This study evaluated the efficacy and safety of remdesivir, an RNA polymerase inhibitor, in treating severe Covid-19 patients. A randomized, open-label, phase 3 trial was conducted involving 397 hospitalized patients with confirmed SARS-CoV-2 infection and radiologic evidence of pneumonia. Patients were randomly assigned to receive intravenous remdesivir for either 5 or 10 days. The primary endpoint was clinical status on day 14, assessed on a 7-point ordinal scale. The median duration of treatment was 5 days for the 5-day group and 9 days for the 10-day group. Patients in the 10-day group had significantly worse clinical status at baseline compared to the 5-day group. By day 14, 64% of patients in the 5-day group and 54% in the 10-day group showed a clinical improvement of at least 2 points. After adjusting for baseline clinical status, the distribution of clinical status at day 14 was similar between the two groups. The most common adverse events were nausea, worsening respiratory failure, elevated liver enzymes, and constipation. The study concluded that there was no significant difference in efficacy between a 5-day and a 10-day course of remdesivir in patients with severe Covid-19 not requiring mechanical ventilation. However, the lack of a placebo control limits the interpretation of these results.This study evaluated the efficacy and safety of remdesivir, an RNA polymerase inhibitor, in treating severe Covid-19 patients. A randomized, open-label, phase 3 trial was conducted involving 397 hospitalized patients with confirmed SARS-CoV-2 infection and radiologic evidence of pneumonia. Patients were randomly assigned to receive intravenous remdesivir for either 5 or 10 days. The primary endpoint was clinical status on day 14, assessed on a 7-point ordinal scale. The median duration of treatment was 5 days for the 5-day group and 9 days for the 10-day group. Patients in the 10-day group had significantly worse clinical status at baseline compared to the 5-day group. By day 14, 64% of patients in the 5-day group and 54% in the 10-day group showed a clinical improvement of at least 2 points. After adjusting for baseline clinical status, the distribution of clinical status at day 14 was similar between the two groups. The most common adverse events were nausea, worsening respiratory failure, elevated liver enzymes, and constipation. The study concluded that there was no significant difference in efficacy between a 5-day and a 10-day course of remdesivir in patients with severe Covid-19 not requiring mechanical ventilation. However, the lack of a placebo control limits the interpretation of these results.