The first drugs to slow down Alzheimer’s – but what does it mean for patients?
Research into Alzheimer’s and the search for a successful treatment is currently in an intense phase. For the first time, an approved treatment is available that is effective against the disease itself and not just focused on alleviating the symptoms.
In July, Lecanemab, developed by Sweden’s Bioarctic and Japan’s Eisai, received full market approval from the US Food and Drug Administration (FDA). Eli Lilly’s drug candidate, Donanemab, is expected to follow suit later this autumn.
A possible authorisation in Europe is currently subject to a review being carried out by the European Medicines Agency (EMA).
“Hopefully, this drug will be available in about a year. I am quite convinced that it will be approved in Europe and also in Sweden. I find it hard to imagine the arguments for not approving it,” says Kaj Blennow, Professor of Clinical Neurochemistry at the University of Gothenburg and one of Sweden’s leading researchers in the field.
Lecanemab and Donanemab both focus on removing amyloid beta plaques from the brain, and both are intended for use in the early stages of the disease. They do not provide a cure but a moderate slowdown of the disease, which gives hope for prolonging the time with functional brain functions.
As an example, a follow-up study of Lecanemab after 18 months showed a 27% reduction in deterioration in those receiving treatment compared with the placebo group. Comparable results have been presented for Donanemab.
So, how significant an impact will the new treatments have for patients?
“I think we should be optimistic but also realise that this is currently not a treatment that can be used widely and at all stages,” says Agneta Nordberg, Professor of Clinical Neuroscience at the Karolinska Institute and Senior Consultant at the Memory Clinic at Karolinska University Hospital.
Both drugs aim to treat patients with mild symptoms of the disease. But how early can we diagnose Alzheimer’s today? Early enough for the treatments to fulfil their purpose, says Kaj Blennow.
Today, cerebrospinal fluid (CSF) tests are often used in combination with memory tests to make a diagnosis. Spinal fluid tests can measure the specific pathologies that characterise the disease. They allow the measurement of amyloid beta plaques and the nerve cell protein tau and its phosphorylated form, which increases in the spinal fluid when cells are damaged and break down. The test is usually performed after a referral to a specialist clinic.
“The test is also performed in some health centres, such as in the small town of Kalix. With a bit of training on how to perform a spinal fluid test, it’s not a big problem,” says Kaj Blennow.
In other countries, for example, the United States, PET camera scans are often used instead of spinal fluid tests. A PET camera can be used to detect amyloid beta plaques in the brain. However, in Sweden, the method is not used to the same extent as the technology is expensive and capacity is limited.
Recently, the development of blood tests to measure the same proteins as spinal fluid tests has raised high hopes in the diagnostic field. The blood tests are less invasive and could be performed directly in a health centre.
“Based on the current situation, I don’t think we will exclusively use blood tests, but I think they will be beneficial in diagnosing Alzheimer’s,” says Kaj Blennow.
Blood tests developed to measure phosphorylated tau can provide a diagnosis with about 85% certainty, says Kaj Blennow.
“If we were to rely on blood tests alone, we would have a 15% misdiagnosis,” he says.
This is why he believes that we will use blood tests both to find high-risk patients and rule out Alzheimer’s disease in the future. This would leave only a small group, around 25%, who would still need to undergo a spinal fluid test or perhaps a PET camera examination at a specialist clinic, says Kaj Blennow.
Although diagnostics are developing at a rapid pace and the disease can be detected at an early stage, not all patients are suitable for the treatment. For example, it is not suitable for people on blood-thinning drugs.
There is also a risk of side effects, such as temporary brain swelling, when the amyloid plaque disappears. Therefore, in addition to the fortnightly infusions of Lecanemab, patients should also undergo follow-up MRI scans.
“Brain swelling appears as white spots on MRI images,” says Agneta Nordberg.
“Most cases are symptom-free, but 2-3% of patients experience serious problems. We need to have teams in hospitals available to interpret this, which adds to the difficulties of using this treatment on a large scale,” she says.
The available resources in the healthcare system where you live are an important factor. According to Agneta Nordberg, making the treatment available in general practice would impose completely new demands on the healthcare system and would require significantly greater resources.
“The healthcare system is currently under great strain, and I’m not sure we are organisationally prepared for this. Let’s assume that a clinic has 80-100 patients who receive this kind of infusion and come in every two weeks – where would the staff come from to deal with this?”
Besides the fact that a widely used treatment would put pressure on the healthcare system and its resources, the cost of the drug itself is also significant.
In the US, the list price for Lecanemab has been set at USD 26,500, corresponding to approximately SEK 290,000, per year of therapy, which means, in theory, that if all approximately 100,000 Swedes who have Alzheimer’s were given the treatment, the costs would correspond to well over 80% of Sweden’s total pharmaceutical costs today.
It is reasonable to assume that a selection must be made, but the question is on which criteria.
According to Agneta Nordberg, from a Swedish perspective, it is most likely that the treatment will first start at academic memory clinics and that the selection of patients, and the organisation of the treatment will be subject to consultation at treatment conferences at memory clinics. She emphasises that it is also important for patients and relatives to be carefully informed about both the benefits and risks of the treatment and for patients to make a personal decision.
According to Agneta Nordberg, we still have to learn and accept that memory disorders that affect people in their 80s and 90s are different from those that appear at a younger age. Older patients may also have a co-morbidity that prevents treatment with this type of drug.
“In my opinion, the greatest progress would be if we could treat those affected at a younger age, that is, between 50 and 70. The disease is often aggressive in this age group, and the deterioration is often very fast, while the symptoms are often detected early,” she says.
Artikeln är en del av vårt tema om News in English.