Think twice before buying a new ‘miracle cure’ for dementia, experts warn, after reports emerged that two people died in the US last year from suspected side effects

Patients have been warned against privately purchasing a new “miracle drug” for Alzheimer’s disease after reports emerged that two people in the United States died from suspected side effects last year.

The drug Lecanemab has been shown to slow the progression of the degenerative brain disease by about six months.

Last week, the NHS spending regulator rejected the infusion drug because the benefits were “too small to justify the cost”.

The National Institute for Health and Social Care Excellence (NICE) added that there were concerns that patients would need to be monitored for “serious side effects”.

Last week, the infusion drug was rejected by the NHS spending regulator because the benefits were “too small to justify the cost” (archive photo).

According to experts, around 3,000 patients have started taking the drug since it was approved by the US health authorities in July 2023 (archive photo)

About one in ten study participants suffered swelling in the brain and one in six had small brain hemorrhages, which in rare cases led to life-threatening symptoms. Three patients in the study involving 1,800 participants died from suspected side effects.

However, lecanemab, which costs an estimated £20,000 a year, will now be available privately in the UK. Experts predict that thousands of desperate patients will turn to private providers to get lecanemab, but warn that doing so could put their health at risk.

Earlier this month, at the Alzheimer's Association's international conference in Philadelphia, it was reported that two patients in the United States had died from suspected side effects after taking lecanemab.

According to experts, about 3,000 patients have started taking the drug since the U.S. health authorities approved it in July 2023.

One death was confirmed by Dr. Lawrence Honig, a neurologist at Columbia University in New York. A second death was reported by the science website Alzforum. None of the patients have been identified, but according to Dr. Honig, one carried a gene – called APOE4 – that research has shown puts patients at a higher risk of brain bleeding. Around 15 percent of Alzheimer's patients carry this gene.

Lecanemab, which costs an estimated £20,000 a year, will now be available privately in the UK (archive photo)

Lecanemab and donanemab work by attacking a toxic protein in the brain called amyloid, which is linked to dementia symptoms

“Anyone who can afford to get this drug privately needs to carefully weigh up the benefits and risks and decide whether it is worth taking lecanemab,” says Robert Howard, professor of geriatric psychiatry at the Institute of Mental Health at University College London.

“People think it will buy them more time, but the data shows little benefit. At the same time, the risks are very real.”

One million people in the UK have Alzheimer's disease and there are currently no treatments available from the UK National Health Service that can slow the disease. Lecanemab – and a similar drug called donanemab – are the first treatments shown in trials to be effective against the loss of brain function caused by Alzheimer's.

The drugs are given as an infusion every two weeks. Lecanemab and donanemab work by attacking a toxic protein in the brain called amyloid, which is linked to dementia symptoms.

When trial results for both drugs were announced last year, experts said the findings marked the “beginning of the end” of Alzheimer's disease. But the treatments have been dogged by controversy since then. The MoS was the first to report the death of 79-year-old Lecanemab trial participant Genevieve Lane from Florida, who suffered a fatal seizure in 2022, just a week after her third dose. An autopsy found Lecanemab likely triggered the ruptured blood vessel in Genevieve's brain that led to her death. Two other deaths in the trial were linked to side effects. Earlier this year, this newspaper also revealed that senior figures in the NHS had raised concerns that the rollout of the treatments could cost taxpayers £1 billion a year and put the lives of Alzheimer's patients at risk.

Lecanemab, sold under the brand name Leqembi, is a monoclonal antibody used to treat Alzheimer's disease.

One million people in the UK suffer from Alzheimer's and there are currently no NHS treatments that can slow the disease.

A report from the UK National Health Service said the drugs were only effective when given at the earliest stage of the disease and suggested that monitoring patients for possible side effects could be a significant drain on resources.

When NICE decided against introducing lecanemab on the NHS last week, it cited these concerns. Dr Samantha Roberts, head of NICE, said: “This is intensive treatment for patients requiring a two-week hospital visit, with skilled staff required to monitor them for signs of serious side effects. Added to this is the cost of purchasing the drug.”

A spokesman for Eisai, the manufacturer of lecanemab, said: “The second death described in the media was confirmed as a rumour by the news agency that first reported it.”

“Eisai is unable to respond to rumors. Eisai continues to fulfill its obligations to monitor and report adverse events in accordance with global regulatory requirements.”