New Alzheimer’s Drugs (October 2024) – Conversations to Remember

On July 2, 2024, the US Food and Drug Administration (FDA) approved donanemab-azbt, known by the brand name Kisunla, as a treatment for early-stage Alzheimer’s disease. This was exciting news for Alzheimer’s patients and a significant victory for researchers, given that Kisunla is only the second approved anti-amyloid treatment to target Alzheimer’s-related cognitive decline, following approval of Leqembi (lecanemab-irmb) in 2023. Another drug, Aduhelm (aducanumab-avwa), received accelerated approval in 2021, but its manufacturer, Biogen, discontinued it in early 2024 to redistribute resources towards other clinical trials.

Alzheimer’s disease is the most common type of progressive dementia, characterized by cognitive impairments, including memory loss, personality changes, and difficulty performing activities of daily living. Although the exact cause of Alzheimer’s is still unknown, researchers have identified amyloid precursor proteins and tau proteins as key indicators of disease progression. These proteins normally stabilize connections and transport of nutrients between neurons, but once protein fragments build up to abnormal levels in or around neurons, the brain gradually loses its ability to communicate between different regions. The body still tries to remove the resulting amyloid plaque and neurofibrillary tangle aggregates, but is unable to keep pace with the build up, leading to the characteristic rapid brain degeneration of Alzheimer’s disease.

As an amyloid plaque-targeting therapy, Kisunla is administered intravenously every four weeks. In phase 3 of the clinical trial sponsored by Eli Lilly and Company, 1736 participants with early symptomatic Alzheimer’s disease were screened and selected starting in 2020 to receive Kisunla or a placebo for up to 76 weeks. Ultimately, researchers concluded using imaging tests that treatment significantly slowed disease progression and decreased brain amyloid plaque levels in participants, both when comparing those with a less advanced disease and among the overall clinical population. Despite the efficacy of Kisunla, the clinical trial also revealed potential side effects, as some individuals had serious adverse reactions to treatment, including allergic reactions, headache, and brain swelling or bleeding, which were life-threatening in a few reported cases.

Compared to Leqembi, which also clears amyloid plaques from the brain through biweekly administrations and must be used continually, Kisunla can be stopped after beta-amyloid levels decrease significantly. Otherwise, the side effects between treatments are comparable, and individuals are recommended to discuss the risks and benefits with their primary care physician about which treatment might be beneficial for them.

It is important to note that while Kisunla, as well as other treatments undergoing study, show promise treating Alzheimer’s disease, they are not cures, and the damage caused by Alzheimer’s can only be slowed, not reversed. However, with early intervention, patients now have better chances of remaining independent and active in their relationships and interests. Ultimately, each new Alzheimer’s treatment buys patients and their loved ones more time and instills hope for a brighter future together.

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