Phase 1 study of safety, pharmacokinetics, and antiviral activity of SARS-CoV-2 neutralizing monoclonal antibody ABBV-47D11 in patients with COVID-19

ABBV-47D11 is a neutralizing monoclonal antibody that targets a mutationally conserved hydrophobic pocket distal to the ACE2 binding site of SARS-CoV-2. This first-in-human safety, pharmacokinetics, and antiviral pharmacodynamic assessment in patients with COVID-19 provide an initial evaluation of this antibody that may allow further development. This multicenter, randomized, double-blind, and placebo-controlled single ascending dose study of ABBV-47D11 (180, 600, or 2400 mg) as an intravenous infusion, was in hospitalized and non-hospitalized (confined) adults with mild to moderate COVID-19. Primary outcomes were grade 3 or higher study drug-related adverse events and infusion-related reactions. Secondary outcomes were pharmacokinetic parameters and concentration-time profiles to Day 29, immunogenicity (anti-drug antibodies), and antiviral activity (change in RT-PCR viral load) from baseline to Days 15 and 29. ABBV-47D11 single doses up to 2400 mg were safe and tolerated and no safety signals were identified. The pharmacokinetics of ABBV-47D11 were linear and showed dose-proportional increases in serum concentrations with ascending doses. The exploratory anti-SARS-CoV-2 activity revealed a reduction of viral load at and above the 600 mg dose of ABBV-47D11 regardless of patient demographics and baseline characteristics, however; because of the high inter-individual variability and small sample size a statistical significance was not reached. There is potential for anti-SARS-CoV-2 activity with ABBV-47D11 doses of 600 mg or higher, which could be evaluated in future clinical trials designed and powered to assess viral load reductions and clinical benefit.