Summary Arenaviruses comprise a diverse family. Several species are associated with severe arenaviral hemorrhagic fever (AVHF) in humans. Human infection with arenaviruses typically occurs through contact with materials contaminated with the excretions of an infected rodent although direct human- to-human transmission may occur in clinical settings. AVHF resulting from infection with the Old World arenavirus Lassa is estimated to cause over 300,000 annual infections in Western Africa, of which 15-20% of hospitalized patients die while survivors often suffer permanent sequelae. Given the limited treatment and prophylactic options, the mortality/morbidity rate, the potential for both zoonotic and human-to-human transmission, geographical transplantation and bio-weaponization six arenaviruses have been recognized as Category A pathogens. Currently, we have a clinical highly potent arenavirus entry inhibitor in Phase 1 clinical trial with comparable activity for all six Category A arenaviruses. The manufacturing of the compound requires 3 step synthesis with yields of 60-80% and purity >99.5%. In addition, the compound is amenable to simple formulation for both tablets and capsules with suitable oral bioavailability and half-life to support once or twice-a-day dosing. Here we propose initiating steps toward registration of both drug substance and product by evaluating, validating and locking down manufacturing processes and in parallel manufacture the first of 3 registration drug product batches to be used for Phase 3 clinical trial.