CTAD 2025: Six highlights from the latest clinical trials in Alzheimer’s disease

At the San Diego Conference, leading dementia scientists from around the globe came together to share the latest advances in clinical trials.

For more than 15 years, the annual Clinical Trials in Alzheimer’s Disease (CTAD) conference has become a launchpad for the latest news on advances in diagnosis and treatments. In the last few years, the momentum has been growing as we witnessed the arrival of treatments that can slow the progression of Alzheimer’s disease.  

These first‑generation drugs are a welcome step, but with modest benefits and they can come with serious side effects, they are not a cure. Today, the challenge is clear, we must keep up the pace and accelerate the search for new treatments. I was eager to dive into this year’s program and discover which promising therapies are moving us forward towards a cure.

Here are my top highlights from this year’s conference.

Are injections the future of anti-amyloid Alzheimer’s treatments like lecanemab?

Right now, Alzheimer’s drugs that slow down the disease require people to visit a clinic every couple of weeks for an intravenous (IV) infusion. For families and people living with Alzheimer’s, that can mean frequent trips to the hospital and long appointments. For healthcare professionals, it means dedicated infusion suites, staff time and costs of providing the treatment and intensive monitoring for side effects.

The high cost of delivering the drugs compared to the drug’s benefits were the reason that the treatments are currently not available on the NHS.

Eisai shared results showing that when lecanemab is given as an injection under the skin, the beneficial effect is equivalent to the currently approved IV infusions. If lecanemab can be given through an automated injection at home, this could potentially reduce the costs of delivering the drug and the need for hospital visits.

There’s still more to do, as researchers need to tackle side effects like brain swelling and bleeding. Regulators will also still need to approve this new way of delivering lecanemab before it can become available. But these findings hint at a future where injections replace lengthy infusions, making treatment simpler and more accessible.

The latest Alzheimer’s treatments in development

Early clinical trials are where ideas turn into hope, and every positive result could spark the next big step forwards.

Currently, 138 drugs are being tested in 182 trials globally. At CTAD we heard encouraging results from several of these on-going trials. From etalanetag, which may lower levels of Alzheimer’s proteins in the brain after three months in inherited types of Alzheimer’s, to the latest results from blarcamesine. Blarcamesine helps boost the brain’s waste disposal system and early results suggest it may slow memory and thinking problems in people with mild cognitive impairment. Prof John-Paul Taylor also presented some interesting data on a trial drug for dementia with Lewy bodies, called neflamapimod, which may reduce inflammation in the brain.

We need to wait for the full trials and complete data before drawing conclusions, but it’s hard not to feel positive. By broadening the pipeline of drugs, we’re taking the next steps towards a future where Alzheimer’s is tackled with a wide range of treatments working on different targets.

Trontinemab: utilising the Brainshuttle™ to improve a potential Alzheimer’s drug

Back in 2022, researchers showed that gantenerumab did not slow memory and thinking problems in people with early Alzheimer’s in late stage clinical trials. Gantenerumab works by removing amyloid from the brain. Today, when combined with the brainshuttle™ to help it get into the brain, the drug has recaptured everyone’s attention with its promising early results under its new name trontinemab.

Trontinemab is manufactured by Roche and uses ‘brain shuttle’ technology enabling gantenerumab to be carried across the brain’s protective barrier more effectively. This means the trontinemab could be given at lower doses potentially resulting in fewer side effects than current treatments that don’t use the brain shuttle.

While the full results won’t arrive until 2028, the early findings are striking. At a conference in July, we heard that over nine in ten people taking trontinemab saw their amyloid levels fall, with fewer side effects than the current anti-amyloid treatments. Although we still need to wait to see if this translates to a slowing down in the decline of memory and thinking, I was excited to hear that recruitment for the on-going clinicals is now faster thanks to dementia blood tests that quickly identify who can take part.

We also saw that a new trial is starting to explore whether trontinemab could prevent Alzheimer’s. Scientists will investigate this in people who are not displaying symptoms of dementia but have high levels of amyloid in their brain. If successful, it could pave the way for treatments that can stop the disease sooner as doctors can intervene at its earliest stages.

Could technology improving access to the brain unlock better Alzheimer’s therapies?

At the conference, the pharmaceutical company, Lilly presented data about their focus to investigate donanemab with a shuttle to improve access to the brain. The group are hoping that using this technology could still remove amyloid from the brain but with reduced side effects like swelling and bleeding in the brain.

Continued success using different shuttle technologies could set the stage for a new era of treatment if they can help to make potential therapies safer, easier to administer and especially if they could carry multiple types of therapies at the same time.

Diabetes drug does not slow down Alzheimer’s

The week before the conference we learned that diabetes drug semaglutide failed to slow down the decline in memory and thinking in people with early Alzheimer’s disease. Previous research has shown that people taking GLP-1 medicines for other conditions like type 2 diabetes appeared to have a lower risk of developing dementia.

Full results presented at the conference did show that semaglutide could slightly reduce levels of Alzheimer’s related proteins in spinal fluid.

It could be that the benefits of diabetes drugs on lowering the risk of dementia happens in the earliest stages of Alzheimer’s disease, or in people who have not been diagnosed but are at risk.

While the results may feel disappointing, every result – be it positive or negative – gives us a better understanding of what treatments to pursue. It also shows when it comes to treating Alzheimer’s, no single approach is likely to be enough. People with Alzheimer’s urgently need better options, and this setback reinforces the need to invest in the science.

Shingles vaccine linked to slower dementia progression 

Earlier this year, a study using Welsh health data suggested the Zostravax (shingles) vaccine could help with preventing or delaying the onset of dementia.

Although new research presented showed the vaccine had a protective effect in both men and women, protective effects were greater in women.

The benefits weren’t limited to dementia alone, the vaccine also appeared to reduce mild cognitive impairment and dementia-related deaths, suggesting it could help at different stages of the disease.

While these results are promising, clinical trials are needed to confirm the connection and understand how the vaccine might protect the brain.

Final thoughts

It is great to see how fast the field continues to progress. And although the results of some of these trials are just getting started, I am looking to the future of Alzheimer’s with more optimism every year. With continued research funding, we can get closer to a cure for dementia.