Gilead Sciences Inc’s remdesivir had no substantial effect on COVID-19 patients’ length of hospital stay or chances of survival, a clinical trial by the World Health Organisation (WHO) has found, the Financial Times reported on Thursday.

The antiviral drug, among the first to be used as a treatment for COVID-19, was one of the drugs recently used to treat US President Donald Trump’s coronavirus infection.

The FT report cites results from WHO’s Solidarity trial that evaluated effects of four potential drug regimens, including remdesivir, hydroxychloroquine, anti-HIV combination drug of lopinavir/ritonavir, and interferon, in 11 266 hospitalised patients.

The study found none of the treatments “substantially affected mortality” or reduced the need to ventilate patients, according to FT, which said it had seen a copy of the study. It also reported that the drugs had little effect on how long patients stayed in hospital.

Earlier this month, data from a US study of remdesivir by Gilead showed the treatment cut recovery time for COVID-19 patients by five days compared to placebo in a trial comprising 1 062 patients.

The WHO did not comment on the FT report, saying the results of its study were not yet public.

WHO chief scientist Soumya Swaminathan said on Wednesday that during the study, hydroxychloroquine and lopinavir/ritonavir were stopped in June after they proved ineffective, but other trials continued in more than 500 hospitals and 30 countries.

“We’re looking at what’s next. We’re looking at monoclonal anti-bodies, we’re looking at immunomodulators and some of the newer anti-viral drugs that have been developed in the last few months,” Swaminathan said.

Remdesivir received emergency use authorisation from the US Food and Drug Administration on May 1, and has since been authorised for use in several countries.

Gilead did not immediately respond to a Reuters request for comment.