Phase 1 Study Evaluating Safety, Tolerability, Pharmacokinetics and Immunogenicity of REGN2222 in Healthy Adults: A New Human Monoclonal RSV-F Antibody for RSV Prevention

Abstract

Background. RSV infection is a major cause of acute respiratory infections in infants. REGN2222 is a human monoclonal IgG1 antibody against RSV-F that is effective in reducing RSV viral load in cotton rat lungs. We conducted a randomized double blinded, placebo controlled Phase 1 study in healthy adults to assess safety, tolerability, pharmacokinetics and immunogenicity of REGN2222.Methods. 132 healthy adults, age 18-60 years, were randomized into one of 5 cohorts: 3 ascending IV dose cohorts at 3 mg/kg, 10 mg/kg or 30 mg/kg, or placebo and 2 ascending IM dose cohorts at 3 mg/kg or 10 mg/kg, or placebo. Eight subjects (REGN2222/placebo; 6:2) were randomized to 3 mg/kg IV × 1 dose; 15 subjects (12:3) to cohort 10 mg/kg IV × 1 dose; 15 subjects (12:3) to 30 mg/kg IV × 2 doses (4 weeks apart); 47 subjects (40:7) to 3 mg/kg IM × 2 doses (4 weeks apart); and 47 subjects (40:7) to 10 mg/kg IM × 2 doses (4 weeks apart).