Drug regimens containing remdesivir, hydroxychloroquine, lopinavir/ritonavir, and interferon have "little or no effect" on the 28-day mortality or the course of illness in hospitalised Covid-19 patients, the World Health Organization said on Friday, announcing the interim results of the global trial.
Remdesivir is the only antiviral drug that has been authorized for treatment of Covid-19 patients in the US.
The drug's manufacturer Gilead rejected the findings of the trial. Adults hospitalized with COVID-19 who did not receive any study drug, had no known contraindications to any study drug, with no transfer anticipated within 72 hours were eligible.
The Solidarity Trial is the world's largest randomized controlled trial of Covid-19 therapeutics, involving nearly 13,000 patients in 500 hospitals in 30 countries.
Dexamethasone, a low-priced steroid now widely used on Covid patients in intensive care in the United Kingdom, was not included in this study.
The study looked at how each of these treatments affected mortality, ventilator use, and length of hospital stay in patients that were hospitalized with COVID-19. But the other trials continued as planned.
Remdesivir, originally developed to treat Ebola, has been in demand for Covid since a US government trial showed it reduced patients' recovery time by four days.
What has the reaction been?
The logo of Gilead Sciences Inc is pictured during a news conference in New Delhi.
Gilead, which quickly repurposed what it had developed as an Ebola drug when the Covid-19 pandemic began, said that other, smaller remdesivir trials showed the treatment cut Covid-19 recovery time by five days and helped reduce the risk of death in some patients who were getting oxygen.
"We are concerned that the data from this open-label global trial have not undergone the rigorous review required to allow for constructive scientific discussion, particularly given the limitations of the trial design", the company said.
Gilead previously ran its own clinical trials on the drug, and found that 65% of moderately ill patients had improvement after 11 days.
Women are more likely than men to consider COVID-19 a serious problem and to agree and comply with restrictions like staying home and wearing masks, according to a survey in March/April of more than 21,000 people in eight wealthy countries.
"It is not a rare disease". We need scalable, affordable and equitable treatments.
"When adding Solidarity to the trials we have to date, I think it is likely that a large mortality benefit does not exist, and in this context, the cost is too high", he said.
A few of these drugs had been given emergency-use authorization by governments of many countries, which means patients hospitalized with COVID-19 could be treated with the drug - local laws and supply permitting. President Donald Trump took Remdesivir when he was recovering from the virus earlier this month, among other treatments. Only an old steroid - dexamethasone - has proven life-saving.
What about other Covid treatments?
The WHO-led researchers say their trial, called the Solidarity trial, will continue.
The study plans to conduct a trial on novel antiviral drugs, immunomodulators and anti-SARS COV-2 monoclonal antibodies.
However the researchers said it was not possible to say whether the antibody responses induced by the vaccine were sufficient to protect from infection because the trial was not created to assess its efficacy.
The potential vaccine, dubbed BBIBP-CorV, is being developed by the Beijing Institute of Biological Products, a subsidiary of China National Biotec Group (CNBG).