On Jun. 1, 2020, Gilead Sciences announced topline results from the Phase 3 SIMPLE trial in hospitalized patients with moderate COVID-19 pneumonia. This open-label study evaluated 5-day and 10-day courses of the investigational antiviral remdesivir plus standard of care, versus standard of care alone.

The study demonstrated that patients in the 5-day remdesivir treatment group were 65 percent more likely to have clinical improvement at Day 11 compared with those in the standard of care group. The odds of improvement in clinical status with the 10-day treatment course of remdesivir versus standard of care were also favorable, trending toward but not reaching statistical significance.

Remdesivir is currently approved in Japan as a treatment for patients infected with SARS-CoV-2, the virus that causes COVID-19. Outside of Japan, remdesivir is an investigational, unapproved drug. The U.S. Food and Drug Administration (FDA) granted remdesivir an Emergency Use Authorization for the treatment of hospitalized patients with severe COVID-19; the authorization is temporary and does not take the place of the formal new drug application submission, review and approval process.

In this study, hospitalized patients with confirmed COVID-19 infection and evidence of pneumonia without reduced oxygen levels were randomized (1:1:1) to receive open-label remdesivir for 5 or 10 days or standard of care alone. The primary endpoint was the clinical status as assessed by a 7-point ordinal score at Day 11, ranging from hospital discharge to increasing levels of oxygen and ventilatory support to death. The secondary study objective was the rate of adverse events in each remdesivir treatment group compared with standard of care.

At Day 11, a higher proportion of patients in the 5-day treatment group achieved improvement in clinical status versus the standard of care group, achieving statistical significance for a ≥ 1-point improvement in ordinal scale (p=0.026). In addition, non-statistically significant increases in clinical worsening or death were observed in the standard of care only group compared with the remdesivir groups.