Remdesivir plus dexamethasone versus dexamethasone alone for the treatment of COVID-19 patients requiring supplemental O2 therapy: a prospective controlled non-randomized study

Background: Remdesivir is an antiviral used to treat COVID-19 which improves some clinical outcomes. Dexamethasone has been shown to be effective in reducing mortality. It has been hypothesized that combination of these two drugs can improve mortality. We evaluated the effect of combination on mortality of COVID-19 patients requiring O2 therapy. Methods: A prospective quasi-experimental study, including two independent, sequential controlled cohorts, one received remdesivir-dexamethasone and the other dexamethasone alone, was designed. All COVID-19 patients requiring supplemental O2 therapy were enrolled consecutively. The sample size to power mortality was a priori calculated. The primary endpoints were 30-day mortality and viral clearance differences. Secondary endpoints were differences in hospitalization times, improvement in respiratory failure (PO2/FiO2) and inflammatory indices (fibrinogen, CRP, neutrophil/lymphocyte ratio, D-Dimer). Kaplan-Meier curves and the log-rank test were used to evaluate significant differences in mortality between groups. Results: 151 COVID-19 patients were enrolled (remdesivir/dexamethasone group, 76 and dexamethasone alone,75). No differences in demographic, clinical and laboratory characteristics were observed between the two groups at baseline. Faster viral clearance occurred in the remdesivir/dexamethasone group compared to dexamethasone alone (median 6 vs 16 days; p<0.001). 30-days mortality in the remdesivir/dexamethasone group was 1.3%, while in dexamethasone alone was 16% (p<0.005). In the remdesivir/dexamethasone group compared to dexamethasone alone there was a reduction in hospitalization days (p<0.0001) and a faster improvement in both respiratory function and inflammatory markers. Conclusions: Remdesivir/dexamethasone treatment is associated with significant reduction in mortality, length of hospitalization, and faster SARS-CoV-2 clearance, compared to dexamethasone alone