A large study presented at the Alzheimer’s Association International Conference in Amsterdam and published in JAMA, suggests that treating Alzheimer’s patients very early in the disease process offers a better hope of slowing cognitive decline. The study focused on an experimental drug called donanemab, manufactured by Eli Lilly, which was found to modestly slow the progression of memory and thinking problems in the early stages of Alzheimer’s. The drug was observed to be most effective in patients at earlier stages and those under the age of 75.
According to the study, early-stage patients with lower levels of the protein tau, which forms tangles in the brain, experienced a decline in memory and thinking that was delayed by about four and a half to seven and a half months over an 18-month period compared to those taking a placebo. The study emphasized the importance of early diagnosis and intervention to manage the disease effectively.
Dr. Daniel Skovronsky, Eli Lilly’s chief medical and scientific officer, highlighted that intervening as early as possible allows for a greater impact on the disease before patients experience a rapid decline. The findings provide hope for more effective treatments for Alzheimer’s, a devastating disease affecting over six million Americans. The recent approval of another drug, Leqembi (also known as lecanemab), which also showed modest declines in early-stage Alzheimer’s, indicates a potentially promising direction in the search for effective medications.
However, both donanemab and Leqembi come with significant safety risks, such as brain swelling and bleeding, although the side effects are often mild. The study mentioned that more data are needed to determine if the benefits outweigh the potential harms of these drugs. It is important to note that neither Donanemab nor Leqembi reverses or repairs the brain damage caused by Alzheimer’s. They are considered only the first step in the quest for effective treatments.
The drugs target a protein called amyloid, which forms plaques in the brains of Alzheimer’s patients. Previous anti-amyloid drugs failed to demonstrate significant effects on memory or thinking problems. The approval of Aduhelm, another anti-amyloid drug, in 2021 generated controversy due to uncertainty about its effectiveness.
Donanemab and Leqembi are the first drugs to show clear evidence of slowing cognitive decline in the early stages of Alzheimer’s. However, some experts remain cautious about the modest effects of the drugs, questioning whether patients and families will notice a meaningful improvement. An intriguing aspect of the donanemab trial is that patients who reached a certain threshold of amyloid clearance stopped receiving the drug, yet their decline continued to slow.
It remains uncertain if the slowing decline will persist as amyloid levels rise again. The trial also revealed that patients with intermediate levels of tau experienced a greater slowing of decline compared to those with high tau levels. The trial included mainly white participants, which raised concerns about the lack of diversity in Alzheimer’s drug trials.
Despite the promising findings, the experience of a patient in the donanemab trial demonstrated the complexity of evaluating the drugs’ real-life impact. While the drug appeared to clear plaques, it was unclear if it slowed cognitive decline significantly. Overall, the study provides valuable insights into the potential benefits of early intervention in Alzheimer’s treatment. However, further research and data are needed to fully understand the drug’s efficacy and safety and its impact on patients’ daily lives.
