Potential Alzheimer’s treatment, trontinemab, hits the news – how does it work and is it available?

Four years ago, the results of a trial for lecanemab marked a turning point. They showed for the first time that Alzheimer’s disease can be slowed by medication. Not long after, another drug called donanemab followed with similar results.

In 2026, there are over 150 drugs in clinical trials across the world. More than ever, there is hope that real change is coming – hope that people who develop dementia in the future won’t face the same realities as they sadly do today.

Some of that hope is resting on the results of what could be the second generation of Alzheimer’s treatments. In particular, a new drug called trontinemab has recently hit the headlines following some promising early results. But we won’t know for sure how well the drug works until at least 2028, when current trials are due to end. Read on to find out if you could help scientists to find out whether this drug could be life-changing for people affected by dementia.

What is trontinemab?

Trontinemab is a potential new Alzheimer’s drug made by the pharmaceutical company Roche. It is still in development, with a trial due to start in autumn 2025.

Early data from smaller trials suggests that this drug may clear a protein linked to Alzheimer’s quickly and effectively.

Scientists have long suspected that clearing amyloid from the brains of people with dementia will slow down the disease, and so allow people with dementia to live independently and with milder symptoms for longer. However, we don’t yet know whether trontinemab will slow down symptoms getting worse. Until these results released, we cannot say whether this drug could be effective in the treatment of Alzheimer’s disease.

How does trontinemab work?

Trontinemab is made up of two components: gantenerumab and a Brainshuttle™.

Gantenerumab was developed to work in a very similar way to licensed drugs lecanemab and donanemab – by removing a protein called amyloid. Amyloid builds up in the brains of people with Alzheimer’s disease. Evidence suggests that it leads to brain cell damage. Over time, this results in the symptoms of Alzheimer’s getting worse.

In previous trials of just gantenerumab, gantenerumab failed to significantly slow down Alzheimer’s disease progression.

It’s thought that gantenerumab on its own didn’t slow down Alzheimer’s symptoms getting worse because it was slower at removing amyloid. As the results of the trial were based on measurements over 18 months, this may not have been long enough for it to have an effect.

Interestingly, newer data suggests that gantenerumab could still be beneficial to people living with Alzheimer’s over a longer period of time. In fact, we’ve seen this in small trials of people with directly inherited Alzheimer’s. More research in bigger groups is needed to confirm this.

So, what makes trontinemab different to gantenerumab or other similar drugs?

Trontinemab takes gantenerumab and adds a new, exciting piece of the puzzle – a brain shuttle.

This new technology helps the drug to get into the brain faster and spread to deeper parts of the brain.

What is a brain shuttle and how does it work?

Our brains have a special barrier that tightly controls what can enter or leave via our blood vessels. This is called the blood-brain barrier. Although it’s usually incredibly helpful to protect the brain, it does pose a major challenge when designing drugs to tackle diseases in the brain.

The brain shuttle binds to specific receptors in the blood-brain barrier, allowing it to pass into the brain much more easily. And because it does this in our smallest blood vessels, our capillaries, it is thought to be able to spread deep into the brain and clear more amyloid.

The brain shuttle technology means the drug could be given at lower doses and a higher amount will enter the brain to clear amyloid, compared to the treatment without the brain shuttle.

This technology is exciting, and it’s been a long journey to get to this point. Roche began testing trontinemab in the lab in 2012. So, it’s taken 13 years to get to this next phase. But, if these results are positive, this trial is the final hurdle before decisions are made about whether trontinemab will become available to people living with Alzheimer’s.

How effective is trontinemab?

At the moment, we only know some information about the biological effects of trontinemab in the brain. We don’t know how or if these changes will result in symptom progression slowing down.

The reason this drug is receiving so much attention is because of its speed. By 28 weeks, the drug had cleared amyloid in the brains of nine in every 10 volunteers.

This trial also included people with moderate Alzheimer’s. Everyone in this trial experienced some degree of amyloid clearance.

Phase 3 trials are generally the final stage of testing a drug goes through before the UK’s regulatory bodies will decide whether it can be made available in (see diagram).

 

The results of the Phase 3 trial will give us a much better picture of the drug, including how it works and who it works best in. These results aren’t due until 2028.

So, although we’re hopeful, we do need to wait to find out whether the drug slows down Alzheimer’s.

Can I take part in a trontinemab trial?

Phase three trials for trontinemab began recruiting in September 2025. If you meet the criteria for the studies, then you may be able to help researchers to find out how well this drug works.

There are two trials looking at how trontinemab works in people aged 50 to 90 with early symptomatic Alzheimer’s Disease (mild cognitive impairment or mild dementia due to Alzheimer’s disease).

