The drugs -- artesunate, imatinib and infliximab -- were selected by an independent expert panel for their potential in reducing the risk of death in hospitalised Covid-19 patients, the WHO said in a statement. 

The drugs are already in use for other conditions: artesunate is used for severe malaria, imatinib for certain cancers, and infliximab for diseases of the immune system such as Crohn's Disease and rheumatoid arthritis. 

"Finding more effective and accessible therapeutics for Covid-19 patients remains a critical need, and WHO is proud to lead this global effort," WHO Director General, Dr Tedros Adhanom Ghebreyesus, said in the statement. 

"I would like to thank the participating governments, pharmaceutical companies, hospitals, clinicians and patients, who have come together to do this in true global solidarity," he added. 

The trial involves thousands of researchers in over 600 hospitals in 52 countries. Artesunate will be administered to Covid-19 patients intravenously for seven days, imatinib will be given once daily for 14 days, and infliximab will be injected in one single dose. 

The drugs' manufacturers, Ipca (artesunate), Novartis (imatinib) and Johnson & Johnson (infliximab) donated supplies to the trial, the WHO said. 

None of the drugs are currently approved by the US Food and Drug Administration for use in coronavirus patients. 

A WHO-led trial, last year, evaluated four drugs -- remdesivir, hydroxychloroquine, lopinavir and interferon. The results showed that the drugs had little or no effect on hospitalised patients with Covid-19.