The US Food and Drug Administration (FDA) has granted accelerated approval for the monoclonal antibody, aducanumab, a first-in-class drug, for treatment for Alzheimer’s disease.
Alzheimer’s disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills and ultimately, the ability to carry out simple tasks. The precise cause of the disease is still not fully clear but a defining feature in the brain of sufferers is an accumulation of amyloid beta plaques and neurofibrillary, or tau, tangles which result in loss of neurons and their connections. Aducanumab (Aduhelm) works by targeting the aggregated soluble and insoluble amyloid beta plaques.
The efficacy of Aduhelm has been evaluated in three separate studies with a total of 3078 patients and which have been described in the manufacturer’s prescribing information leaflet. The dosage is 10mg/kg and the drug is administered over one hour every 4 weeks and available at two different strengths, 170 mg and 300mg.
In clinical studies, the effect of Aduhelm on amyloid plaques was assessed in the trials using positron emission tomography (PET) and resulted in significant reductions in plaques after 26 and 78 weeks of treatment. Writing on the FDA site, Dr Patrizia Cavazzoni, Director, FDA Center for Drug Evaluation and Research noted that “the data included in the applicant’s submission were highly complex and left residual uncertainties regarding clinical benefit.” Nonetheless, she also added that “the Agency concluded that the benefits of Aduhelm for patients with Alzheimer’s disease outweighed the risks of the therapy.”
Additionally, the FDA is requiring the manufacturer, Biogen, to conduct a post-approval clinical trial to verify the drug’s clinical benefit. If the drug does not work as intended, then the FDA can take steps to remove it from the market.