testing the effectiveness of donanemab, clinical trials also tested the safety of the drug, by monitoring for bad side effects.

As with all drug treatments, there have been some side effects associated with donanemab.  

These included headaches, reactions to the intravenous drip, and swelling or microbleeds in the brain known to be related to amyloid.

The vast majority of side effects (82.4%) were either mild or were detected in tests but didn’t cause any symptoms.

Data from the main trial and its extension showed that altogether, 15% of participants had a serious side effect. 2.9% of people had a serious side effect related to Amyloid-Related Imaging Abnormalities (ARIA), which can include swelling or bleeding on the brain, and the remaining 12.9% of people had a serious side effect related to something other than ARIA. 

Unfortunately, there were three deaths in the trial related to the treatment. 

How can I access donanemab?

After reviewing the data and evidence, the MHRA have concluded that donanemab is safe and beneficial to people with early Alzheimer’s disease and will be approved for use in the UK under the brand name Kisunla.  

Donanemab has only been approved for some people with early-stage Alzheimer’s disease, excluding:  

• People with moderate or late-stage Alzheimer’s disease  
• Those with other types of dementia such as dementia with Lewy bodies, vascular dementia or frontotemporal dementia  
• People who carry two copies of the APOE4 gene variant as these individuals are at a greater risk of side effects  

Donanemab may be available from some private health providers.  

To be eligible for donanemab treatment a person would need to be in the early stages of Alzheimer’s disease and have amyloid protein buildup present in their brain. This is shown using amyloid PET scans or testing of spinal fluid.

It is also likely people will need to have a genetic test to learn whether they have the APOE4 variant. 

Will donanemab be available on the NHS?

The National Institute for Health and Care Excellence (NICE) decide which medicines should be made available on the NHS. Whilst the MHRA has approved donanemab, guidance from NICE has not recommended it for use on the NHS as donanemab didn't meet NICE's cost effectiveness threshold.

What does this mean for the future and for people affected by dementia?

The NICE recommendations for lecanemab and donanemab is of course, a setback for people with dementia who might have been eligible.

We still believe we are heading towards a future where disease-modifying treatments reduce the devastation caused by dementia and there are three steps that will be critical for preparing for new treatments. 

Firstly, the UK government must commit to long-term investment to transform dementia diagnosis. Donanemab is most effective in the early stages of disease, therefore it is important to diagnose Alzheimer’s disease early. The reality is that, if a disease-modifying treatment was approved for use on the NHS tomorrow, too many people with dementia wouldn’t be able to access it as currently more than a third of people with dementia don’t get a diagnosis. 

Secondly, we will be encouraging NICE, and relevant research and clinical communities, to identify learnings from the process of assessing these first disease-modifying treatments.

And thirdly, it is important that real world data from private access to lecanemab and donanemab in the UK is collected and that learnings from implementation of these treatments in other countries are shared, to improve our understanding of the drugs’ effectiveness and safety in real world populations. 

Research will beat dementia. It’s important to recognise that lecanemab and donanemab are first generation treatments, and in other conditions we have seen treatments become cheaper, safer and more effective as research continues. We hope to see similar progress in Alzheimer's disease in the months and years ahead.

How can you get involved in dementia research?

Alzheimer’s Society is a partner in a service called Join Dementia Research (JDR). The service allows anyone over the age of 18 to register their interest in participating in dementia research; however, researchers are particularly keen to hear from those with a diagnosis of dementia/ or MCI and those that care/support them to register.

If you would like to hear more about this service then please contact our Join Dementia Research helpdesk by calling 0333 150 3456 and asking for the Join Dementia Research helpdesk or emailing us directly at: joindementiaresearch@alzheimers.org.uk.

We will update this page as new information becomes available. Last updated: 19 June 2025