2 June 2020 - - US-based biopharmaceutical company Gilead Sciences, Inc. (NASDAQ: GILD) has released 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% more likely to have clinical improvement at Day 11 compared with those in the standard of care group (OR 1.65 [95% CI 1.09-2.48]; p=0.017).

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 (OR 1.31 [95% CI 0.88-1.95]; p=0.18).

No new safety signals were identified with remdesivir across either treatment group. Gilead plans to submit the full data for publication in a peer-reviewed journal in the coming weeks.

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 US Food and Drug Administration 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.

Remdesivir was generally well-tolerated in both the 5-day and 10-day treatment groups. The most common adverse events occurring in more than 5 % of patients in both treatment groups were nausea (5-day: 10% / 10-day: 9% / SOC:3%), diarrhea (5-day: 5% / 10-day: 5% / SOC: 7%) and headache (5-day: 5% / 10-day: 5% / SOC:3%).

Gilead initiated two randomised, open-label, multi-center Phase 3 clinical trials for remdesivir, the SIMPLE studies, in countries with a high prevalence of COVID-19 infections.

The studies were conducted at more than 180 trial sites around the world, including sites in the United States, China, France, Germany, Hong Kong, Italy, Japan, Korea, the Netherlands, Singapore, Spain, Sweden, Switzerland, Taiwan and the United Kingdom.

The first SIMPLE trial is evaluating the safety and efficacy of 5-day and 10-day dosing durations of remdesivir administered intravenously in hospitalized patients with severe manifestations of COVID-19. The initial phase of the study randomised 397 patients in a 1: 1 ratio to receive either a 5-day or a 10-day treatment course of remdesivir in addition to standard of care.

Topline results were announced on April 29 and the full data were published in The New England Journal of Medicine on May 27. An expansion phase of the study was added to enroll up to 5,600 additional patients, including those on mechanical ventilation.

The second SIMPLE trial is evaluating the safety and efficacy of 5-day and 10-day dosing durations of remdesivir administered intravenously in hospitalized patients with moderate manifestations of COVID-19, compared with standard of care.

The initial phase of the study randomized 600 patients in a 1: 1: 1 ratio to receive either a 5-day or a 10-day treatment course of remdesivir in addition to standard of care, compared with standard of care alone. An expansion phase of the study was added to enroll up to 1,000 additional patients with moderate disease.

The initial study results are announced in this press release, and results from the expansion phase are expected in the coming months.

Remdesivir (GS-5734) is authorized for use under an Emergency Use Authorization only for the treatment of patients with suspected or laboratory-confirmed SARS-CoV-2 infection and severe COVID-19. SARS-CoV-2 is the coronavirus that causes COVID-19 disease.

Severe disease is defined as patients with an oxygen saturation ≤ 94% on room air or requiring supplemental oxygen or requiring mechanical ventilation or requiring extracorporeal membrane oxygenation.

Remdesivir is authorised for adult or pediatric patients who are admitted to a hospital and for whom use of an IV agent is clinically appropriate, as remdesivir must be administered intravenously.

Remdesivir is an investigational drug that has not been approved by the FDA for any use. It is not yet known if remdesivir is safe and effective for the treatment of COVID-19.

This use of remdesivir is authorised only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use, unless the authorization is terminated or revoked sooner.