Health Secretary Matt Hancock welcomed the discovery by researchers, thanking the scientists at the University of Oxford.
He said supplies of the drug have been stockpiled since March for use by the NHS.
In a video on Twitter, he said: “This is a huge step forward. And it’s because we backed the science, and because we’ve taken the approach that’s guided by the science, that we’ve been able to deliver this result.”
He added: “Now, because we spotted the early signs of the potential of dexamethasone, we’ve been stockpiling it since March. So we now have 200,000 courses that are ready to go.”
WATCH: Delighted to announce the first successful clinical trial for a life-saving #coronavirus treatment- reducing mortality by up to a third & further protecting our NHS
Peter Horby, professor of emerging infectious diseases in the Nuffield Department of Medicine, University of Oxford, and one of the chief investigators for the trial, described it as “an extremely welcome result”.
“This is the only drug that has so far shown to reduce mortality, and it reduces it significantly. It is a major breakthrough, I think,” he said.
“Dexamethasone is inexpensive, on the shelf, and can be used immediately to save lives worldwide.”
Martin Landray, professor of medicine and epidemiology at the Nuffield Department of Population Health, University of Oxford, was also one of the chief investigators.
He said: “COVID-19 is a global disease – it is fantastic that the first treatment demonstrated to reduce mortality is one that is instantly available and affordable worldwide.”
Prof Landray added: “It’s been around for probably 60 years.
“It costs in the order of £5, £5 for a complete course of treatment in the NHS, and substantially less – probably less than one dollar – in other parts of the world, for example in India.”
Prof Horby said: “The survival benefit is clear and large in those patients who are sick enough to require oxygen treatment, so dexamethasone should now become standard of care in these patients.”
Prof Landray said: “What we can see is the biggest benefits in those people at the biggest risks, which I guess if you wanted to design a drug is exactly how you’d hope to have the results.”
The researchers warn that the steroid has not been studied in patients in the community, and people should not be taking dexamethasone for COVID-19.
It is particularly exciting as this is an inexpensive, widely available medicine
Professor Stephen Powis, NHS England medical director, said: “This is a huge breakthrough in our search for new ways to successfully treat patients with COVID, both in the UK and across the world.
“It is thanks to NHS staff and patients who participated in the trial that from now, we are able to use this drug to dramatically improve COVID-19 survival for people in hospital who require oxygen or ventilation.”
The government’s chief scientific adviser Sir Patrick Vallance said: “This is tremendous news today from the RECOVERY trial showing that dexamethasone is the first drug to reduce mortality from COVID-19.
“It is particularly exciting as this is an inexpensive, widely available medicine.
“This is a groundbreaking development in our fight against the disease, and the speed at which researchers have progressed finding an effective treatment is truly remarkable.”
This is the most important trial result for COVID-19 so far. Significiant reduction in mortality in those requiring oxygen or ventilation from a widely available, safe and well known drug. Many thanks to those who took part and made it happen. It will save lives around the world. https://t.co/zRIaHulHOe
England’s chief medical officer Professor Chris Whitty said it was “the most important trial result for COVID-19 so far” and “will save lives around the world”.
According to a government list of medicines that cannot be exported from the UK or hoarded, dexamethasone was banned for export in tablet form on 24 April, and as an oral solution or for injection on 16 June.
Alexander is the Online Editor at BBC Science Focus and is the one that keeps sciencefocus.com looking shipshape and Bristol fashion. He has been toying around with news, technology and science on internet for well over a decade, and sports a very fetching beard.