Are new Alzheimer’s drugs the revolution doctors have been waiting for?

Two new drugs, called ‘lecanemab’ and ‘donanemab’, are gaining significant attention as the former is capable of slowing the debilitating progression of Alzheimer’s disease.

But while their defenders see them as a breakthrough in medical research, critics see them as another disappointment after a series of costly failures.

“We’ve turned a corner” thanks to these treatments, said British biologist John Hardy, who has been studying Alzheimer’s since the 1990s. AFP.

Rob Howard, professor of geriatric psychiatry at University College London and a critic of the drugs, said: “I think the drugs have been used to give people with Alzheimer’s and their families false and unrealistic hope.”

These opposing statements summarize the entrenched positions on recently introduced drugs for Alzheimer’s disease, the most common form of dementia that affects millions of people around the world.

Lecanemab, sold under the name Leqembi, was developed by US pharmaceutical companies Biogen and Eisai. Donanemab, developed by pharmaceutical giant Eli Lilly, is sold as Kisunla.

The controversy has seen countries take different positions on whether or not to approve the drugs.

The United States gave the green light to lecanemab in 2023 and then to donanemab earlier this year. However, the European Union rejected lecanemab in July, a bad sign for donanemab’s likelihood of approval.

Last month, the UK took a middle ground, approving the use of lecanemab but not making it available to the state’s National Health Service.

What no one denies is that the two drugs are the most effective Alzheimer’s treatments ever, but their effectiveness is limited.

Both appear to reduce cognitive decline in patients at the onset of their disease by about 30%, which seems high but represents a relatively small difference over the year-and-a-half period the studies were conducted.

“The benefits are so tiny that they’re practically invisible to an individual patient,” Howard said.

Expensive

Critics say the drugs, which can sometimes cause brain swelling or bleeding, are not worth the risks and are too expensive.

At the prices charged by Biogen and Eisai in the US, lecanemab would cost €133 billion if given to all eligible patients in the EU, according to a 2023 study.

Meanwhile, proponents of the drugs, including many neurologists, believe they can give patients a few precious months of autonomy and that the drugs’ effectiveness could be multiplied if patients started taking them earlier in the disease’s progression.

This could soon be more practical, as research to diagnose Alzheimer’s more quickly has recently made significant strides.

Different national policies could also mean that poorer patients are left behind.

“We’re going to see rich people going to the U.S.” for drugs, Hardy said.

The debate can be traced in part to a seminal 1992 article by Hardy about how the disease actually works.

The article argues that clumps of protein called amyloid plaques – a constant in the brains of Alzheimer’s patients – are not just one element among others, but the main factor that causes the disease.

Over the decades, many drugs have been developed that target these amyloid plaques, all of which have failed — until lecanemab and donanemab.

Pressure from families

The skepticism from some quarters about the new drugs may be because the earlier ones were defended and even praised by some, despite their ineffectiveness.

Christian Guy-Coichard, head of the French organization Formindep which monitors medical conflicts of interest, accused Alzheimer’s groups, researchers and drug companies of being too close.

But Alzheimer France’s deputy director, Benoit Durand, said very little of its funding came from Biogen/Eisai or Eli Lilly, instead highlighting the pressure for new treatments from patients’ families.

They “don’t understand” the EU’s decision to reject a new innovative drug, Durant said AFP. He also feared that labs could lose interest in Alzheimer’s disease because of the failures.