Regdanvimab for patients with mild-to-moderate COVID-19: a retrospective cohort study and subgroup analysis of patients with the Delta variant

OBJECTIVES: To evaluate the efficacy and safety of regdanvimab, a neutralizing antibody, in patients with mild-to-moderate SARS-CoV-2 including against the Delta variant. METHODS: A single-center, retrospective, observational cohort study in adults with confirmed COVID-19. The primary end point was the proportion of patients deteriorating with peripheral oxygen saturation <90% in room air, requiring supplemental oxygen therapy above high flow, or experiencing mortality due to COVID-19 up to day 28. RESULTS: A total of 722 patients were eligible; 418 received regdanvimab and 304 received standard of care (SoC), of whom 71.1% (297/418, regdanvimab) and 37.8% (115/304, SoC) were infected with the Delta variant. The proportion of patients with a primary end point event was significantly lower with regdanvimab than SoC (3.1% vs 9.9%; difference: -6.8 [95% confidence interval: -10.9, -2.8]; P = 0.0002). A similar trend was observed in the Delta variant subgroup (regdanvimab, 2.7% vs SoC, 7.0%; difference -4.3 [95% confidence interval: -10.8, 0.2]; P = 0.0827). The secondary efficacy end points supported the primary analysis findings in the overall cohort and Delta variant subgroup. No new safety signals were identified. CONCLUSION: Regdanvimab demonstrated clinical efficacy in the overall cohort and may provide a clinical benefit for patients with mild-to-moderate COVID-19 infected with the Delta variant.