Dementia drug hailed for slowing down Alzheimer’s by up to a THIRD may be unsafe for 9 out of 10 patients

One of the first Alzheimer’s drugs that could slow the progression of the disease should not be given to the majority of patients due to safety concerns, a study suggests.

Research appears to show that the drug, lecanemab, can slow degenerative brain disease by a third. And last month, U.S. health regulators approved the bimonthly injection for patients with mild cognitive impairment or mild dementia — meaning early-stage Alzheimer’s disease.

The NHS spending watchdog will begin reviewing the drug for use in the UK next month, hoping it can help the UK’s one million Alzheimer’s patients.

But research warns there is no data showing the drug is safe for nine out of 10 patients with early-stage Alzheimer’s disease. This is because the drug has only been tested on patients who are otherwise healthy.

Patients hoping to participate in the lecanemab trial, conducted by the Japanese drug company Eisai, were unable to participate if they had conditions such as obesity, diabetes, heart problems or a history of cancer.

Despite participants having a clean bill of health, there was a high rate of side effects. According to data published by Eisai, about one in ten patients taking lecanemab had life-threatening brain swelling and one in six had cerebral hemorrhages. Three members of the 1,800-participant trial died due to side effects related to the drug.

Researchers from the Mayo Clinic in Minnesota, USA, looked at the health records of 237 older adults who suffered from mild cognitive impairment or mild dementia and found that 92 percent of them had an underlying health problem that would have excluded them from the lecanemab trial.

Dr. Maria Vassilaki, an epidemiologist at the Mayo Clinic and author of the study, said more research was needed to explore the safety and effectiveness of lecanemab before it could be offered to “less healthy populations.”