Donanemab: For Early Alzheimer's Treatment

What Is Donanemab?

Donanemab is a drug used to treat early Alzheimer's disease (a brain condition that slowly affects memory, thinking, and daily functioning). It is a monoclonal antibody (a laboratory-made immune protein designed to target a specific substance) that binds to amyloid-beta plaques (harmful protein clumps that build up in the brain and damage brain cells).

Is Donanemab FDA-Approved?

Yes. The U.S. Food and Drug Administration gave full approval on July 2, 2024, for Donanemab to treat adults with early Alzheimer's disease who have confirmed amyloid plaques in the brain.

Following Donanemab approval, it became the second Alzheimer's disease medication to receive full approval, after Lecanemab. Both treatments carry a warning for amyloid-related imaging abnormalities, ARIA (brain swelling or small brain bleeds seen on brain scans). This is why doctors closely monitor patients during therapy.

How Does Donanemab Work?

The Donanemab mechanism of action involves attaching to a toxic form of amyloid and helping the brain's immune cells identify, break down, and remove these plaques.

Donanemab in early Alzheimer's disease works by targeting amyloid plaques in the brain. They are linked to memory loss and thinking problems.

Amyloid plaques block the normal communication between nerve cells. This will cause damage to the brain connections and trigger inflammation. Over time, this leads to memory loss and thinking difficulties.

Because of this targeted action, Donanemab slows disease progression rather than providing a complete cure for Alzheimer's.

Who Can Receive Donanemab Therapy?

Donanemab may be an option for people who have early Alzheimer's disease and show amyloid plaques in the brain. It is meant only for people in the early stages, not for those with advanced Alzheimer's disease or people without symptoms.

Who usually qualifies for this treatment? People who may be eligible often have:

• Mild cognitive impairment (early memory problems, forgetfulness, or confusion).

• Mild dementia (difficulty doing familiar daily tasks, such as managing finances or remembering appointments).

How Do Doctors Decide if Donanemab Is Suitable for You?

There is no single test that confirms Alzheimer's disease. So, how do doctors decide if

Donanemab is right for someone? Doctors use various tests and evaluations for that, including:

• Review of personal and family medical history.

• Memory and thinking tests to assess mental function.

• Physical and nerve examinations.

• Blood tests to understand other causes of memory problems.

• Spinal fluid test (a small sample of fluid taken from the lower back to check for Alzheimer 's-related proteins).

• Brain MRI (magnetic resonance imaging) to examine brain structure and exclude other conditions.

• Brain PET (positron emission tomography) to confirm the presence of amyloid plaques.

Together, these tests help doctors decide whether Donanemab treatment is appropriate and safe for a patient.

Is Donanemab Effective?

Studies suggest strong Donanemab efficacy, with the drug slowing memory and thinking decline by over 20 %, especially when started early in the disease. After one year, nearly half of the patients had no decline in memory and thinking, and there was about a 40 % reduction in difficulty with daily activities.

However, these results are based on an 18-month study, so the long-term benefits are still being studied. More diverse clinical trials are also needed to confirm Donanemab's efficacy across all populations.

How Is Donanemab Given?

Donanemab for Alzheimer’s treatment is given as an IV (intravenous) infusion (medicine delivered into a vein in your arm). Each infusion takes about 30 minutes. The treatment is given once every four weeks.

What Should You Do if You Missed a Dose?

If you miss a Donanemab infusion, you should receive your next dose as soon as possible and then continue the schedule every four weeks.

Donanemab Dosing Schedule:

Donanemab starts with lower doses that slowly increase over the first few treatments to help your body adjust. Typical adult dosing is every four weeks:

• 1st infusion: 350 mg.

• 2nd infusion: 700 mg.

• 3rd infusion: 1,050 mg.

• 4th infusion and onward: 1,400 mg.

What Are the Side Effects of Donanemab?

Common Side Effects of Donanemab:

ARIA (brain swelling or bleeding). Symptoms may include:

• Headache.

• Confusion.

• Dizziness.

• Vision changes.

• Trouble walking or loss of balance.

• Nausea.

• Falls.

• Seizures.

Infusion-related reactions (side effects that happen during or shortly after the IV treatment):

• Fever or chills.

• Headache.

• Skin rash or hives.

• Flushing or sweating.

• Changes in blood pressure.

• Trouble breathing.

• Chest pain.

• Nausea or vomiting.

• Pale skin.

Other common Donanemab side effects:

• Back pain.

• Weakness or fatigue.

• Skin irritation at the infusion site.

Serious Side Effects:

Severe ARIA:

• Severe or worsening headache.

• Sudden confusion.

• Seizures.

• Vision loss.

• Slurred speech.

• Trouble walking.

• Severe weakness or loss of balance.

Severe Allergic Reactions:

• Swelling of the face, tongue, or throat.

• Widespread hives.

• Difficulty breathing.

Monitoring and Risk Factors

• Regular brain scans are required to detect Donanemab side effects.

• Blood tests and checkups may be needed to ensure Donanemab treatment is working and to monitor for Donanemab side effects.

• Some people may have infusion-related reactions during or after treatment. Tell your doctor immediately if you feel feverish, dizzy, confused, or short of breath; have chest tightness, chills, headache, or nausea; or have unusual tiredness.

• Donanemab may not be suitable for people taking certain blood-thinning medications or with cerebral amyloid angiopathy (a condition that weakens brain blood vessels), as it increases the chances of bleeding.

• Avoid taking any new medicines, vitamins, or herbal supplements unless your doctor approves them.

When to Seek Help While Using Donanemab?

If you notice any symptoms, like headaches, confusion, dizziness, changes in your vision, nausea, or seizures, then contact your doctor. These symptoms may be signs of ARIA (a side effect of Donanemab), which involves temporary swelling or bleeding in the brain.

Paying attention to warning signs and acting quickly can make a big difference. If anything feels wrong, please contact your nerve specialist right away.

Conclusion

Donanemab for the treatment of early Alzheimer's disease works by slowing disease progression. It targets amyloid plaques in the brain.

Donanemab is not a complete cure for Alzheimer's disease. Starting Donanemab treatment early may help patients reduce memory issues, improve their thinking ability, and maintain independence for a longer time.

If you or a loved one is going through the hardships of Alzheimer's disease, then seek a consultation with a brain doctor. They can evaluate and see whether Donanemab may be appropriate for you. Early action can make a meaningful difference in each Alzheimer's patient's life.

Key Takeaways

• Donanemab is approved for early-stage Alzheimer's disease treatment (not advanced disease).

• Donanemab treatment may slow memory and thinking issues, but it does not cure Alzheimer's.

• Regular medical monitoring is required while taking Donanemab due to the risk of side effects.