An antibody therapy has been approved for the prevention and treatment of severe coronavirus complications in the UK.
The Medicines and Healthcare products Regulatory Agency (MHRA) – the government's independent advisory body – has signed off on the drug Ronapreve, developed by the pharmaceutical giants Regeneron and Roche.
Antibodies are infection-fighting proteins that are released by the immune system in response to a virus. Once the infection has passed, low levels of antibodies circulate in the bloodstream, helping to prevent the virus from taking hold again.
Ronapreve, used by President Trump when he caught the coronavirus in 2020, is comprised of manmade antibodies that act like the natural proteins in the body.
Injecting or infusing the antibodies causes them to bind to the coronavirus in the respiratory tract's lining, preventing the pathogen from gaining access to cells in the airways.
Data assessed by MHRA scientists reveal Ronapreve may prevent a coronavirus infection among at-risk individuals, hasten recovery of milder symptoms and reduce the likelihood of a patient being admitted to hospital with COVID-19 – the disease caused by the coronavirus.
One expert has hailed the approval "an important step forward", but stresses "many people get better of their own accord", with it being "hard to justify giving what are likely to be limited supplies of a relatively expensive treatment to huge numbers of people".
"We are pleased to announce the approval of another therapeutic treatment that can be used to help save lives and protect against COVID-19," said Dr Samantha Atkinson, from the MHRA.
Critically-ill coronavirus patients are commonly treated with the arthritis drug tocilizumab and the steroid dexamethasone, both of which target the individual's immune response rather than their infection itself.
The broad-spectrum anti-viral drug remdesivir is also being widely used, but is not COVID specific.
"Ronapreve is the first of its kind for the treatment of COVID-19 and after a meticulous assessment of the data by our expert scientists and clinicians, we are satisfied this treatment is safe and effective," said Dr Atkinson.
"With no compromises on quality, safety and efficacy, the public can trust the MHRA have conducted a robust and thorough assessment of all the available data."
Since the pandemic emerged, the MHRA has carried out a "rolling review", rapidly assessing promising drugs in the shortest possible time.
Starting in January, 2021, the agency has focused on the available data for Ronapreve. The MHRA has stressed, however, the drug's potential was assessed before widespread vaccination or the emergence of new coronavirus variants.
Interpretation of the trial results is therefore "now more complex". "It would be for the attending healthcare professional to make an informed decision" on whether Ronapreve is suitable for the individual, according to the MHRA.
"[Ronapreve] combines two antibodies that bind to different places on the coronavirus' spike protein, preventing uptake by cells and accelerating clearance of the virus," said Professor Martin Landray, from the University of Oxford.
"The rationale for combining two different antibodies is if a viral variant prevented one drug from binding to the spike protein, the other would still be effective, a 'belt and braces' approach."
The government and NHS are yet to confirm how Ronapreve will be used among patients. In the meantime, the MHRA is due to receive final study reports from Regeneron-Roche in the coming months.
"This licensing decision is an important step forward," said Professor Landray.
"There have been a number of trials in the out-of-hospital setting, each with positive results – reducing viral clearance and reducing the risk of hospitalisation. There have been no major safety concerns.
"The challenge going forward will be in determining which patients should be prioritised for this treatment.
"COVID is not a rare disease and many people get better of their own accord after a few days of a nasty flu-like illness. It would be hard to justify giving what are likely to be limited supplies of a relatively expensive treatment to huge numbers of people who are likely to get better on their own.
"On the other hand, it may play an important role in patients who are at higher risk of developing severe infection and who are more likely to end up in hospital."
Professor Penny Ward, from King's College London, added: "I think it is most likely to be used to prevent hospitalisation among people becoming sick with COVID who are at higher risk of needing hospital care [or] dying from disease.
"It might also be used to prevent COVID infections in people who are in contact with a confirmed COVID case and who might have reduced response to vaccination, for example people being treated for cancer.
"It can also be used to curtail outbreaks in institutions – care homes, hospitals, prisons, critical workplaces."
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Despite uncertainties around Ronapreve's use, Professor Ward added: "It's a good news day.
"Let now hope we can order and receive the supply we need to be able to use this effectively as we wait for the oral antivirals which are coming along the pike."
In a separate trial, called Recovery, Ronapreve was found to reduce the risk of death and shorten the hospital stay of patients who had not mounted their own immune response against the coronavirus. The MHRA is also due to receive further Recovery results.
Speaking of Ronapreve's approval, health secretary Sajid Javid added: "This is fantastic news from the independent medicines regulator and means the UK has approved its first therapeutic designed specifically for COVID-19.
"This treatment will be a significant addition to our armoury to tackle COVID-19, in addition to our world-renowned vaccination programme and life-saving therapeutics dexamethasone and tocilizumab.
"We are now working at pace with the NHS and expert clinicians to ensure this treatment can be rolled out to NHS patients as soon as possible."