The US Food and Drug Administration (FDA) on Thursday granted standard approval to the first drug shown to be effective in slowing Alzheimer’s symptoms, Leqembi, paving the way so that medical insurance companies cover the high cost and its use can be generalized.

It’s the first time in two decades that an Alzheimer’s drug has received full approval from the FDA, meaning the agency’s experts believe there is strong evidence of potential benefits for affected by this degenerative disease, which has not happened with other studied drugs.

Trial data show that the treatment cannot repair cognitive damage, reverse the course of the disease or prevent it from getting worse, but it does slow progression by 27% in people in the early stages.

These benefits are what have led the FDA to give the green light to the drug lecanemab – marketed as Leqembi -, despite the fact that some cases of serious adverse effects were recorded among those who tried the medicine. Because of this, the FDA has added the most severe safety warning (black box) to the drug’s label, to indicate that, in rare cases, the drug may cause “serious and life-threatening events,” and that there there have been cases of cerebral haemorrhage, “some of which have been fatal”.

This label explains the need to monitor patients to avoid potentially dangerous brain inflammation and bleeding associated with amyloid-reducing antibodies. The risk is greater, according to the experts, in patients with two copies of a gene, APOE4, a condition present in around 15% of people with Alzheimer’s. That’s why the FDA’s black box warning recommends that all patients undergo genetic testing to assess their risk for the drug.

On the other hand, the regulator recommends not prescribing this treatment to patients who use anticoagulant medication, because it increases the risk of suffering cerebral haemorrhages.

In the trial, almost 13% of patients who received Leqembi experienced brain inflammation, which was mostly mild or moderate, compared to only 2% of patients who received placebo. About 17% of those who took the drug experienced brain bleeds, compared to 9% of those who received a placebo.

Leqembi, developed by the Japanese pharmaceutical company Eisai – now associated with Biogen for commercialization and marketing – had already received “accelerated” approval from the FDA in January for its ability to eliminate amyloid, but the plan to The US government’s Medicare for over 65s had restricted coverage to patients in a clinical trial.

The standard approval reached on Thursday means that Leqembi will now be covered by health insurance, although the Medicare agency is tying the reimbursement of the cost of the treatment (it covers 80%) to the fact that the patient is registered in a of data from health agencies, to get more information about the benefits or harms of this drug.

Lequembi, which is administered intravenously, has a retail price in the United States of $26,500 a year (about 24,400 euros).