Earlier this week, the U.S. Food and Drug Administration (FDA) approved the new drug Aducanumab for the treatment of Alzheimer’s, using its ‘accelerated approved pathway’, which can be used for a drug for a serious or life-threatening illness that provides a meaningful therapeutic advantage over existing treatments.
It is the first new treatment approved for early Alzheimer’s since 2003 and is the first therapy that targets the underlying pathology of the disease. Aducanumab is an antibody treatment developed by the pharmaceutical company Biogen.
‘Alzheimer’s is a devastating condition that has a huge impact on the lives of people diagnosed with the disorder, as well as their loved ones,’ said Dr Penny Foulds, Neuroscience Team Leader at MAC Clinical Research and Honorary Researcher at Lancaster University. ‘Currently, available drug treatments only treat some of the symptoms of the disease. This new medication is the first therapy to target and affect the underlying disease process in Alzheimer’s.’
Alzheimer’s is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills, and eventually, the ability to carry out simple, daily tasks. While the specific causes of Alzheimer’s are not fully understood, it is characterized by changes (or pathology) in the brain—including amyloid plaques and tau tangles—that result in loss of brain nerve cells and their connections.
According to the amyloid hypothesis, co-written by the late Prof David Allsop of Lancaster University in 1991, accumulation of beta amyloid plaques in the brain is the primary influence driving the Alzheimer’s process in the brain. The degeneration of the brain, including formation of tau tangles, is proposed to result from an imbalance between beta amyloid production and beta amyloid clearance.
Researchers ran separate clinical trials to test the drug’s effectiveness (called EMERGE and ENGAGE), representing a total of 3,482 people living with mild cognitive impairment and early Alzheimer’s. Patients receiving the treatment had a significant dose, and time-dependent, reduction of beta amyloid plaques, while patients in the control arm of the studies (the placebo group) had no reduction in plaque load.
Beta amyloid beta plaque load was measured using a type of brain scan called Positron Emission Tomography (or PET) imaging, to estimate the brain levels of plaque in regions expected to be affected by Alzheimer’s pathology, compared to a brain region expected to be spared of such change.
Under the accelerated approval provisions, which provide patients living with the disease earlier access to the treatment, the FDA is requiring the company, Biogen, to conduct a new randomized, controlled clinical trial to verify the drug’s clinical benefit. If the trial fails to verify clinical benefit, the FDA may initiate proceedings to withdraw approval of the drug.
The UK regulator, the MHRA, are expected to give their decisions on whether to grant the drug a similar or different form of licence this autumn.
Dr Foulds says, ‘This decision will have a positive impact on the global search for effective dementia treatments. Aducanumab is only suitable for certain people with early Alzheimer’s, so renewed focus and investment in dementia research will speed up the search for life-changing treatments for those with other dementias, and in the later stages of Alzheimer’s.”
“Aducanumab will not be available for people living with early Alzheimer’s in the UK for a while yet, but MAC Clinical Research will continue to work with the pharmaceutical industry to ensure any new drug treatments are tested. Clinical research has the ability to change the lives of everyone affected by dementia and we will keep working to make more breakthroughs possible.”