Neonatal Phase 1 Valacyclovir Study

A Phase 1 study that will determine the valacyclovir dose that results in a systemic acyclovir exposure comparable to 10 mg/kg of parenterally administered acyclovir, which is an AUC0-12 of 24,000 ngxhr/mL to 48,000 ngxhr/mL. Neonates at risk of acquiring neonatal HSV will be enrolled in one of 2 cohorts. Cohort 1 will be comprised of eight subjects who will receive an initial dose of 10ml/kg of oral valacyclovir. Samples for PK assessments will be obtained to assess the exposure concentration. If the safety profile and the drug exposure concentrations in Cohort 1 are acceptable, eight new subjects will be enrolled in Cohort 2. The dose that these subjects will receive will be predicated upon the pharmacokinetic data from Cohort 1.