From the ‘Alzheimer’s Society
There are 143 drugs being tested in clinical trials for the treatment of Alzheimer’s disease. Over 80% of these drugs are designed to try and slow down how quickly Alzheimer’s gets worse and progresses. We examine the three most promising drugs, lecanemab, gantenerumab and donanemab and summarise their journey so far.
What drugs are there for people living with Alzheimer’s disease?
Alzheimer’s disease causes the cells in the brain to get sick and eventually die, which leads to symptoms like memory loss.
To treat Alzheimer’s disease, we need to find effective drugs that are able to slow down or stop it. These drugs are often called ‘disease-modifying’ treatments.
At present, there are no disease-modifying treatments available in the UK for any type of dementia, including Alzheimer’s disease.
To date, there hasn’t been a new drug approved for Alzheimer’s disease in 20 years.
Existing drugs only treat the symptoms of Alzheimer’s disease. They do not treat the root cause of the disease and so do not slow down how quickly it gets worse.
A new type of treatment
In the brains of people living with Alzheimer’s disease, a protein called amyloid builds up into plaques. These plaques are thought to be toxic and damage the cells of the brain.
It was Alzheimer’s Society-funded research led by Sir Professor John Hardy that first showed the importance of amyloid protein’s role in the causes of Alzheimer’s disease over 30 years ago.
Researchers have gone on to develop drugs which are able to clear amyloid from the brain. These drugs are called immunotherapies. They target the amyloid plaques in the brains of people with Alzheimer’s disease to try and help break them down.
Immunotherapies are already used in medicine, for example in the treatment of some cancers.
Researchers believe that by clearing amyloid plaques from the brain, they will be able to slow down how quickly Alzheimer’s disease gets worse.
Here we explore three drugs that work in this way and have shown promise as treatments for Alzheimer’s disease.
1. Lecanemab and Alzheimer’s disease
What is lecanemab?
Lecanemab (sometimes called BAN2401) is an immunotherapy drug. It is designed for people living with early-stage Alzheimer’s disease.
The drug is given to patients intravenously, which means by injection into a vein.
What’s the latest development with lecanemab?
Lecanemab made headlines in September 2022 when top-line results from a final stage clinical trial called Clarity-AD were released.
Progress with new Alzheimer’s drug lecanemab announced
Lecanemab (sometimes called BAN2401) is an immunotherapy drug. It is designed for people living with early-stage Alzheimer’s disease.
The drug is given to patients intravenously, which means by injection into a vein.
What’s the latest development with lecanemab?
On the 27th September, Eisai Co. Ltd. and Biogen announced top-line results for a major trial on the drug lecanemab in slowing down the progress of Alzheimer’s disease. The results showed that lecanemab treatment slowed down the decline in thinking and memory skills in people living with early Alzheimer’s disease by 27%. They also showed that lecanemab effectively removed amyloid protein from the brains of people taking the drug.
This news represents a potentially game-changing step towards treatments that can slow down the progression of Alzheimer’s disease. We won’t know the complete picture until the full results from the trial are released on 29 November 2022.
Where could lecanemab become available?
Before lecanemab can become available for use it will have to be approved as a safe and effective treatment by drug regulatory bodies.
United States of America
Eisai (the company that makes lecanemab) has submitted the drug for approval to the US Food and Drug Administration (FDA). The FDA is expected to make a decision on whether to approve lecanemab for use in the United States by January 2023.
Europe
Lecanemab has also been submitted to Europe’s European Medicines Agency (EMA). We expect the EMA to make a recommendation on whether lecanemab should be approved for use in Europe sometime in 2023.
United Kingdom
For lecanemab to be available in the UK, it would have to be approved by the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK. We do not yet know whether lecanemab has been submitted to the MHRA.
2. Gantenerumab and Alzheimer’s disease
What is gantenerumab?
Gantenerumab is an immunotherapy drug. It is designed for people living with early-stage Alzheimer’s disease.
