The fight against dementia is entering a transformative phase with the advent of disease-modifying drugs and a growing understanding of Alzheimer's biology. Scientific advancements are paving the way for treatments that could significantly alter the course of the disease, even in resource-limited settings.
New Drugs on the Horizon
In 2024, the first drugs capable of changing the trajectory of Alzheimer's disease, such as Eisai and Biogen's lecanemab (Leqembi) and Eli Lilly's donanemab (Kisunla), gained approval in several Western countries. These monoclonal antibodies represent a significant improvement over previous treatments that only addressed symptoms.
Jeff Cummings, professor of brain science and health at the University of Nevada, expressed his enthusiasm, stating, "We are truly in a new era. We have opened the door to understanding and manipulating the biology of Alzheimer's disease for the benefit of our patients."
Lecanemab and donanemab work by prompting the body to remove amyloid plaques in the brain, slowing cognitive decline by about 30%. However, these drugs require bi-weekly or monthly infusions in a medical setting, advanced technology for patient monitoring, and come with a high price tag, limiting their accessibility.
Overcoming Challenges and Expanding Access
Currently, lecanemab is priced between £20,000 to £25,000 a year for each patient, not including the cost of additional tests and scans. These challenges highlight the need for more affordable and accessible diagnostic and treatment options.
Recent decisions by the FDA to allow Alzheimer's diagnosis based on blood tests for enrollment in drug trials could pave the way for broader use of these tests in clinics, replacing expensive scans. Furthermore, research suggests that these drugs could potentially be administered via subcutaneous injection, enabling at-home administration.
The Promise of Combination Therapies
Experts are exploring combination therapies, drawing parallels to successful treatment protocols for leukemia and AIDS. This approach involves using drugs like lecanemab to eliminate amyloid plaques, alongside anti-inflammatories or medications that block β-secretase, the enzyme that produces amyloids.
Cummings, who is chairing trials for a tablet form of semaglutide (Ozempic), anticipates results in late 2025. He suggests that semaglutide could be effective in reducing inflammation, a fundamental aspect of Alzheimer's disease.
Focus on Early Detection and Prevention
The ability to slow disease progression in early-stage patients underscores the importance of early detection. A donanemab study of pre-symptomatic patients with genetic markers or PET scan abnormalities is underway, signaling a shift towards preventive treatments.
Experts believe that up to 40% of Alzheimer's cases could be prevented by addressing key risk factors such as smoking, alcohol consumption, and air pollution. Paola Barbarino, chief executive of Alzheimer's Disease International (ADI), emphasized the need for increased awareness and resources in low- and middle-income countries, where dementia is often underrecognized.
While a complete cure for Alzheimer's remains elusive, Cummings remains optimistic: "We know enough about manipulating the biology and how it starts that we can... control the processes that start the illness, and therefore it simply wouldn't develop in the brain."
