FDA Approves Second Alzheimer’s Drug for Slowing Disease Progression

Alzheimer's and dementia research, conceptual image

(WASHINGTON) — The U.S. Food and Drug Administration (FDA) has granted approval to a second Alzheimer’s drug, Kisunla (donanemab) developed by Eli Lilly, offering a new treatment option for individuals in the early stages of this debilitating condition.

Approved on Tuesday, Kisunla is indicated for mild or early cases of dementia associated with Alzheimer’s disease. It joins Leqembi, a drug from Japanese pharmaceutical company Eisai, as the only medications demonstrably slowing cognitive decline in Alzheimer’s patients.

The delay in cognitive decline achieved with both drugs, however, is a matter of months—approximately seven months for Lilly’s drug. Patients and their families will need to carefully consider this benefit against potential drawbacks, such as the need for regular intravenous (IV) infusions and the risk of serious side effects, including brain swelling.

Physicians specializing in the treatment of Alzheimer’s view this approval as a significant step forward after decades of failed experimental therapies.

“I’m excited to have new treatment options for my patients,” stated Dr. Suzanne Schindler, a neurologist at Washington University in St. Louis. “As a dementia specialist, it has been challenging—diagnosing patients with Alzheimer’s and witnessing their progressive decline until their passing.”

Both Kisunla and Leqembi are laboratory-produced antibodies administered intravenously. They work by targeting amyloid plaque buildup, a key factor contributing to Alzheimer’s. Questions remain regarding the optimal patient population for these drugs and the duration of their effectiveness.

The approval of this new drug was anticipated following a unanimous recommendation by an independent FDA advisory panel in favor of its benefits at a public meeting last month. This endorsement came despite concerns raised by FDA reviewers regarding the methodology of Lilly’s clinical trial, particularly allowing patients to discontinue treatment once their plaque levels reached a very low point.

Lilly has indicated that the cost of treatment will vary based on individual patient needs and duration of use. The company has stated that a year of Kisunla therapy would cost $32,000, exceeding the $26,500 price tag for a year’s worth of Leqembi.

The FDA prescribing information advises physicians to consider halting treatment after confirming minimal plaque levels through brain scans.

The FDA’s approval of Kisunla (donanemab) is based on findings from an 18-month clinical trial. Patients receiving Kisunla demonstrated a 22% slower decline in memory and cognitive abilities compared to those receiving a placebo infusion.

The primary safety concern associated with Kisunla is brain swelling and bleeding, a common complication with all plaque-targeting drugs. The rates reported in Lilly’s study—including 20% of patients experiencing microbleeds—were slightly higher than those observed with Leqembi. However, the two drugs were tested on slightly different patient groups, making direct safety comparisons challenging for experts.

Kisunla is administered once a month, in contrast to Leqembi’s twice-a-month regimen, potentially simplifying the burden on caregivers who transport their loved ones to hospitals or clinics for treatment.

“Certainly, a monthly infusion is more appealing than bi-weekly infusions,” Schindler acknowledged.

Lilly’s drug offers another potential advantage: patients can cease treatment if they respond favorably.

In Lilly’s study, patients were withdrawn from Kisunla once their brain plaque levels reached low levels. Discontinuing the drug could potentially reduce the costs and safety risks associated with long-term use. The timing of any necessary resumption of infusions remains unclear.

Logistical obstacles, uneven insurance coverage, and financial concerns have all hindered the rollout of Leqembi, which Eisai markets in partnership with Biogen in the United States. Many smaller hospitals and healthcare systems are not yet equipped to prescribe these new plaque-targeting drugs.

Initially, physicians need to confirm the presence of the specific brain plaque targeted by these new drugs in patients with dementia. They must then locate a drug infusion center for patients to receive treatment. Additionally, nurses and other staff require training to perform repeated scans to monitor for brain swelling or bleeding.

“These are all essential components that a physician must have in place,” explained Dr. Mark Mintun, head of Lilly’s neuroscience division. “Until they become familiar with these procedures, a patient presenting in their office will not be offered this therapy.”

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