The drug is given to patients by injection.
What’s the latest development with gantenerumab?
Gantenerumab was first tested in two clinical trials called Scarlet RoAD and Marguerite RoAD in people with mild Alzheimer’s disease.
Unfortunately, data from the initial clinical trials didn’t show evidence of benefit in memory and thinking skills.
The trials were extended so that people could continue to take the drug.
During this extension, it was found that a high dose of the drug reduced the amount of amyloid protein in the brains of the people taking it.
Join Dementia Research is a UK-based service that allows people to register their interest in taking part in dementia research.
Gantenerumab has also been tested in people who carry a gene that means they will go on to develop inherited Alzheimer’s disease. This is an incredibly rare type of Alzheimer’s disease which makes up less than 1% of total cases. In this trial, gantenerumab greatly reduced the amount of amyloid protein in the brains of the people taking it.
However, gantenerumab treatment did not delay the start of symptoms of inherited Alzheimer’s disease in people taking the drug. This trial was also extended in 2020 and will measure the effects of gantenerumab treatment over the following three years.
Gantenerumab is currently being tested in two final stage trials called GRADUATE 1 and 2. These trials are being carried out worldwide and include a total of 1,966 people living with early-stage Alzheimer’s disease.
We expect to hear more results from these two trials in November 2022.
3. Donanemab and Alzheimer’s disease
What is donanemab?
Donanemab is an immunotherapy drug. It is designed for people living with early-stage Alzheimer’s disease.
The drug is given to patients intravenously, by injection into a vein.
What’s the latest development with donanemab?
In 2021, top-line results for donanemab were released from a clinical trial called TRAILBLAZER-ALZ involving people who had amyloid protein plaques in their brains and memory and thinking problems.
The truth about clinical trials: 5 big myth busters.
Initial results showed that treatment with donanemab slowed down the decline in memory and thinking skills by up to 32%.
Later results of clinical trials showed that the amyloid plaques were broken down quickly during the first six months of treatment with donanemab.
A final stage trial for donanemab called TRAILBLAZER-ALZ 2 is being carried out. The trial includes 1,625 people who have amyloid plaques in their brains and symptoms of memory and thinking problems. We expect the results from this trial to be released in the first half of 2023.
Several other trials are being conducted with donanemab. A trial called TRAILBLAZER-ALZ 3 is exploring whether donanemab treatment can delay or prevent the development of Alzheimer’s disease.
Another trial called TRAILBLAZER-ALZ4 is comparing donanemab treatment to that of another anti-amyloid drug called aducanumab, which is currently only approved for treatment of Alzheimer’s disease in the United States.
What does this mean for people living with Alzheimer’s disease in the UK?
It is an incredibly exciting and hopeful time for dementia research, with results from lecanemab, gantenerumab and donanemab expected over the next 12 months.
These trials will teach us a great deal about the benefits of removing amyloid protein from the brain using immunotherapies.
For any drug to become available in the UK, it must be approved by the MHRA. The MHRA scrutinise the clinical trial data of every drug and use this data to determine whether the drug is safe and effective as a treatment.
What research is Alzheimer’s Society funding?
Could a new Alzheimer’s disease drug become available on the NHS?
For a drug to be available on the NHS, it would also need to be approved by the National Institute for Health and Care Excellence (NICE).
For this decision, NICE will take into account how cost-effective a treatment is.
Lecanemab, gantenerumab and donanemab represent the exciting first steps in our journey to develop new treatments to slow down and stop the diseases that cause dementia.
However research can’t stop here. There are many different diseases of the brain that cause dementia, with each disease affecting brain cells in different ways.
It is absolutely crucial that research continues to uncover what is going wrong inside the brain.
With this knowledge, researchers will develop new, innovative treatments to tackle every type of dementia.
Alzheimer’s Society is committed to continue investing in the best researchers who will go on to develop improved, targeted treatments that will someday benefit everyone living with dementia.
