It is the second monoclonal antibody therapeutic to receive approval in the UK, three months after Ronapreve, which is produced by Regeneron/Roche, became the first.
The MHRA recommends that sotrovimab should be given within five days of symptoms developing, as it is proven to be most effective in the early stages of infection.
The regulator said it can be used to treat people with mild or moderate Covid-19 who are at risk of developing a severe infection because of factors like old age, obesity or heart disease.
Sotrovimab is administered to patients intravenously over a 30-minute period.
Announcing the drug’s approval, Dr June Raine, the chief executive of the MHRA, said: “I am pleased to say that we now have another safe and effective Covid-19 treatment, Xevudy (sotrovimab), for those at risk of developing severe illness.
“This is yet another therapeutic that has been shown to be effective at protecting those most vulnerable to Covid-19, and signals another significant step forward in our fight against this devastating disease.”
Professor Sir Munir Pirmohamed, who chairs the Commission on Human Medicines, said his organisation assessed the drug independently and agreed with the MHRA’s decision.
“Based on the data reviewed by the Commission and its expert group, it is clear sotrovimab is another safe and effective treatment to help us in our fight against Covid-19,” he said.
It is not yet known whether sotrovimab could be adversely affected by the omicron variant. The MHRA is working with its manufacturers to establish whether the new strain reduces its efficacy.
The treatment targets the Covid virus’ spike protein, which it uses to bind to host cells and gain entry.
Although a complete picture of the latest variant of concern is still several weeks away, omicron is known to have more than 30 mutations on its spike protein, raising the possibility that it could evade vaccines and antibody treatments.
For this reason, scientists have expressed fears that treatments like Ronapreve and Xevudy are likely to be impacted by the omicron Covid variant.
“These monoclonal antibodies are likely to be less effective. I think that’s a big issue,” Professor Lawrence Young, a virologist at the University of Warwick, said earlier this week.
Since the emergence of the new variant, countries have rushed to impose travel restrictions to and from southern Africa, where it was first detected. However, many nations, including the UK, Nigeria and South Korea, have already identified their first omicron cases.