A separate trial is looking at whether trontinemab can delay symptoms in people at higher risk of developing Alzheimer’s in the future. This trial, called ‘Preventron’ has begun recruiting in specific locations. Contact the Dementia Research Infoline for the most up-to-date information.

The best way to find out about taking part in dementia research studies, including trontinemab trials, is through a nationwide register called Join Dementia Research. This service is run by the NHS.

When you register, you provide some personal details about your health, age and contact details. These details are then used to match you to studies that you are suitable to take part in. Research studies are done online and face to face. Once registered, you can log into your account to take part in online studies, and you will be contacted by a researcher if you’re eligible to take part in a face-to-face study.

If you meet the criteria for the trontinemab trials, it will appear on your profile once you are registered. If not, there are plenty of other opportunities for everyone to take part in research, whether or not you have a diagnosis.

If you are interested in ‘Preventron’, signing up to Join Dementia Research will allow you to be automatically notified if the study is added to the service in the future and you may be eligible.

Signing up to Join Dementia Research is not a commitment to take part in any particular study, it just allows research studies to find willing volunteers. If you register today, you’ll receive an automatic email if you match to the study when it opens.

 

 

For more information about any of the trontinemab trials, you can contact our Dementia Research Infoline on 0300 111 5111 or email infoline@alzheimersresearchuk.org

Please note, Alzheimer’s Research UK cannot provide details of study locations outside the UK. Please contact your doctor or national dementia charity for more information.

How is trontinemab taken?

Trontinemab is delivered via an infusion into the arm. This involves spending several hours in a clinic every four weeks for the first seven doses. After that, clinic visits will be once every 12 weeks.

Is trontinemab safe?

The drug company have not yet published the full, unblinded safety data. So, it’s not yet clear how common side effects are.

When will trontinemab become available?

Trontinemab is still in clinical testing. Phase 3 trials began recruiting in late September 2025, and these typically take a few years to complete.

If successful, the drug could be submitted for regulatory approval in 2028 or later. Approval would depend on whether regulators decide that the trontinemab is safe and effective based on the trial results.

Will it be affordable and accessible through the NHS?

It’s too early to know. Whether the NHS will offer trontinemab will depend on:

• pricing decisions
• regulatory approval
• whether the NHS has the right systems in place to diagnose and monitor patients effectively.

Will trontinemab work on other types of dementia, such as vascular dementia or dementia with Lewy bodies?

Trontinemab targets amyloid, which scientists believe to play an important role in the development of Alzheimer’s. Amyloid is not thought to be as important in other types of dementia. So trontinemab hasn’t been tested as a treatment for other types. And it’s unlikely to work against other diseases that cause dementia.

Ongoing research is looking at what else brain shuttles could be used for. We believe it could hold promise for treatments for other forms of dementia.

Beyond trontinemab, there are nearly 140 drugs in clinical trials across the world investigating treatments for all types of dementia. At Alzheimer’s Research UK, we believe it is a question of when, not if, treatments for other types of dementia will become available.

How is trontinemab different to the dementia drugs we already have, like donepezil, memantine, galantamine and rivastigmine?

Current drugs for dementia are known as ‘symptomatic’ treatments. These allow our brain cells to communicate better and mask the damage caused by diseases like Alzheimer’s. But they do not target the actual disease itself.

These treatments can make a difference to somebody’s ability to manage their symptoms. But they can’t slow or stop the underlying damage getting worse.

By directly targeting amyloid, this new type of treatment aims to slow down the disease. Hopefully, it will allow people to live independently for longer.

Find out more about the difference between symptomatic treatments for dementia and new ‘disease-modifying’ treatments like lecanemab.

 

At Alzheimer’s Research UK, we won’t rest until we have found cures for the diseases that cause dementia. Although drugs like donanemab and lecanemab are promising, their effects are modest and they don’t stop the disease from progressing entirely. We’ll likely need to combine these drugs with others that target other underlying disease processes beyond amyloid, to make real progress in stopping dementia.

So we need to keep exploring other treatment avenues in order to find the next generation of effective treatments. Initiatives like our Drug Discovery Alliance, which brings together world-leading scientists from the Universities of Oxford and Cambridge, and University College London, are crucial to unlocking these other routes to treating Alzheimer’s and other types of dementia. You can hear about emerging treatments from some of the researchers themselves, in our Online Public Event here and by reading our blog.

 

 

If you have any questions about trontinemab, dementia, dementia research, or taking part in trials, you can contact the Dementia Research Infoline  on 0300 111 5 111 (9-5pm Monday to Friday) or infoline@alzheimersresearchuk.org