After taking Aduhelm, the patient was hospitalized and diagnosed with swelling in the brain before dying. It isn’t known yet whether the brain swelling was related to Aduhelm, Biogen said Tuesday.
Brain swelling was among the most common side effects found during testing of the drug. Aduhelm’s prescribing information warns about the risk of a brain-swelling condition known as ARIA-E.
The patient’s death was reported by a doctor to a Food and Drug Administration drug-safety database during the third quarter. Doctors reported other side effects among Aduhelm patients to the database.
"All the recently published cases related to Aduhelm are under careful review as well as medical evaluation, including the fatal case of a 75-year-old patient whose cause of death remains under investigation and who was diagnosed during hospitalization with cerebral edema thought to be ARIA-E," the company said.
More than 80% of the ARIA-E cases reported during clinical testing were resolved within four months, according to the company’s presentation to FDA advisers.
Biogen also said it believes the benefits of Aduhelm outweigh the risks.
The report of the patient’s death was first reported on Monday by RBC analyst Brian Abrahams. While it is hard to definitely assign a cause of death, Mr. Abrahams said, the patient was "not particularly old and did not appear to have any other contributing conditions listed."
Biogen’s stock closed down 2.15% on Monday and dropped 1.82% during trading Tuesday morning.
If the patient’s death is linked to Aduhelm it could further contribute to the hesitancy of many physicians to prescribe it, Mr. Abrahams said.
In June, the Food and Drug Administration approved Aduhelm. It was the first new Alzheimer’s drug to get a thumbs-up from the agency in decades, but some agency staff and Alzheimer’s experts said there was insufficient evidence to support approval.
The drug reduces a sticky protein called amyloid that builds up in the brain. The FDA said that reducing amyloid is likely to slow the cognitive decline caused by Alzheimer’s, but approved it under an accelerated approval pathway that requires further research to verify the clinical benefit.
ARIA-E stands for amyloid-related imaging abnormality-edema, and refers to the buildup of fluid in the brain that can result in swelling and in some cases, bleeding.
Aduhelm’s approval was met with criticism from some doctors and health economists, who expressed concern the drug’s $56,000 annual cost would add billions of dollars in new healthcare spending for a treatment with uncertain effectiveness and the potential for serious side effects.