FDA Narrows Recommendation for New Alzheimer Drug

This article was updated at 10:30 am on July 9, 2021.

Following its approval of aducanumab (Aduhelm, Biogen) for the treatment of Alzheimer disease in June 2021, officials with the FDA have now recommended that it only be given to adults with mild symptoms.¹

“Alzheimer’s disease is a devastating illness that can have a profound impact on the lives of people diagnosed with the disease as well as their loved ones,” said Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research, in an FDA press release. “Currently available therapies only treat symptoms of the disease; this treatment option is the first therapy to target and affect the underlying disease process of Alzheimer’s.”²

Aducanumab was approved under the accelerated approval pathway and is a first-of-its-kind treatment for Alzheimer disease. Its efficacy was evaluated in 3 separate studies including 3282 patients. According to an FDA press release, patients who received the treatment had significant dose- and time-dependent reduction of amyloid beta plaque, whereas patients in the control arm had no reduction.³

“Our current treatments for things like Alzheimer’s disease and some of these degenerative dementias are symptomatic medications…they all try to help the symptoms,” said Douglas Scharre, MD, a neurologist and director of the division of Cognitive Neurology at Ohio State Wexner Medical Center, in an interview released by the medical center. “But none of them that are available right now get to what a lot of people think are the core issues to modify the disease.”⁴

This reduction of amyloid beta plaque in the brain was a surrogate endpoint supporting the drug’s approval. According to the FDA press release announcing aducanumab’s approval, the presence of amyloid beta plaque in the brain is a hallmark of Alzheimer disease. Investigators in the clinical trials quantified the plaque using positron emission tomography imaging.³

Despite these findings, the FDA has faced criticism for its approval, according to reporting by The New York Times. Many scientists said that the evidence was insufficient for approval and the FDA’s independent advisory committee advised against approval in November of 2020. The agency’s original label was also quite broad, resulting in concern from many experts.¹

According to The New York Times, one late-stage clinical trial found that the highest dose slowed patients’ cognitive decline by a fraction of a point on an 18-point scale evaluating memory, problem-solving skills, and function. A second, identically designed trial, however, found that the drug showed no benefit at all.¹

The new label specifies that aducanumab should be used in patients with “mild cognitive impairment or mild dementia stage of disease,” which aligns with the population studied in clinical trials.⁵ The label adds that there are no safety or efficacy data on initiating treatment at earlier or later stages of disease.⁵

A press release from the Alzheimer's Association agreed with this new recommendation.⁶

"Today's announcement is consistent with the Alzheimer's Association position that Aduhelm should be made available specifically to the population represented in the clinical trials where there was evidence of clinical benefit," said Maria C. Carrillo, PhD, chief science officer of the Alzheimer's Association, in the press release. "We appreciate the FDA's thoughtful consideration and response to the Alzheimer's Association and others in the community including physicians, researchers, and patients to ensure this treatment is prescribed only to those who may see benefit."⁶

The updated label still includes a warning for amyloid-related imaging abnormalities, which usually present as brain swelling.⁵ This swelling typically resolves over time and does not cause symptoms, although some patients may experience headache, confusion, dizziness, vision changes, or nausea.³

Aducanumab also includes risks of hypersensitivity reactions, including angioedema and urticaria. The most common adverse effects observed in clinical trials included amyloid-related imaging abnormalities, headache, fall, diarrhea, and confusion or altered mental status.³ As part of the accelerated approval provisions, the FDA is requiring Biogen to conduct a new randomized, controlled clinical trial to prove the drug’s clinical benefit.³

REFERENCE

1. Robbins R and Belluck P. In a Reversal, FDA Calls for Limits on Who Gets Alzheimer’s Drug. New York Times. July 8, 2021. Accessed July 8, 2021. https://www.nytimes.com/2021/07/08/health/aduhelm-alzheimers-fda.html?action=click&module=Top%20Stories&pgtype=Homepage

2. FDA Grants Accelerated Approval for Alzheimer’s Drug. News release. FDA. June 7, 2021. Accessed July 8, 2021. https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-alzheimers-drug

3. Antrim A. FDA Approves First New Alzheimer’s Drug in Nearly 2 Decades. Pharmacy Times. June 7, 2021. Accessed July 8, 2021. https://www.pharmacytimes.com/view/fda-approves-first-new-alzheimer-s-drug-in-nearly-2-decades

4. Ohio State University Wexner Medical Center. Dr. Douglas Scharre on FDA approval of new drug to treat Alzheimer’s Disease. June 4, 2021. Accessed June 7, 2021. http://osuwmc.multimedia-newsroom.com/index.php/2021/06/04/dr-douglas-scharre-on-pending-fda-approval-of-new-drug-to-treat-alzheimers-disease/

5. Aducanumab-avwa Prescribing Information. Biogen. Updated July 2021. Accessed July 8, 2021. https://www.biogencdn.com/us/aduhelm-pi.pdf

6. Alzheimer's Association Welcomes Revised Label for Aduhelm. News release. Alzheimer's Association. July 8, 2021. Accessed July 9, 2021. https://www.alz.org/news/2021/fda-revises-label-for-aduhelm-aducanumab