The approval of a new drug to treat Alzheimer’s disease is controversial.

The U.S. Food and Drug Administration gave full approval to the drug lecanemab (Leqembi) Thursday to treat adults with Alzheimer’s disease.

In January, Public Citizen, a consumer advocacy organization, urged the agency not to approve the drug. In a letter to the FDA, it said that lecanemab investigators have concluded that longer trials are needed to determine the effectiveness and safety of lecanemab in early Alzheimer’s disease, and that three deaths thought to be related to the drug have now occurred in lecanemab subjects.

In June, Public Citizen urged the agency not to grant full approval because the evidence for the drug’s benefits doesn’t outweigh its significant risks..

The FDA’s decision to grant full approval for lecanemab to treat adult patients with Alzheimer’s disease is misguided and very disappointing, said Robert Steinbrook, M.D., director of Public Citizen’s Health Research Group.

“The evidence for the drug’s clinical benefits does not outweigh its substantial health risks,” Steinbrook said. “The fact that a black box warning for brain swelling and bleeding risks has been added to the prescribing information for lecanemab underscores the substantial safety concerns.”

Patients with Alzheimer’s disease and their families are understandably desperate for better treatments, he said. However, Steinbrook added, when it approves drugs for Alzheimer’s disease with little or no benefit and significant health risks, the FDA fails patients and the public.

Families should consider the pros and cons of having a loved one take lecanemab carefully. In addition to possible harmful side effects, the drug also is very expensive. The cost, without coverage, could be more than $26,000 annually for the drug, which is delivered by an intravenous infusion every two weeks..