A plain language update on developments in drug treatments.
Alzheimer's disease is a condition that will affect78 million people by 2030. It has been tirelessly explored by researchers searching for new avenues for effective treatments. Clinical trials are currently testing 141 drugs in Alzheimer’s disease treatment, 3 of which show promising results.
Among the emerging breakthroughs, a drug named Lecanemab (Leqembi®) developed by the pharmaceutical company Eisai was fully approved by the US Food and Drug Administration (FDA) as a treatment for patients with early Alzheimer’s disease on July 6 2023, with an annual treatment cost of just over $26,000 US per patient.
Lecanemab, is an antibody that removes amyloid plaques in the brain, a hallmark of Alzheimer's disease. Clinical trial results showed that lecanemab removed amyloid and tau proteins in the brains of patients with early Alzheimer’s disease. In these patients, cognitive decline in thinking and memory skills were slowed by 27% and decline in quality of life was slowed by 56%.
Donanemab is another drug that removes amyloid plaques in the brain developed by the pharmaceutical company Eli Lilly. It is currently pending FDA approval as a treatment for Alzheimer’s disease. Clinical trial results showed that donanemab slowed cognitive decline by 35% compared to placebo (which equates to the slowing of disease progression by 4-7 months), and also showed 40% less decline on the ability to perform activities of daily living
Both lecanemab and donanemab have reported adverse effects that include brain swelling and brain bleeds. These drugs are also delivered by an intravenous drip. This requires patients to visit a clinic in person and receive the medicine that can take up to an hour.
Remternetug is another promising amyloid targeting drug made by Eli Lilly. It is also meant for patients with early-stage Alzheimer’s disease and is referred to as a second-generation immunotherapy since it targets the same type of amyloid as donanemab, however it is anticipated to perform better. A current phase 3 trial will compare a different method using injections under the skin to see if it is more effective in reducing adverse effects and if it offers a more practical way of drug delivery.
Although the treatments listed above target amyloid, there are other drugs being researched and developed in the Alzheimer’s disease drug development pipeline. Some examples include stem cell therapies, repurposed agents, vaccines, disease-modifying small molecules that we may hear more about. This may lead to potential therapeutics targeting different pathway getting approved for use in the future.