Summary – Core C Core C will provide AC/DC Cores and Projects with the drug metabolism, pharmacokinetic and toxicology (DMPK/Tox) data that is required to guide lead optimization, tolerability, and pharmacodynamic profiling. Core C brings industry seasoned expertise and a successful track record of drug development as exemplified by the preclinical characterization of molnupiravir (under consideration for Emergency Use Authorization as a treatment for SARS-CoV-2 infections), and EIDD-2173 (currently in Phase 2 clinical trials for hepatitis B virus infections). All AC/DC DMPK/Tox operations have accordingly been centralized into Core C to provide the synergies realized by generating data that is crucial and applicable to multiple projects, and to avoid redundant studies. The solubility, stability cellular uptake and cellular metabolic profiles of validated hits and early leads will be determined to filter those with a low probability of success and to inform iterative discovery and optimization. Drug metabolism, pharmacokinetic and tissue distribution data will be provided to inform animal efficacy studies and lead optimization. Finally, the tolerability of late leads will be assessed with both in vitro assays and non- GLP dose range finding toxicokinetic studies.