Donanemab provides greater brain amyloid clearance than aducanumab in early Alzheimer’s

19th December 2022

Donanemab has been shown to clear more brain amyloid than aducanumab in a head-to-head study in patients with early Alzheimer’s disease

According to a press release by drug manufacturer Lilly, donanemab provides a greater level of brain amyloid clearance compared to aducanumab at 6 months.

Brain amyloid-β deposition is a hallmark used to define Alzheimer’s disease. Moreover, in March 2022, the Food and Drug administration (FDA) in the US, approved the first in vitro diagnostic test for early detection of amyloid plaques associated with Alzheimer’s disease. The FDA added that a positive test was consistent with the presence of amyloid plaques, similar to what would be seen in a PET scan and that a negative result is consistent with a negative amyloid PET scan result, reducing the likelihood that a patient’s cognitive impairment was due to Alzheimer’s disease, enabling physicians to pursue other causes of cognitive decline and dementia.

The current data announced by Lilly, comes from the TRAILBLAZER-ALZ 4 trial, which was a randomised, open-label phase 3 study designed to compare donanemab (DM) with aducanumab (AM) on amyloid plaque clearance in participants with early, symptomatic Alzheimer’s Disease. In the trial, donanemab and aducanumab were administered via intravenous infusions every four weeks for up to 18 months.

Donanemab efficacy

In the co-primary outcomes, brain amyloid plaque clearance, defined as achieving brain amyloid plaque levels of <24.1 Centiloids, was achieved in 37.9% of DM-treated participants compared with 1.6% of AM-treated patients at 6 months. In the intermediate tau subpopulation, 38.5% of DM-treated participants reached brain amyloid clearance compared with 3.8% of AM-treated participants by 6 months. In a key secondary outcome, DM reduced brain amyloid levels vs. baseline by 65.2% compared with 17.0% for AM at 6 months. In an exploratory outcome, donanemab, but not aducanumab treatment significantly reduced plasma P-tau217 at 6 months compared to baseline.

In terms of safety, amyloid-related imaging abnormalities were the most common treatment emergent adverse event in both groups and occurred with a similar frequency (25.4% vs 26.1%, DM vs AM).

Although only 6-month data is currently, available, the press release describes how TRAILBLAZER-ALZ 4 is an on-going study and results from 12 or 18 months will be presented once available.

FDA grants aducanumab approval for Alzheimer’s disease

10th June 2021

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.