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  • Health The therapeutic revolution of Alzheimer's comes hand in hand with new biological drugs

Acting effectively on the early stages of Alzheimer's disease is one of the desires of the scientific community. Numerous laboratories and companies around the world are working in this direction, a fact that has been giving very hopeful news in recent years and months.

The latest development is related to the monoclonal antibody in the trial donanemab, a molecule that targets the amyloid protein, which has significantly slowed cognitive and functional decline in people with early-stage Alzheimer's disease, according to data from a phase III study published in JAMA.

Last May, the company Eli Lilly, owner of the molecule, announced the first positive results of the international randomized trial – the Trailblazer-ALZ2 – which is now published in the aforementioned scientific journal.

The study, conducted on 1,736 people from eight countries and followed up for 18 months, indicates that, in some cases, donanemab slowed the clinical progression of the disease.

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Neurology.

Keys to understanding why brains 'shrink' with new Alzheimer's drugs

  • Writing: PILAR PÉREZ Madrid

Keys to understanding why brains 'shrink' with new Alzheimer's drugs

In fact, among participants with early symptomatic Alzheimer's disease and the presence of amyloid and tau proteins, donanemab significantly reduced clinical progression at 76 weeks in those with low/medium tau protein presence, as well as in those with low/medium and high tau presence.

'Cleansing' amyloid

One of the key points of this work was to discern the ability of the monoclonal antibody donanemab to 'clear' amyloid plaque from the brain, which could provide a clinical benefit in early symptomatic Alzheimer's. This fact has been observed over time in the cases mentioned above.

The development of this new pharmacological therapy is a new breath of hope and reinforcement to the early approach to this neurodegeneration whose activity would be added to that of lecanemab, approved last January by the FDA under the name of Leqembi and developed by Biogen and Eisai, and awaiting approval in Europe.

Liz Coulthard, from the Department of Dementia Neurology at the University of Bristol, said: The results of this robust and innovative trial are encouraging and mean that in one to two years we will be able to offer patients a range of treatments that slow the progression of Alzheimer's disease.

Identify and adapt

"Some patients did not worsen significantly during the trial and, on average, disease progression slowed between 4.4 and 7.5 months over 18 months. The drug appears to have a significant benefit, at least, for some patients."

"How we can tailor treatment to the patients who will benefit the most – those with evidence of amyloid without very high levels of tau – and how we can limit the dose of medication. This is very important in clinical practice, especially because there are side effects and the costs can be significant."

"The results add new evidence that immune therapies that successfully clear amyloid plaques are associated with a modest slowing of Alzheimer's disease progression. The study is well conducted and stands out for additional evidence that therapy in the earliest stages of the disease – when there are still low levels of tau protein accumulation in the brain – brings the greatest benefits, Ivan Koychev, principal clinical researcher and neuropsychiatrist at the Dementia Platform UK and the University of Oxford, told SMC UK.

In his opinion, the effects in early stages of the disease raise the question of "whether these therapies should be given to people who have signs of Alzheimer's disease in the brain but do not yet have symptoms."

The side effects of these drugs remain a concern: "A significant proportion of patients developed a form of cerebral edema. On a positive note, this side effect resolved without causing symptoms in most patients."

Thus, he considers that the next stage is to "find out what the long-term results are for those who have followed the therapy: we do not yet know when patients would stop treatment in the real world."

  • Alzheimer
  • Neurology
  • Pharmacology

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