This study evaluates the efficacy and safety of REGN-COV2, a cocktail of two neutralizing monoclonal antibodies against SARS-CoV-2, in reducing viral load and preventing medically attended visits in nonhospitalized outpatients with Covid-19. The trial is ongoing, double-blind, and phase 1–3, involving 275 patients randomly assigned to receive placebo, 2.4 g, or 8.0 g of REGN-COV2. Key endpoints include the time-weighted average change in viral load from baseline through day 7 and the percentage of patients with at least one medically attended visit through day 29. Safety was assessed in all patients. The results show that REGN-COV2 reduced viral load, with a greater effect in patients who were serum antibody-negative at baseline or had high viral loads. The percentage of patients with medically attended visits was significantly lower in the REGN-COV2 groups compared to the placebo group, particularly in serum antibody-negative patients. Safety outcomes were similar across the REGN-COV2 dose groups and the placebo group. The study suggests that REGN-COV2 can enhance viral clearance and improve clinical outcomes, especially in patients with a slow immune response.This study evaluates the efficacy and safety of REGN-COV2, a cocktail of two neutralizing monoclonal antibodies against SARS-CoV-2, in reducing viral load and preventing medically attended visits in nonhospitalized outpatients with Covid-19. The trial is ongoing, double-blind, and phase 1–3, involving 275 patients randomly assigned to receive placebo, 2.4 g, or 8.0 g of REGN-COV2. Key endpoints include the time-weighted average change in viral load from baseline through day 7 and the percentage of patients with at least one medically attended visit through day 29. Safety was assessed in all patients. The results show that REGN-COV2 reduced viral load, with a greater effect in patients who were serum antibody-negative at baseline or had high viral loads. The percentage of patients with medically attended visits was significantly lower in the REGN-COV2 groups compared to the placebo group, particularly in serum antibody-negative patients. Safety outcomes were similar across the REGN-COV2 dose groups and the placebo group. The study suggests that REGN-COV2 can enhance viral clearance and improve clinical outcomes, especially in patients with a slow immune response.