Researchers in England say they have the first evidence that a drug can improve COVID-19 survival — a steroid called dexamethasone reduced deaths by up to one third in severely ill hospitalised patients.

Low doses of the steroid dexamethasone can reduce deaths by one-third in ventilated COVID-19 patients, according to researchers who assessed the performance of the inexpensive drug in more than 2,100 patients.

Results were announced on Tuesday and researchers said they would publish them soon. The study is a large, strict test that randomly assigned 2,104 patients to get the drug and compared them with 4,321 patients getting only usual care.

The analysis is part of the RECOVERY (Randomised Evaluation of COVID-19 Therapy) trial, which was established to test a range of potential therapies for COVID-19, including low-dose dexamethasone — a steroid treatment.

This is the same study that earlier this month showed the malaria drug hydroxychloroquine was not working against the coronavirus.

The drug was given either orally or through an IV. It reduced deaths by 35 per cent in patients who needed treatment with breathing machines and by 20 per cent in those only needing supplemental oxygen. It did not appear to help lesser ill patients.

The RECOVERY trial included over 11,500 patients, enrolled from more than 175 hospitals in the UK, noted a statement by the University of Oxford.

In the trial, a total of 2,104 patients were randomised to receive dexamethasone 6 milligrams once per day — either by mouth or by intravenous injection — for ten days, and were compared with 4321 patients randomised to usual care alone.

Among the patients who received usual care alone, mortality was highest in those who required ventilation (41 per cent), intermediate in those patients who required oxygen only (25 per cent), and lowest among those who did not require any respiratory intervention (13 per cent), the scientists said.

They found that dexamethasone reduced deaths by one-third in ventilated patients and by one fifth in other patients receiving oxygen only.

However, the researchers said there was no benefit from dexamethasone among the patients who did not require respiratory support.

Based on these results, the scientists believe that the drug could prevent nearly one death in the treatment of around eight ventilated patients, or around 25 patients requiring oxygen alone.

“Dexamethasone is the first drug to be shown to improve survival in COVID-19. This is an extremely welcome result,” said Peter Horby, one of the chief investigators of the trial from the University of Oxford in the UK.

“This is an extremely welcome result. 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. 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,” Horby added.

The drug, according to the scientists, is inexpensive, on the shelf, and can be used immediately to save lives worldwide.

“These preliminary results from the RECOVERY trial are very clear — dexamethasone reduces the risk of death among patients with severe respiratory complications,” said Martin Landray, another chief investigator of the trial from the University of Oxford.

The study enrolled more than 11,000 patients in England, Scotland, Wales and Northern Ireland who were given either standard of care or that plus one of several treatments: the HIV combo drug lopinavir-ritonavir, the antibiotic azithromycin; the steroid dexamethasone, the anti-inflammatory drug tocilizumab, or plasma from people who have recovered from COVID-19 that contains antibodies to fight the virus.

“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,” Landray added.

Research is continuing on the other treatments. The research is funded by government health agencies in the United Kingdom and private donors, including the Bill and Melinda Gates Foundation.