FDA Approves Donanemab for Early-Stage Alzheimer's Treatment

On July 2, 2024, the FDA officially approved Eli Lilly’s new Alzheimer’s medication, donanemab. Sold under the brand name Kisunla, this drug marks a major step forward for patients in the early stages of the disease. It offers concrete hope for slowing cognitive decline and preserving daily function.

What is Donanemab (Kisunla)?

Kisunla belongs to a class of medications known as amyloid beta-directed antibodies. Alzheimer’s disease is characterized by the buildup of toxic amyloid plaques in the brain. These sticky proteins disrupt communication between brain cells and eventually cause those cells to die.

Kisunla works by targeting these specific plaques and helping the immune system clear them away. It is strictly approved for patients with early symptomatic Alzheimer’s disease. This includes individuals with mild cognitive impairment or the mild dementia stage of the disease. Patients must also have a confirmed presence of amyloid plaques in their brains before starting the medication.

How Effective is the Treatment?

To understand the true impact of Kisunla, we have to look at the TRAILBLAZER-ALZ 2 clinical trial. This Phase 3 study followed over 1,700 patients for 18 months. The results were highly encouraging for those in the earliest stages of the disease.

Patients taking Kisunla experienced a 35% slower rate of clinical decline compared to those taking a placebo. This percentage represents a meaningful delay in disease progression. For a patient, a 35% slower decline means holding onto memories a little longer. It means retaining the ability to manage finances, drive a car, or participate in family conversations for months longer than they would without the drug. The drug is not a cure, but it gives patients more time at a higher level of daily functioning.

The Advantage of Finite Dosing

One of the most unique features of Kisunla is its finite dosing schedule. Other Alzheimer’s medications on the market, such as Leqembi (lecanemab), require continuous treatment for the rest of a patient’s life. Kisunla operates differently.

Because it is highly effective at clearing amyloid plaques, patients can actually stop taking the drug once brain scans show the plaques are gone. In the clinical trials, nearly 17% of patients completed their treatment in just six months. About 47% completed their treatment within a year. This ability to stop therapy provides several benefits:

• Reduces the long-term financial cost of the drug.
• Minimizes the burden of frequent hospital visits for patients and caregivers.
• Lowers the risk of prolonged side effects.

Administration and Costs

Kisunla is administered via an intravenous (IV) infusion. Patients must visit a clinic or hospital once every four weeks to receive the medication. Each infusion takes about 30 minutes. This four-week schedule offers a slight convenience advantage over Leqembi, which requires infusions every two weeks.

The financial aspect of this treatment requires careful planning. Eli Lilly set the list price for a 12-month course of Kisunla at approximately $32,000. Because of the finite dosing, the total cost depends entirely on how long a patient actually needs the drug. For example, a six-month course costs roughly $12,522.

Medicare does cover Kisunla for eligible patients under Part B. However, standard out-of-pocket limits and co-insurance rates still apply. Patients should consult their Medicare provider to understand their specific financial responsibilities.

Potential Risks and Side Effects

Like all powerful medications, Kisunla comes with serious risks. The FDA attached a boxed warning to the drug concerning a condition called Amyloid-Related Imaging Abnormalities (ARIA). ARIA is a known side effect of amyloid-clearing antibodies. It can manifest in two ways:

• ARIA-E: Swelling or edema in the brain.
• ARIA-H: Small bleeds or microhemorrhages in the brain.

Most cases of ARIA are asymptomatic and resolve on their own. However, severe cases can be life-threatening. Symptoms of severe ARIA include sudden confusion, dizziness, vision changes, and severe headaches. To manage this risk, patients must undergo regular MRI scans before and during the early months of treatment. These scans allow doctors to spot brain swelling or bleeding early and pause the medication if necessary.

Preparing for Treatment

Before starting Kisunla, patients go through a rigorous screening process. Doctors will review a patient’s medical history to check for factors that might increase the risk of ARIA.

For example, patients carrying the APOE4 gene mutation face a significantly higher risk of experiencing brain swelling or bleeding. Genetic testing is highly recommended before beginning the infusions. Additionally, patients taking blood thinners must proceed with extreme caution, as these medications can complicate brain bleeds. A doctor must also confirm the presence of amyloid plaques using a PET scan or a cerebrospinal fluid test. If a patient does not have these plaques, the drug will not work for them.

Frequently Asked Questions

Is Donanemab a cure for Alzheimer’s disease? No. Kisunla (donanemab) is not a cure. It is a disease-modifying treatment designed to slow the progression of cognitive decline in the early stages of Alzheimer’s.

How long does a patient have to take Kisunla? Treatment length varies by patient. Because Kisunla uses a finite dosing model, patients stop taking the drug once brain scans confirm that the amyloid plaques have been cleared. In clinical trials, many patients achieved this within 6 to 18 months.

Can late-stage Alzheimer’s patients take this drug? No. The FDA specifically approved Kisunla for early symptomatic Alzheimer’s disease. Patients in moderate to severe stages of the disease are not eligible for this medication.

Does Medicare cover the cost of the required brain scans? Yes. Medicare recently broadened its coverage to include PET scans used to diagnose Alzheimer’s disease. Medicare will also cover the routine MRI scans required to monitor for ARIA side effects during the treatment process.