“As soon as the product is approved, the cat is out of the bag and the horse out of the stable,” said Dr. G. Caleb Alexander, FDA Advisory Committee member, internist, epidemiologist, and expert on drug safety and efficacy at the Johns Hopkins Bloomberg School of Public Health. “There is no way to regain the ability to understand if the product really works after approval.”
Companies can conduct post-market studies with participants from other countries, but may face similar challenges in recruiting participants if those countries approve the drug before the studies are completed. the drug has not yet been approved outside of the United States, but Biogen has requested regulatory reviews in the European Union, Japan, Brazil, and elsewhere.
Aduhelm is a monoclonal antibody that targets a protein, amyloid, that clumps together in plaques in the brains of Alzheimer’s patients and is believed to be a biomarker of the disease. Critics and supporters of the approval agree: the drug significantly lowers amyloid levels. The FDA said the drug’s effect on a biomarker qualifies it for the accelerated approval program.
However, reducing amyloid is not the same as slowing down symptoms of dementia. In more than two decades of clinical trials, many amyloid-lowering drugs failed to address symptoms, a history that some experts say made it particularly important that aducanumab’s data be convincing.
“Although the Aduhelm data are complicated in terms of clinical benefit, the FDA has determined that there is substantial evidence that Aduhelm reduces amyloid beta plaques in the brain and that reducing these plaques is likely to have important benefits for the patient, “said Dr Cavazzoni of the FDA wrote on the agency’s website.
Biogen officials said the drug provided long-awaited support for a theory that if done early enough, an attack on amyloid can help. Proponents of the approval also said it is possible that eliminating amyloid early could help contain the disease over time and provide added benefit beyond the slightly delayed early decline. However, Alzheimer’s experts point out that the assumption is completely untested.
