A quantitative systems pharmacology (QSP) model of the pathogenesis and treatment of SARS-CoV-2 infection can streamline and accelerate the development of novel medicines to treat COVID-19. Simulation of clinical trials allows in silico exploration of the uncertainties of clinical trial design and can rapidly inform their protocols. The development of a QSP model to support novel COVID-19 therapies will be discussed. The model accounts for the interactions between viral dynamics, the major host immune response mediators and tissue damage. The model recapitulates the evolution of viral and immune dynamics in subjects with COVID-19 in outpatient and hospitalized settings. An initial validation of the model response is performed against publicly available data on SARS-CoV-2 neutralizing antibody treatments.