FDA Gives Green Light to Lecanemab, Offering New Hope for Alzheimer’s Patients

In January 2023, U.S. Food and Drug Administration approved a new drug called Lecanemab for treating Alzheimer’s disease. Lecanemab is the second of the disease-modifying drugs approved for the treatment of Alzheimer’s disease. It is a significant step in developing treatments for slowing progression of the Alzheimer’s disease as this drug targets the pathological mechanisms involved in the development of Alzheimer’s.

What is Alzheimer’s disease?

Alzheimer’s disease is characterized by degeneration of neurons in the brain and progressive worsening of the symptoms that usually start with memory loss and the impairment in thinking and eventually, leading to loss of ability to carry out daily tasks. This disease primarily affects areas of the brain that are involved in the control of memory and thinking skills. It is an irreversible disease and there is no cure for the disease yet.

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What is known about the underlying pathology?

The underlying pathological mechanisms for the development of Alzheimer’s are not well known. Presently, the focus is on enhancing the understanding of the role of the abnormal buildup of proteins such as Amyloid beta proteins and neurofibrillary tangles in the brain. The current understanding is that the abnormal buildup of these proteins leads to the degeneration of neurons and their connective tissue in the brain which results in the symptoms of Alzheimer’s.

How common is Alzheimer’s disease?

Alzheimer’s is the most common cause of dementia in the US. It is estimated that around 6.5 million people aged 65 years or older in the US were living with a diagnosis of Alzheimer’s in 2022. It is also one of the 10 leading causes of death in the US. 1 in 3 people aged 65 years or older dies due to Alzheimer’s or another type of dementia.

What do current treatments aim at?

Currently, many drugs are being studied targeting these protein changes in the brain. They are at different stages of clinical studies. Previously, many drugs have been used to manage Alzheimer’s disease and they primarily targeted improvements in patients’ symptoms. Although these drugs help manage the associated symptoms and improve the daily lives of patients with Alzheimer’s, there is a significant need for finding better treatment options to prevent the onset and slow the progression of the disease itself.

What do the latest treatments aim to do?

It is not possible to reverse Alzheimer’s disease yet as there is no cure for it. Finding curative treatments for Alzheimer’s has been very challenging because the exact mechanism underlying the pathological changes in Alzheimer’s is still not well understood. There is evidence about changes in Amyloid beta plaques and neurofibrillary tangles in the brain result in the loss of neurons in the brain. Building on this hypothesis, many drugs have been studied to impair the onset or slow the development of the disease.

Read Also: Alzheimer’s Disease: MIT Study Shows How Tau Protein Tangles Form

What do disease-modifying drugs do?

The disease-modifying agents aim to remove or lower the number of Amyloid beta plaques in the brain and these can prove to be an effective way to treat Alzheimer’s in patients with mild cognitive impairment or early-stage disease by, essentially, preventing the onset of the disease. These drugs need to be given before the onset or at the earlier stages of the disease to achieve maximum benefit for the patients. Patients are screened for family history, and the presence of Amyloid beta proteins in the brain, and few diagnostic tests are performed to establish the stage of the disease and assess the patient’s eligibility for a prescription. The potential of the disease-modifying drugs for Alzheimer’s is estimated to be high and further studies are benign done to assess their effectiveness. Aducanumab was the first disease-modifying agent that was approved by FDA last year. Lecanemab is the second one.

How was Lecanemab approved?

FDA approved Lecanemab by Accelerated Approval pathway. In this pathway, U.S. Food and Drug Administration approves a drug for a serious condition that has shown some clinical benefit in early studies. It is also considered if the condition has an unmet need and if the drug has been shown to affect the surrogate endpoint (it is a measure that indicates potential benefit).

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Study results:

The results of a double-blind phase 3 clinical trial studying the effects of Lecanemab were submitted to FDA and they showed a reduction in amyloid beta plaque (it’s a marker of Alzheimer’s). Patients with mild cognitive impairment and an established presence of Amyloid beta plaques took the treatment. In the trial, patients with the above-mentioned characteristics showed a significant decrease in the number of Amyloid beta plaques and this observation favored the lecanemab’s accelerated approval by FDA.

Is Lecanemab recommended for every patient with Alzheimer’s?

Currently, Lecanemab is recommended by FDA for patients with mild cognitive deficits due to Alzheimer’s as it was studied in samples with similar characteristics. The drug is not recommended for use in earlier or later stages of the disease than the studied population as safety and effectiveness data for these stages of the disease are not available yet.

Where to find more information?

The availability of the drug may vary due to delays in manufacture, distribution, and access to it. The information related to availability, prescription, appropriateness for patients with mild cognitive impairment, and the cost is available on the webpage of the Alzheimer’s association. It is mentioned in the references section.

References

Lecanemab Gains FDA Approval for Early Alzheimer Disease (Accessed on March 10, 2023)

Aducanumab and disease modifying treatments for Alzheimer’s disease (Accessed on March 10, 2023)

The dawn of disease modification for Alzheimer’s disease: Hope and peril (Accessed on March 10, 2023)

Is the First Disease-Modifying Therapy for Alzheimer Disease on the Horizon? (Accessed on March 10, 2023)