Brits at risk of Alzheimer's will miss out on a 'miracle' drug to treat the incurable disease on the NHS, health chiefs today announced. 

Lecanemab has been proven to slow the progress of the memory-robbing illness in its early stages. 

It was today approved by medicines regulator, the Medicines and Healthcare products Regulatory Agency (MHRA). 

But draft guidance by the UK's drugs watchdog ruled the benefits of the drug, estimated to cost the NHS up to £1billion per year, 'are too small to justify the costs'. 

It means lecanemab will only be available to Brits who could pay around £20,000 privately every year.   

Campaigners and charities today labelled the decision 'bittersweet' and 'deeply disappointing'. However, experts also pointed to a 'lack of evidence' over its long-term side effects. 

It is estimated around 70,000 adults in England would have been eligible for treatment with lecanemab if approved for use on the health service. 

The drug has been proven to slow progression of the disease by as much as 27 per cent in trials by helping to remove the build up of the harmful protein amyloid in the brains of people with early-stage Alzheimer's.   

Known as an amyloid immunotherapy, it is thought that these proteins interfere with messages sent between different parts of the brain, resulting in the memory and independence robbing symptoms. 

Experts have long believed  it could herald a new era of dementia treatment by tackling the cause rather than just alleviating symptoms. 

The drug has already been given the green light in the US, China, Japan, Hong Kong, South Korea and Israel. 

No price for the drug has been publicly announced in the UK. In the US the treatment costs £20,000 a year. 

But it was rejected by EU medicines regulator the European Medicines Authority last month, due to concerns over side effects such as 'swelling' and 'potential bleedings in the brain'.

It is now the first medicine to be licensed in the UK that has been shown to slow down progression of the disease, by between 4 and 6 months, the National Institute for Health and Care Excellence (Nice)'s independent committee heard. 

However, it added, there was a significant cost to the treatment including intensive monitoring for side-effects and fortnightly trips to hospital for patients. 

Previously, the only available drugs for Alzheimer's in the UK were to treat symptoms. 

Julian Beach, the interim executive director of healthcare quality and access at the MHRA, said: 'We're assured that, together with the conditions of the licence approval, the appropriate regulatory standards for this medicine have been met.

'As with all medical products, we will keep its safety under close review, and with a controlled post-authorisation safety study to be undertaken, we will ensure that the benefit risk of lecanemab in clinical use is closely followed up.'

Dr Samantha Roberts, chief executive of NICE, however, added: 'This is a new and emerging field of medicine which will no doubt develop rapidly. 

'However, the reality is that the benefits this first treatment provides are just too small to justify the significant cost to the NHS. 

'It is an intensive treatment to give to patients involving a hospital visit every two weeks with skilled staff needed to monitor them for signs of serious side effects, plus the cost of purchasing the drug.

'Our independent committee has rigorously evaluated the available evidence, including the benefit for carers but NICE must only recommend treatments that offer good value to the taxpayer.'

Meanwhile, Tara Spires-Jones, professor of the UK Dementia Research Institute at the University of Edinburgh, said the arrival of the drug marked 'a turning point' but cautioned that it could be accompanied by 'dangerous side-effects'.

Speaking on BBC Radio 4’s Today programme, she said: 'It’s the first time we've actually been able to slow disease progression at all. So from that standpoint, it's amazing.

'However, the treatment’s not perfect. It only slows disease progression moderately, and it comes with dangerous side-effects, and people really do need to be monitored very carefully, and only certain people will be able to use the drug. 

'So together, it’s great news, but we have to temper our enthusiasm.'

She added: 'Some people who take this drug have brain swelling and bleeding and a few people have died from those side-effects.'

But charities and campaigners today labelled NICE's decision 'deeply disappointing' and urged the Government to 'find a solution' to prevent Brits with dementia from missing out. 

Hilary Evans-Newton, chief executive at Alzheimer's Research UK, said: 'Today's news is bittersweet for people affected by Alzheimer's disease. 

'It's a remarkable achievement that science is now delivering licensed treatments that can slow down the devastating effects of Alzheimer's, rather than just alleviating its symptoms. 

'However, it's clear our health system isn't ready to embrace this new wave of Alzheimer's drugs. 

'It means that, as things stand, people in the early stages of the disease will be denied access to lecanemab through the NHS, and it will only be available to those who can pay privately. This is deeply disappointing.'

She added: 'Of course, like first-generation treatments for other diseases, lecanemab has modest benefits and side effects that need careful monitoring.

'It's not a cure, but it is a real step forward — the first new dementia medicine to be licensed in more than 20 years.

'Further negotiations between NICE, Eisai and the NHS may offer a way forward.   

'But the heartbreaking reality is that those who could benefit from drugs like lecanemab don't have time to wait. 

'We've written to the Health Secretary Wes Streeting urging him to act, and to find a solution so that people with dementia in the UK don't continue to miss out on innovative treatments. 

'Lecanemab represents the beginning of a sea-change in how diseases like Alzheimer's will be treated in future. 

'There are now more than 160 trials underway testing over 125 experimental treatments for Alzheimer's across the globe, including 30 in late-stage trials. 

'Despite today's frustrating news, it really is a matter of when, not if, new treatments become available.'

Meanwhile, Fiona Carragher, chief policy and research officer at the Alzheimer’s Society, said: 'While we welcome the MHRA approval, it is disappointing that NICE has not recommended approving lecanemab for use on the NHS at this stage. 

'The news that lecanemab will be restricted to certain groups of patients will also lead to uncertainty for many people with Alzheimer's disease and their loved ones.

'We respect the decisions regulators have made, however we know these announcements will bring a mix of emotions for those who have been waiting a long time since the promising trial results were first announced.

'The NICE recommendation reflects the urgent challenges which must be addressed regarding how we diagnose and treat people with dementia.'

It comes as, it was revealed in April that around 5,000 Brits could get cheap blood tests to spot Alzheimer's in efforts to revolutionise 'shocking' NHS diagnostic rates.

Under two landmark trials, researchers from Oxford and University College London are set to use tests to detect proteins in the blood linked to the disease. 

At the time, researchers said they hoped the 'groundbreaking' blood test, which costs around £100, could speed up the process, allowing patients to get treated earlier. 

The trials, which are expected to cost about £10million, are set to take place across the UK and will be carried out with people who have reported symptoms to their GP and who may be in the early stages of dementia. 

A report published earlier this year by NHS England said 'timely diagnosis of dementia is vital', adding new blood tests could soon replace lumbar punctures in diagnosing the disease. 

Around 944,000 in the UK are thought to be living with dementia, while the figure is thought to be around 7million in the US.

Alzheimer's affects around six in 10 people with dementia.

It is thought to be caused by a build-up of amyloid and tau in the brain, which clump together and from plaques and tangles that make it harder for the brain to work properly.

Eventually, the brain struggles to cope with this damage and dementia symptoms develop.

Memory problems, thinking and reasoning difficulties and language problems are common early symptoms of the condition, which then worsen over time.

Dementia are expected to sky-rocket in the coming years, making a cheap screening tool vital to get to grips with the challenge.

Alzheimer's Research UK analysis found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier, making it the country's biggest killer.