Doctors are hailing a “new era” in medicine after a study showed for the first time that a drug could slow the debilitating symptoms of Alzheimer’s disease.
The results of the clinical trial also showed that the drug lecanemab cleared the brains of patients of clumps of a protein called amyloid, which is thought to be the main cause of the most common form of dementia.
The data, presented at a conference in San Francisco, sparked optimism among scientists, many of whom have spent decades trying to understand what causes the disease and find a cure.
Rob Howard, professor of geriatric psychiatry at University College London, said the results were “very good and hopeful” – adding: “We finally have the answer to one of the most horrific and most feared diseases and years of research and investment. Some understanding finally pays off.
“It feels momentous and historic. It will encourage real optimism that dementia can be defeated and maybe even cured one day.”
The drug’s maker released top-line results at a news conference earlier in the fall, but many doctors didn’t celebrate until the full results were released at the Alzheimer’s Disease Clinical Trials Conference.
They showed that lecanemab slowed the rate of memory and intelligence decline by 27 percent in patients with mild Alzheimer’s disease.
“The doctor is optimistic”
Crucially, the drug removed so much amyloid that patients did not have enough evidence of Alzheimer’s disease on brain scans to actually qualify for the trial.
The study strongly suggests that the drug will only begin to have clinical effects when amyloid levels in the brain are reduced to low levels.
The results after 12 months of treatment showed that it was not effective – but after 18 months, the effect was remarkable.
Doctors are optimistic that continued treatment will lead to better outcomes.
Professor Nick Fox, Director of the Center for Dementia Research at UCL, said: “It confirms a new era of disease transformation in Alzheimer’s disease, arrived after more than 20 years of hard work by many, many, many people Yes. Disappointments along the way.”
Lecanemab is not a cure. But even slowing the progression of Alzheimer’s disease would be a game-changer, delaying the need for specialist care and giving people more time to spend with their families.
However, this drug has side effects.
One in eight patients treated with lecanemab experienced brain swelling and other changes that may be due to the removal of amyloid. But most had only evidence of a problem with brain scans. Less than a third had actual symptoms such as headaches or confusion.
Some patients developed brain bleeds, although those who received the treatment did not die any more than those who received the counterfeit drug.
Nonetheless, it highlights the need for careful monitoring of those receiving treatment.
Prof Fox said: “Any risk is obviously important, but I believe many of my patients would be very willing to take such a risk.
‘A huge challenge for the NHS’
Doctors have warned that lecanemab will be a huge challenge for the NHS, not least because the drug is given by intravenous infusion every fortnight.
Currently, most Alzheimer’s patients are diagnosed when they have moderate symptoms — too late for treatment with lecanemab. Only 1% of people are diagnosed with a brain scan or lumbar puncture (spinal fluid biopsy).
Susan Kohlhaas, director of research at Alzheimer’s Research UK, said: “It’s safe to say the NHS is not ready for this new era of dementia care.
“We estimate that unless there is a dramatic change in the way people access specialized diagnostic tests for Alzheimer’s disease, only 2 percent of people who qualify for drugs like lecanemab will have access to these tests.”
So far, there are only drugs that treat the symptoms and not the underlying cause. But if lecanemab is licensed on the NHS, delaying treatment will lead to brain cell death and disease progression.
Professor John Hardy, from the UK’s Dementia Research Institute in London, said the drug “has been around for a long time”.
He added: “I truly believe it represents the beginning of the end.
“The first step is the hardest, we now know exactly what we need to do to develop effective medicines. It’s exciting to think that future work will build on this and we will soon have life-changing treatments to deal with this disease.”