Pediatric Trials Network studies lead to FDA approval of acyclovir labeling supplement

February 14, 2019 – The antiviral drug’s label will now include dosing information for infants, drawing on results from two pediatric studies led by DCRI investigators.

Research conducted by the Pediatric Trials Network (PTN) has led the U.S. Food and Drug Administration (FDA) to update the prescribing information, or drug label, of acyclovir to include dosing for infants with Neonatal Herpes Simplex Virus (HSV).

Infant yawning

The DCRI has acted as the coordinating center for the PTN since 2010 when it received its original funding from the National Institutes of Health (NIH). The findings that led to the acyclovir labeling supplement were from two studies led by DCRI primary investigators: An Open-Label Study to Describe the Pharmacokinetics of Acyclovir in Premature Infants and Efficacy of Antiviral Suppression Therapy After Neonatal HSV Infection of the Central Nervous System.

Acyclovir (brand name Zovirax) is an antiviral drug used in the pediatric population to treat HSV, a highly contagious virus that can be very serious for babies. Because an infant’s immune system is not fully developed to fight off the virus, the disease can result in death or mental disabilities. While appropriate dosing of acyclovir was known for adults and children, acyclovir had not been adequately studied in full-term or preterm infants.

In the two associated PTN studies, 32 infants were enrolled. The first study, which determined the appropriate dosage of acyclovir for infants, was conducted at a single medical center in preterm and term infants with suspected HSV infection. The second study, which validated the safety and efficacy of the dosage, involved multiple medical centers and enrolled only preterm infants with suspected HSV infection. The DCRI’s Daniel K. Benjamin, MD, PhD, MPH, served as a principal investigator for the first study, and the DCRI’s P. Brian Smith, MD, MPH, MHS, served as a principal investigator for both studies.

Based upon the pharmacokinetic (how a drug travels through the body) results, the FDA updated the label to include dosing in infants based on their post-menstrual age (PMA), or the time that had elapsed since the mother’s last menstrual cycle. PMA is especially useful in preterm infants because it characterizes the baby’s expected developmental age.

Last year, the PTN contract was renewed by the National Institute of Child Health and Human Development (NICHD) for another eight years of pediatric research.