Pharmacokinetic profiles of a SARS‐COV‐2 neutralizing antibody BD‐604 in cynomolgus monkeys

Gao, Feng; Zhang, Xu

BACKGROUND: Currently, severe acute respiratory syndrome coronavirus 2 (SARS‐COV‐2) has spread worldwide as a severe pandemic and effective therapeutic medications are urgently needed. As reported previously, BD‐604 is a fully human monoclonal antibody with strong in vitro and in vivo neutralizing activity to SARS‐COV‐2. OBJECTIVE: The purpose of this study was to characterize the pharmacokinetic propertie of BD‐604 in cynomolgus monkeys. METHODS: To analyze the concentration of BD‐604 in cynomolgus monkey serum, an ELISA assay was established, and a systemic validation was performed including accuracy and precision, dilution linearity and hook effect, selectivity, specificity, stability, and parallelism tests. Then, six naïve cynomolgus monkeys (3/sex) were administered BD‐604 at a single dose of 10 mg/kg via intravenous infusion (60 min). Blood samples were collected at various time points (0–672 h) and analyzed for serum concentrations of BD‐604. RESULTS: The data from validation experiments assure the reproducibility and reliability of the established ELISA assay. Then, the validated method was used to measure BD‐604 concentration in cynomolgus monkey serum. The pharmacokinetics parameters including terminal half‐life (t(1/2)), peak serum concentration (C(max)), area under curve from time zero to last timepoint or infinity (AUC(last)/AUC(inf)), apparent volume of distribution (V(z)), clearance rate (CL), and mean residence time (MRT) were calculated and reported. BD‐604 showed no marked sex differences at the dose of 10 mg/kg when comparing the AUC(0‐last) and C(max) between female and male cynomolgus monkeys. CONCLUSION: In cynomolgus monkeys, BD‐604 possesses pharmacokinetic properties similar to natural IgGs.