By Deena Beasley

(Reuters) – Gilead Sciences Inc, which has suggested that a shorter treatment duration could extend limited supplies of its drug remdesivir, on Wednesday published results of a study showing no significant difference in outcomes between 5- and 10-day courses of the drug for patients with severe COVID-19.

Gilead announced “top-line” findings from the trial on April 29. The full results were published in the New England Journal of Medicine.

Gilead’s trial involved 397 patients hospitalized with severe COVID-19, most of whom were not on ventilators. The company said the study, which did not include a placebo comparison, showed that 14 days after treatment with the intravenous drug, 64% of patients treated for 5 days and 54% treated for 10 days showed some clinical improvement.

At the 14-day mark, 8% of patients in the 5-day group and 11% of patients in the 10-day group had died.

Gilead said the results should not be interpreted as indicating that the shorter duration worked better since evidence of improved outcomes occurred early on, leading investigators to attribute the difference to imbalances inpatient status at enrollment.

Adverse events included nausea and worsening respiratory failure. The company said 2.5% of patients in the 5-day group and 3.6% in the 10-day group discontinued treatment due to elevated liver enzymes.

The U.S. Food and Drug Administration granted emergency use authorization to remdesivir on May 1, citing results from a different study run by the National Institutes of Health showing that the drug reduced hospitalization stays by 31% compared to a placebo treatment.

Gilead has said it anticipates results from a company study of remdesivir in patients with more moderate COVID-19 around the end of this month.

Gilead has pledged to donate 1.5 million doses of remdesivir – or enough to treat at least 140,000 patients – to fight the global pandemic.

(Reporting By Deena Beasley; Editing by Sonya Hepinstall)