Vulnerable Covid patients will be offered an antibody drug on the NHS from today to help them fight off the virus.
Xevudy, made by British pharmaceutical giant GlaxoSmithKline, was shown to slash the risk of hospitalisation and death from older strains by 79 per cent in clinical trials.
GSK says early lab results suggest it also offers high protection against the Omicron variant which has made other antibody therapies weaker.
Britain has ordered 100,000 doses of the drug, but questions have been raised whether this is enough given the incoming Omicron wave.
The Prime Minister’s spokesman was today unable to confirm whether they would buy more if needed.
It is the second treatment to be cleared for use on the NHS, after Regeneron’s monoclonal antibody drug Ronapreve was approved in August. It is already being rolled out in NHS hospitals.
Adding to the need to order more Xevudy, German researchers revealed today that Ronapreve — which was famously used to treat Donald Trump when he caught the virus last year — is ‘inefficient’ against Omicron.
However, they found Xevudy held up when exposed to mutant strain in lab experiments.
NHS chiefs say the treatment is suitable for around 1.3million of the most vulnerable patients in the UK, including organ transplant recipients and cancer patients.
The monoclonal antibody is given intravenously over 30 minutes, and must be administered within five days of an infection starting.
It works by binding to the virus spike protein — which it uses to invade cells — to slow down an infection.
But scientists say it will still be effective against Omicron because it binds to an area on the spike that has not mutated in the variant.
Professor Stephen Powis, NHS England’s medical director, said: ‘These new drugs have an important role to play.
‘If you test positive and are at high risk then we will be contacting you, and, if eligible you will be able to get access to these new treatments.’
Xevudy, a monoclonal antibody, will be available on the NHS from today. Health chiefs said it would be available to vulnerable patients such as organ transplant recipients or cancer patients
Monoclonal antibodies are manufactured in laboratories and work by mounting an immune response against the virus in people whose bodies are too weak to do it on their own.
It binds to the Covid spike protein — which it uses to invade cells — stopping the virus from sparking a serious infection.
The Prime Minister’s spokesman said today they had bought a ‘significant number’ of doses.
The Department for Health is yet to say whether there are plans to buy further doses.
NHS England will contact eligible patients over the coming weeks to let them know about the treatment.
They will then be sent a PCR test to use as soon as they start suffering symptoms of Covid.
If the result is positive, they will be invited to get a dose of Xevudy.
The NHS said the drug would form a ‘first line of defence’ against the virus.
The UK Medicines and Healthcare Regulatory Authority (MHRA) approved the treatment for patients at the start of this month.
It is administered over 30 minutes through an intravenous drip and works by binding to the Covid spike protein — which it uses to invade cells — and preventing it from multiplying in the body.
Preliminary tests found Ronapreve — already in use in the UK — was not as good at stopping infections with Omicron compared to other strains.
Separate testing of another monoclonal antibody manufactured by US-based company Eli Lilly also indicates it is less effective against the variant.
Vaccines are a country’s first line of defence against the virus.
But in cases where jabs do not trigger immunity in some patients, or the virus starts to get around jab-induced antibodies, then these drugs are the second line of defence.
Ronapreve is also available to patients on the NHS.
But the treatment is expensive costing around £2,000 per dose. It was famoulsy administered to Donald Trump when he was suffering from Covid.
And two groups of Germany based scientists separately found the Ronapreve drug won’t help in the fight against Omicron.
One team of Cologne-based researchers said: ‘The neutralizing activity of several monoclonal antibodies is strongly affected against the Omicron variant and will limit treatment options for Omicron-induced Covid.’
Meanwhile, another group of experts in Goettingen said Ronapreve was ‘inefficient’ in inhibiting the strain.
But both studies, which have not yet been peer reviewed, found Xevudy continued to work against Omicron.