A new drug has been hailed as a scientific breakthrough in treating Alzheimer’s disease, following the publication of final trial results in the medical journal, JAMA. 

The findings show donanemab can successfully slow down decline in memory and thinking by 35 per cent among people with early-stage Alzheimer’s Disease. The drug’s ability to slow down cognitive impairment allowed people to continue to perform day-to-day tasks such as shopping, taking medication and managing their finances.

The results from the TRAILBLAZER-ALZ 2 Phase 3 trial showed that donanemab is successful in removing sticky plaques from the brain. It was able to slow progression on a measure of cognition and function in people with  Alzheimer’s by disease by approximately 35 per cent. The trial involved nearly 1,800 people with early-stage Alzheimer’s Disease.

Donanemab is made by US pharmaceutical company Eli Lilly, who have applied for approval in the US and is expected to do so in the UK in the coming months.

Donanemab is an immunotherapy drug, which uses the body’s immune system to remove foreign proteins. It is believed these types of drugs are effective in people with early-stage Alzheimer’s, rather than those with a moderate or severe condition.

Three UK participants were recruited to the study through Join Dementia Research, which also took place in Australia, Canada, Czech Republic, Japan, Netherlands, Poland and the United States.

The findings also confirmed some potentially serious side-effects of the drug. Some 24 per cent of people on the trial receiving donanemab were reported to have experienced side effects. This included brain swelling and infusion-related reactions. Four participants died during the trial, with their deaths thought to be related to the drug’s side effects. 

NIHR Clinical Research Network National Specialty Lead for Dementia, Prof John O’Brien, said recent studies showing this group of drugs could modify progress of the disease was a scientific “breakthrough”.

He added that without people taking part in clinical research studies, such as those available via Join Dementia Research, the advancement would not have been possible.

Prof O’Brien said: “The study results reported this week on donanemab, showing that the drug can significantly reduce amyloid levels in the brain, and slow disease progression clinically by 20 to 35 per cent over 18 months, are extremely important and exciting. 

“They add to other recent evidence from trials of similar agents, aducamemab and lecanemab, showing that amyloid levels can be lowered, and that this is accompanied by clinical benefit.

“These are the first group of drugs shown to modify the underlying disease process, which is a real breakthrough.

“Some caution is needed as the drugs require regular infusions, the clinical benefits are modest, and these agents won’t be suitable for most people with Alzheimer’s disease. There are also serious and potentially fatal side effects, meaning that – if the drugs become licensed and available – people taking them would need very careful monitoring.

“However, the important proof of principle these agents provide, is a key first step to getting better treatments for Alzheimer’s disease and other dementias, which can then be applied more widely. 

“This would not have been possible without people taking part in clinical research studies, such as those available via Join Dementia Research.”

In 2022, trials into another immunotherapy drug, lecanemab, showed the drug slowed down the decline in memory and thinking skills of people living with early Alzheimer’s disease by 27 per cent.

Join Dementia Research volunteers also took part in the study into lecanemab and helped test the new drug.

Join Dementia Research is a free, national service that enables you to register your interest and be matched with suitable research studies.

To find out about other dementia studies, sign in to your Join Dementia Research account or if you are not already registered, sign up today.