US FDA narrows patient group for Biogen’s Alzheimer's drug after sharp criticism

Aduhelm is the first Alzheimer's medication approved by the US FDA in nearly 20 years.

The US Food and Drug Administration (FDA) has narrowed down the group of patients that can use the Alzheimer's disease drug, Biogen Inc announced on Thursday. The company said in a statement that treatment with Aduhelm should be initiated in patients with mild cognitive impairment or mild dementia stage of disease, the population in which treatment was initiated in clinical trials.

“There are no safety or effectiveness data on initiating treatment at earlier or later stages of the disease than were studied,” the company added.

Aduhelm is the first Alzheimer's medication approved by the FDA in nearly 20 years. The US drug regulator’s approval of Aduhelm last month drew sharp criticism over the effectiveness of the drug. Three experts even resigned from an FDA committee over the agency’s decision to approve a medicine that only slowed the mental decline in one study that was marred by hard-to-interpret results.

“Based on our ongoing conversations with prescribing physicians, FDA and patient advocates, we submitted this label update with the goal to further clarify the patient population that was studied across the three Aduhelm clinical trials that supported approval,” Alfred Sandrock, Jr., head of research and development at Biogen, said in a statement.

Alzheimer’s disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills, and eventually, the ability to carry out simple tasks. Before Thursday's announcement, the FDA approval wasn't limited to early patients or those with mild cognitive impairment. But anyone with Alzheimer's, at least theoretically, could get the drug prescribed.

The drug can cause serious side effects including Amyloid Related Imaging Abnormalities, or “ARIA”, a side effect that does not usually cause any symptoms but can be serious. ARIA is most commonly seen as temporary swelling in areas of the brain that usually resolves over time and some people may also have small spots of bleeding in or on the surface of the brain with the swelling, said Biogen.