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Alzheimer's drugs show limited impact, study finds
A comprehensive review by the Cochrane Collaboration has cast doubt on the effectiveness of recently developed Alzheimer's drugs, concluding their benefits fall short of meaningful improvements for patients. The analysis, which examined 17 clinical trials involving over 20,000 participants, found that while these medications can slow cognitive decline, the effect is minimal and accompanied by significant risks.
How the drugs work
The treatments in question, including donanemab and lecanemab, target beta amyloid-a sticky protein that accumulates between brain cells in Alzheimer's patients. Engineered antibodies are designed to identify and clear amyloid from the brain, a strategy that had previously failed in earlier trials. However, recent studies suggested these newer drugs could modestly slow the progression of cognitive deterioration, marking a historic first in Alzheimer's treatment.
Safety concerns and high costs
Despite their potential, the drugs carry risks of brain swelling and bleeding, requiring frequent administration every two to four weeks. The financial burden is also substantial, with an 18-month private treatment course costing approximately £90,000-far beyond the reach of most patients. Currently, the NHS does not fund these medications, leaving them accessible only to those who can afford private care.
Expert perspectives diverge
Professor Edo Richard, a neurologist at Radboud University Medical Centre and a co-author of the Cochrane report, emphasized the limited benefits in clinical practice. "I would tell my patients they are unlikely to experience meaningful improvements from these drugs," he said. "They impose a significant burden on patients and their families, and it's crucial to be transparent about what they can realistically expect."
Richard also highlighted the need to explore alternative approaches, such as targeting brain inflammation, to develop more effective treatments for Alzheimer's.
"It's extremely important that we're honest with patients about what they can expect. I'm always wary of giving people false hope."
Prof Edo Richard, Radboud University Medical Centre
Backlash from the scientific community
The Cochrane review has sparked intense debate, with some experts criticizing its methodology. Critics argue that grouping older, less effective drugs with newer, more promising treatments oversimplifies the analysis and undermines the progress made in recent trials.
Professor Bart De Strooper of the UK Dementia Research Institute at UCL described the review as "fundamentally flawed," stating it "blurs the evidence rather than clarifying it." He emphasized that while early amyloid-targeting drugs failed, newer antibodies have demonstrated modest but real clinical benefits.
Dr. Richard Oakley from the Alzheimer's Society urged caution in interpreting the findings, warning against dismissing decades of scientific progress. "It's essential to approach this review with nuance," he said. "We must avoid oversimplifying the complexities of Alzheimer's research."
NHS review underway
The National Institute for Health and Care Excellence (NICE), which determines NHS funding for medications, has previously rejected these drugs. However, it is currently reassessing the evidence, taking into account the impact on unpaid carers and the broader implications for patient care.
