A Study to Evaluate the Single Dose Safety, Tolerability and Pharmacokinetics of IV BCX4430

Key Inclusion Criteria: * written informed consent * males and non-pregnant, non-lactating females * BMI 19.0-32.0 * willing to abide by contraceptive requirements * normal vitals * willing to abide by study procedures and restrictions Exclusion Criteria: * clinically significant medical condition or medical history or psychiatric condition or history of psychiatric condition * abnormal cardiac finding, or laboratory/urinalysis abnormality at screening * known family history of sudden death or long QT syndrome, family or personal history of QT prolongation, or arrhythmia that required medical intervention * current participation in any other investigational drug study or participation in an investigational drug study within 3 months of screening visit * use of prescription, OTC, or herbal medications during study or use of any specified medications within 30 days prior to study * Recent or current history of alcohol or drug abuse * Regular use of tobacco or nicotine products * Positive serology for HBV, HCV, or HIV * history of severe adverse reaction to or known sensitivity to any drug * pregnant, lactating, or planning to become pregnant within 30 days of the study. Male subjects with pregnant female partners are excluded