Breakthrough in Alzheimer’s therapy? Drug slows mental decline

Alzheimer’s is the most common form of dementia. It is a currently incurable neurodegenerative disease that, according to calculations by the Alzheimer’s Disease International organization, affects approximately 55 million people worldwide. By 2050, there could be 139 million worldwide. The course of the disease is characterized by a slow but progressive decline in mental abilities.

Research into drugs for the treatment of Alzheimer’s is slow and characterized by many setbacks. It was not until mid-November that the drug gantenerumab from the pharmaceutical company Roche did not meet expectations. The drug was barely able to reduce the deposits in the brain that are characteristic of Alzheimer’s disease, the so-called beta-amyloid plaques. This key protein – along with tau protein – gradually accumulates in the brain, causing brain cells to die and the brain to shrink.

But now there seems to be a glimmer of hope – the antibody drug lecanemab can eliminate the beta-amyloid deposits, as the results of a clinical study published in the “New England Journal of Medicine” give cause for hope. The phase III trial was conducted over 18 months in 1,795 patients with early onset dementia at 235 centers in North America, Europe and Asia. Half of the patients received the drug every two weeks, while the other half received a placebo.

The course of the disease was monitored at regular intervals; for example, the patients’ memory ability, orientation ability and problem-solving ability were examined. The positive result: Cognitive decline in lecanemab-treated patients slowed by an average of 27 percent. These patients outperformed those in the placebo group at 18 months. But their illness had also gotten worse.

Lecanemab was developed by the Japanese pharmaceutical company Eisai and the American company Biogen. The drug cannot cure or stop Alzheimer’s disease, but it may slow mental decline, said German Alzheimer’s researcher Frank Jessen of the German Center for Neurodegenerative Diseases (DZNE), who was not involved in the study, the “Stern “. Jessen speaks of a “historic milestone in Alzheimer’s research”. Other observers speak of a new era in Alzheimer’s therapy.

The effectiveness of the drug was already known at the end of September; now the detailed results of the study have been presented at the Alzheimer’s Conference Clinical Trial on Alzheimer’s Disease (CTAD) in San Francisco. However, they also show the incidence of the side effects, some of which were serious and also occurred significantly more often than in the control group of patients who had received a placebo.

It was shown that 17.3 percent of patients treated with lecanemab suffered from cerebral haemorrhages – compared to 9 percent in the placebo group. The difference was even greater for cerebral edema: here it was 12.6 percent of patients who received the drug compared to 1.7 percent of placebo recipients.

Questions had been raised about the drug’s safety after some scientists linked two study deaths to the antibody drug. However, the all-cause mortality rate was almost the same in both patient groups (0.7% in the patients who received lecanemab; 0.8% in the placebo group). According to the study, a total of 13 people died during the testing period, including 6 who received the drug and 7 in the placebo group. None of the deaths were attributed to lecanemab by the study authors.

“It is the first drug that offers a real treatment option for people with Alzheimer’s disease,” Bart De Strooper, director of the British Institute for Dementia Research, told The Guardian. “While the clinical benefits appear somewhat limited, they can be expected to become more apparent as the drug is administered over a longer period of time,” he added.

Linda Thienpont, Head of Science at the Alzheimer’s Research Initiative, comments on the results:

Since lecanemab only targets deposits of the beta-amyloid protein in the brain in the early stages of Alzheimer’s disease, this could limit its use – Alzheimer’s disease is often diagnosed late. In addition, the drug is expensive – between £10,000 and £30,000 a year per patient (equivalent to between £11,400 and £34,200), as the Guardian writes. And this with a still fairly modest effect, at least over 18 months.

Nevertheless, lecanemab is already being tested in the US in an accelerated approval process. An application for market approval in Europe and Japan is also scheduled for the end of March next year. (i.e)