Scientists on Wednesday welcomed detailed results of a clinical study on a new drug confirming its effectiveness in slowing cognitive decline in patients with neurodegenerative Alzheimer’s disease, but also noted its sometimes severe adverse effects.
The complete results of this advanced clinical study (phase III) carried out in almost 1,800 people followed up for 18 months confirmed a 27% reduction in cognitive impairment in patients treated with lecanemab, a drug developed by the Japanese pharmaceutical group Eisai and the American Biogen.
This “statistically significant” proportion according to the two groups had already been announced at the end of September.
Sometimes serious side effects
But the full study, published Wednesday in the New England Journal of Medicine, also specifies the incidence rates of lecanemab side effects, which are sometimes severe and markedly more frequent than in the placebo group of patients.
Thus, 17.3% of the patients treated with lecanemab suffered brain haemorrhages, compared to 9% in the placebo group.
And 12.6% of people who received this experimental drug developed cerebral edema, compared to just 1.7% in the placebo group.
However, the overall mortality rate is about the same in the two groups of patients in the study (0.7% in people treated with lecanemab, 0.8% in those who received placebo).
“A Royal Choice”
“This is the first drug to offer a real treatment option for people with Alzheimer’s,” said Bart De Strooper, director of the UK Dementia Research Institute.
“Although the clinical benefits appear somewhat limited, they can be expected to become more apparent if the drug is administered over a longer period,” the professor said.
In Alzheimer’s disease, two key proteins, tau and another called beta-amyloid, gradually accumulate abnormally in the brain, causing brain cell death and brain shrinkage.
This causes, among other things, memory loss and an increasing inability to perform daily tasks. This disease is one of the main public health problems, affecting tens of millions of people around the world.
Target protein deposits
Lecanemab targets beta-amyloid protein deposits, but only in the early stages of Alzheimer’s disease, which could limit its use because this disease is often diagnosed late.
Another anti-Alzheimer treatment from Biogen and Eisai, called Aduhelm (adacanumab) and also targeting amyloid plaques, had already raised high hopes in 2021 as the first drug approved in the United States against the disease since 2003.
But Aduhelm has also caused controversy, since the US drug agency FDA has opposed the opinion of a committee of experts, which had judged that the treatment had not sufficiently demonstrated its efficacy during clinical trials. The FDA later restricted its use.
Countless pharmaceutical companies, such as recently the Swiss giant Roche, have so far fallen apart with Alzheimer’s disease, which remains incurable for the time being and whose precise causes and mechanisms are still largely uncertain.
The new treatment from Eisai and Biogen is also not curative and “there is no accepted definition of clinically significant effects on the cognitive test” that the study authors used, said Tara Spires-Jones, associate director of the Center for Science Discovery. University brain. from Edinburgh (Scotland).
“It is not yet certain that the modest reduction (in the rate of cognitive decline, editor’s note) will make a big difference” for patients, and “longer trials will be needed to ensure that the benefits of this treatment outweigh the risks,” the neuroscientist added.
Source: BFM TV
