Dementia drug linked to lethal bleeds will ‘get the green light in the US swaying UK to do same’

Leading scientists have hinted that US regulators are ready to give the green light to a first-of-its-kind dementia jab – despite claims it could cause deadly bleeding in the brain.

A world-renowned dementia expert and former adviser to the US drug watchdog the Food and Drug Administration (FDA), who asked to remain anonymous, said he feared the decision could prompt UK health chiefs to do the same.

Approval of the drug – lecanemab – will “cost lives not only in the US, but also in the UK and other countries,” he warned.

The drug is injected twice a month and hailed as ‘the beginning of the end for Alzheimer’s disease’ when first study results were revealed in September showing it could slow the disease by a third.

But security concerns have since emerged, leading many experts to say it shouldn’t be rolled out until more is known. In a series of exclusive reports, The Mail on Sunday revealed that one in ten people taking the drug suffer from life-threatening brain swelling and one in six develops a brain hemorrhage, according to data published by the pharmaceutical company behind the drug.

The MoS last month reported the case of a 79-year-old Florida woman who died suddenly after taking three doses of lecanemab as part of a medical trial. Experts who investigated her death concluded that the cause was a fatal seizure induced by the drug.

Despite this, lecanemab is expected to be approved by US health chiefs next month after lobbying from dementia campaigners.

“There’s so much pressure on the authorities to deliver this drug, I don’t think they can’t approve lecanemab,” the former FDA adviser said. “It’s almost certain to get the green light in June.”

The calls have been led by the leading US dementia charity, the Alzheimer’s Association, which has been accused of a conflict of interest and bias — which it strongly denies.

Last year it was reported to have received more than £220,000 from pharmaceutical company Biogen, which helped develop lecanemab.

The drug works by attacking a toxic protein in the brain called amyloid. Amyloid proteins circulate freely in the blood, but when they clump together in the brain and form plaques, it causes the brain damage that causes dementia symptoms.

Experts believe that the chemical reaction that occurs in the brain when lecanemab removes plaque can inflame blood vessels, increasing the risk of bleeding.

The FDA has already accelerated the drug through the regulatory approval process due to the urgent need for effective dementia drugs. It has also published guidelines for prescribing the drug, so doctors are ready to offer the shots as soon as it gets the go-ahead.

However, experts say that the committee should carefully consider the side effects in question.

It was initially believed that patients also taking blood thinners given to people with heart disease had the greatest risk of cerebral hemorrhage. But scientists at Vanderbilt University in Nashville, Tennessee, suggest that many more patients are at risk.

It appears that all three patients who died from possible lecanemab side effects during the study had a condition called cerebral amyloid angiopathy – a buildup of amyloid plaque on the walls of blood vessels that increases the risk of dangerous bleeding.

Studies suggest that about half of all Alzheimer’s patients have cerebral amyloid angiopathy. There may also be a risk for those taking certain types of antidepressants, which are commonly prescribed for people with Alzheimer’s disease, experts say.

The drug is injected twice a month and hailed as ‘the beginning of the end for Alzheimer’s disease’ when early research results revealed in September showed it could slow the disease by a third (stock photo)

However, others say the most disturbing fact about lecanemab is that doctors will have a hard time predicting who will experience serious side effects, as cerebral amyloid angiopathy is very difficult to spot.

“Blood thinners and some antidepressants can increase the risk of cerebral haemorrhage, but what worries me most is that patients who don’t take any of these drugs can also experience life-threatening side effects,” said Robert Howard, a professor of age-related psychiatry at University College London’s Institute of Mental Health.

“Once the FDA approves lecanemab, it will be up to UK medical regulators to make their decision. I trust that they will make the right decision.’

The pharmaceutical company that makes lecanemab, Eisai, declined to comment.

In an earlier statement to The Mail on Sunday, a spokesperson for the Alzheimer’s Association said: ‘We make decisions based on science and the needs of our constituents.

“No contribution from any organization will influence the decision-making of the Alzheimer’s Association.”