The New Frontier in Alzheimer's Care: A Guide to Injectable Treatments

Recent breakthroughs in Alzheimer’s research have brought a new sense of hope for patients and their families. If you are seeking to understand the latest advancements, you have come to the right place. This guide offers a clear, detailed look at the new class of injectable treatments that are changing how we approach this challenging disease.

A Major Shift in Alzheimer's Strategy

For decades, Alzheimer’s treatments primarily focused on managing symptoms. However, a new wave of therapies takes a different approach by targeting the underlying biology of the disease. Scientists have long identified two key proteins, beta-amyloid and tau, that build up in the brains of people with Alzheimer’s. Beta-amyloid forms sticky plaques between nerve cells, while tau creates tangles within them, both of which disrupt communication and lead to cell death.

The latest developments are centered on a type of treatment called monoclonal antibody therapy. These are lab-engineered proteins that act like the body’s natural antibodies. They are designed to identify, target, and help clear the harmful amyloid plaques from the brain. Because these are large protein molecules, they cannot be taken as a pill and must be administered directly into the bloodstream through an injection or infusion. This method represents a significant leap forward from symptom management to actively modifying the course of the disease.

Spotlight on Key Injectable Medications

Several injectable drugs have been at the forefront of this new era in Alzheimer’s care. They work in similar ways but target different forms of amyloid protein. It is important to note that these treatments are intended for individuals in the early stages of Alzheimer’s disease, including those with mild cognitive impairment.

Lecanemab (Brand Name: Leqembi)

Lecanemab, sold under the brand name Leqembi, is one of the most significant recent developments. In 2023, it received full approval from the U.S. Food and Drug Administration (FDA) for the treatment of early Alzheimer’s disease.

  • How it Works: Leqembi is specifically designed to target and clear protofibrils, which are soluble, toxic clumps of amyloid that are thought to be a key contributor to the nerve cell damage in Alzheimer’s. By removing these early-stage plaques, the drug aims to slow down the disease’s progression.
  • Administration: It is administered as an intravenous (IV) infusion every two weeks. Each session typically takes about an hour and is done at a hospital or infusion center.
  • Proven Efficacy: Clinical trials, most notably the Clarity AD study, showed that Leqembi slowed the rate of cognitive decline by 27% over 18 months compared to a placebo. This means that while it is not a cure, it can provide patients with more time in the earlier, more independent stages of the disease.
  • Potential Side Effects: The most common side effects are amyloid-related imaging abnormalities, known as ARIA. These are temporary swelling (ARIA-E) or bleeding (ARIA-H) in the brain, which are usually mild and resolve on their own but require regular monitoring with MRI scans.

Donanemab

Donanemab is another promising monoclonal antibody that has shown positive results in clinical trials. While it is not yet FDA-approved as of early 2024, it is expected to be reviewed soon.

  • How it Works: Donanemab takes a slightly different approach by targeting established, dense amyloid plaques that have already formed in the brain. The goal is to clear these larger deposits to slow further damage.
  • Administration: Similar to Leqembi, Donanemab is given as an IV infusion, but typically once every four weeks.
  • Proven Efficacy: In its TRAILBLAZER-ALZ 2 clinical trial, Donanemab was shown to slow cognitive and functional decline by about 35% over 18 months in a specific patient population. A unique aspect of the trial was that some patients were able to stop treatment once their amyloid plaques were cleared to a certain level.
  • Potential Side Effects: Donanemab also carries the risk of ARIA, and monitoring via MRI is a critical part of the treatment protocol.

Aducanumab (Brand Name: Aduhelm)

Aducanumab was the first of these amyloid-targeting therapies to receive FDA approval in 2021. Its approval was controversial because the clinical trial data on its effectiveness was complex and debated among scientists.

  • How it Works: Aduhelm also targets and removes amyloid plaques from the brain.
  • Current Status: Due to the controversy and limited insurance coverage, its use has been very limited. It served as a trailblazer for this class of drugs, paving the way for the more recent treatments with clearer clinical trial results.

Who Is a Candidate for These Treatments?

A crucial aspect of these new therapies is patient selection. They are not suitable for everyone with memory concerns. To be eligible, a patient must meet specific criteria:

  1. Confirmed Diagnosis: The patient must have a diagnosis of Mild Cognitive Impairment (MCI) due to Alzheimer’s disease or be in the mild dementia stage of Alzheimer’s. These drugs have not been shown to be effective in later stages of the disease.
  2. Presence of Amyloid Plaques: Before starting treatment, a doctor must confirm the presence of amyloid plaques in the brain. This is done through a positron emission tomography (PET) scan or by analyzing cerebrospinal fluid obtained from a lumbar puncture (spinal tap).
  3. Safety Screening: Patients undergo MRI scans before and during treatment to monitor for ARIA. Those with certain risk factors, such as carrying two copies of the APOE4 gene, may have a higher risk of side effects and require careful consideration.

What to Expect During Treatment

The patient experience involves a significant commitment. Treatment requires regular visits to an infusion center. Before starting, the medical team will conduct baseline assessments, including cognitive tests and MRI scans. During the treatment period, patients are monitored closely for any adverse reactions. The ongoing MRI scans are essential to catch any signs of ARIA early, even if the patient has no symptoms.

It is vital for patients and caregivers to have open conversations with their neurologists about the potential benefits versus the risks and logistical demands of these infusion therapies.

Frequently Asked Questions

Do these new injections cure Alzheimer’s disease? No, these treatments are not a cure. They are designed to slow the progression of the disease in its early stages. By clearing amyloid from the brain, they can help preserve cognitive function for a longer period, but they do not reverse existing damage or stop the disease process entirely.

Are these treatments covered by insurance? Following its full FDA approval, Medicare announced that it would cover Leqembi for eligible patients. Coverage policies for other private insurers can vary. Donanemab’s coverage will be determined if and when it receives FDA approval. Patients should always verify coverage with their insurance provider.

What is the most important side effect to know about? The most significant side effect is ARIA (amyloid-related imaging abnormalities). While often asymptomatic, in rare cases it can be serious. This is why regular MRI monitoring is a mandatory part of the treatment protocol to ensure patient safety.

How can I find out if my loved one is eligible for these treatments? The first step is to consult with a neurologist or a specialist at a memory clinic. They can perform the necessary cognitive assessments and order the diagnostic tests (like a PET scan) required to determine if a patient has early-stage Alzheimer’s with confirmed amyloid plaques, making them a potential candidate for these therapies.