Gilead Sciences, a biopharmaceutical company in the US, on Wednesday, announced “positive data” in the clinical trial of remdesivir, an experimental antiviral drug, for the treatment of COVID-19.

Remdesivir was originally developed by the company as a potential treatment for Ebola, but it failed.

According to the company, the drug was found to be effective on COVID-19 patients during the trial which began in February.

Gilead Sciences said it administered the drug on 397 severely ill COVID-19 patients and more than half of them were discharged within two weeks.

Aruna Subramanian, a Stanford University infectious diseases professor who led the study, said the patients showed improvement after the treatment.

“These data are encouraging as they indicate that patients who received a shorter, 5-day course of remdesivir experienced similar clinical improvement as patients who received a 10-day treatment course,” Subramanian said.

The company said it will report the outcome of the first 600 patients in the clinical trial by the end of May.

It added that the clinical trial will also be done in the UK, China, France, Germany, Hong Kong, Italy, Japan Korea, the Netherlands, Singapore, Spain, Sweden, Switzerland and Taiwan.

Pfizer, an American biopharmaceutical company, on Tuesday, said its COVID-19 vaccine could be ready for emergency use by September.

The World Health Organisation (WHO) said there are about 20 different potential COVID-19 vaccines currently being developed.