The World Health Organization (WHO) said on Saturday that it was discontinuing its trials of the malaria drug hydroxychloroquine and combination HIV drug lopinavir/ritonavir in hospitalised patients with COVID-19 after they failed to reduce mortality.

"These interim trial results show that hydroxychloroquine and lopinavir/ritonavir produce little or no reduction in the mortality of hospitalised COVID-19 patients when compared to standard of care. Solidarity trial investigators will interrupt the trials with immediate effect," the WHO said in a statement, referring to large multi-country trials that the agency is leading.

The U.N. agency said that the decision, taken on the recommendation of the trial's international steering committee, does not affect other studies where the drugs are used for non-hospitalised patients or as a prophylaxis.

Another arm of the WHO-led trial is looking at the potential effect of Gilead's antiviral drug remdesivir on COVID-19.