For decades, frustrated neurologists had nothing but palliative care to offer as the grey matter covering the brain — which is responsible for processing thoughts and many of the higher functions, such as memory — degenerated progressively in patients with Alzheimer’s disease. First identified in 1906, the cognitive disorder has been one of the most difficult challenges for healthcare systems globally. The failure rate of drugs to combat it is 99.6 per cent — for cancer, this rate is around 81 per cent. That’s why the result of clinical trials of lecanemab, a new drug developed by pharma companies Biogen and Eisai, has generated hope. On Tuesday, the two companies announced that the drug slowed down the rate of memory and thinking decline in early-stage Alzheimer’s patients by 27 per cent. This might seem a modest rate but this is the first time a drug has shown the potential to slow down the onset of dementia.
Lecanemab is an antibody that cleans protein deposits on brain cells, believed by a section of scientists to cause cognitive impairments. Known as the “amyloid hypothesis,” their thesis holds that clumps of the protein beta-amyloid accumulate in toxic proportions as the disease progresses. The thesis has been a graveyard for Alzheimer’s drug research in the past. In clinical trials, several drugs have shown the ability to reduce the plaque build-up caused by the protein but they have failed to alter the trajectory of dementia in patients, leading several experts to question the amyloid hypothesis. Last year, another anti-amyloid drug developed by Biogen failed after being approved by the US Food and Drug Administration. Not only did lecanemab clear the amyloid build-up in the brain cells of participants in the 18-month long trial, it also demonstrated a significant effect on their cognitive functions.
More than 50 million people have Alzheimer’s worldwide. In the past 20 years, mortality caused by the disease has shot up by more than 120 per cent. Experts believe that these figures do not depict the true extent of the healthcare problem. In many parts of the world, dementia is seen as a fallout of the ageing process and people do not seek medical care. But research has shown that in a large number of cases, the illness begins in the mid to late forties. That’s why drug candidates like lecanemab that target early-stage patients could hold the key in the battle against Alzheimer’s. For that, pharma research must be accompanied by addressing two other imperatives: Increasing awareness about the disease and making the new medicines accessible to all.