The last drug for Alzheimer's was licensed in the UK in the 20th century. Huge improvements have been made in our understanding of the disease. We may be on the verge of new treatments that could have an impact on some of the fundamental brain changes that are thought to lead to dementia. The results of a long-awaited trial of a promising new drug were published in the New England Journal of Medicine. There are some benefits for Alzheimer's sufferers.
Alzheimer's disease is a type of cognitive impairment that affects a person's normal activities. It's the leading cause of death in the UK. The cost to care for people with dementia is more than £25 billion a year. The number of people will increase as they get older. Estimates show that 1.6 million people in the UK will be affected by dementia by the year 2020.
Alzheimer's is the most common cause of dementia and accounts for about two-thirds of cases. The disease is related to the abnormal build up of two proteins in the brain, which are deposited outside nerve cells. Brain cell death and alterations in brain chemistry are thought to be caused by inflammation and the build up of theamyloid in the brain. People experience progressive impairment of their day-to-day memory and other cognitive functions as a result of this. It takes six to seven years after a diagnosis for dependence and death to occur.
Brain scans, spinal fluid examination, and blood tests are some of the methods that can be used to detect the disease. Around 20% of 70 year olds have brain beta-amyloid deposition, which is caused by the build-up of thisProtein, 20 years before symptoms occur. The long, pre-symptomatic period is seen by some scientists as an opportunity to prevent the start of cognitive decline.
A key target for drug development is believed to be the role that theamyloid plays in Alzheimer's. In 1999, a paper in the journal Nature reported that a vaccine could be used to remove Alzheimer's disease from mice. Similar approaches have been tried in humans. These attempts have been hampered by depressing failures. Multiple drugs failed to show clinical effects and were complicated by side effects. One drug, aducanumab, was controversially licensed in the US last year, although questions remain over whether the drug affects cognitive abilities, and it hasn't been licensed in Europe.
In patients with early Alzheimer's disease, lecanemab slowed cognitive decline by 27% over 18 months. While the trial duration was too short to know for certain, changes in other disease markers suggest that removing theamyloid may slow down other pathological processes as well. The approval of the drug in the US and Europe is expected before the end of the year. Eli Lilly's donanemab is expected to be the next drug to be tested.
Drugs that have an impact on key biological processes and produce at least some beneficial effects on cognitive function is a remarkable achievement. If we could identify and treat individuals who might benefit before symptoms start, Alzheimer's could be treated and even prevented. There are important things to keep in mind. There is debate about whether the effects of lecanemab will have a benefit for patients.
Longer-term followup is important if the drug slows the disease process. Benefits need to be balanced against risk. Almost a quarter of patients who were treated with lecanemab had some mild changes on their magnetic resonance images. There were no excess deaths reported when lecanemab was used with blood thinners or clot- busting treatments.
The National Health Service or most other healthcare systems are not prepared to deliver these drugs. The wider National Health Service doesn't have the infrastructure or staff to diagnose potentially eligible patients. The National Health Service doesn't routinely offerPET scans that can detectamyloid Many clinics don't have the ability to deliver the drug or perform multiple safety scans. It is not certain that a drug will meet the Nice evaluation of cost-effectiveness.
This is the road we have been on before. When their benefits became clear, stroke services were transformed into emergency "clot- busting" therapies. Patients with cancer are already diagnosed with the disease. Many of the immunotherapies that need intensive monitoring for potentially dangerous side-effects are used in the National Health Service.
If lecanemab is licensed in the UK it will be a major breakthrough. Cancer and cardiovascular disease get more funding than dementia. No single drug will be a panacea. Multiple different treatment approaches will likely be needed for cancer, HIV and heart disease. Three-quarters of the drugs in more than 170 ongoing trials in Alzheimer's worldwide are targeting other aspects of the disease.
When new treatments become available, we need to prepare for a time when the pressures on the health service are not as great. We need to provide better care for our patients now and prepare them for the future. With an Alzheimer's epidemic looming, we cannot ignore this challenge.