A Phase 1 interventional study of Valacyclovir in Neonatal Herpes Simplex Infection, sponsored by University of Alabama at Birmingham. Completed at 1 site in United States. Open to participants aged 2 Weeks to 12 Weeks. Per ClinicalTrials.gov, last updated 2025-06-24.
Sponsored by University of Alabama at Birmingham · Phase 1, Interventional, and Other
This is an open-label, single center, pharmacokinetic (PK) study to assess valacyclovir pharmacokinetics and pharmacodynamics in neonates and compare to the pharmacokinetics and pharmacodynamics of the standard of care treatment dose of intravenous acyclovir. 6 (up to 10 infants) with virologically confirmed neonatal herpes simplex virus (HSV) disease who meet all inclusion/exclusion criteria will be enrolled in the study. Study duration is 5 years. Primary objective is to define the pharmacokinetics of valacyclovir and assess its safety in neonates 2-12 weeks of age who are ≥ 34 weeks gestation.
This is an open-label, single center, PK study to assess valacyclovir pharmacokinetics and pharmacodynamics in neonates and compare to the pharmacokinetics and pharmacodynamics of the standard of care treatment dose of intravenous acyclovir. Only those babies with virologically confirmed neonatal HSV disease will be enrolled in the study. The decision to initiate valacyclovir for 2 (up to 7) days will be made by a physician based on inclusion/exclusion criteria, and those who meet entry criteria will be eligible for the study. Those enrolled in the study will have daily random parenteral acyclovir PK levels drawn during the first week of treatment (drawn only at times of other lab draws). These infants will also have a pharmacokinetic sampling profile obtained on or after dose 22 and before dose 42 of intravenous acyclovir. The PK samples for the sampling profile will be collected just prior to the next dose of intravenous acyclovir (within 30 minutes prior to the start of the infusion), within 15 minutes of completion of the infusion, and 3-4 hours after infusion. Upon completion of the recommended treatment course duration with intravenous acyclovir determined by disease classification (skin, eye, and mouth; central nervous system; or disseminated disease), the infant will be started on enteral valacyclovir 20 mg/kg every 8 hours.
On day 2 and no more than day 7 of valacyclovir 20 mg/kg every 8 hours, a pharmacokinetic sampling profile will be obtained. The PK samples will be collected just prior to the enteral dose of valacyclovir (hour 0; 8 hours after previous dose and immediately before next dose), 1-2 hours after dose, and 3-5 hours after dose. Primary objective is to define the pharmacokinetics of valacyclovir and assess its safety in neonates 2-12 weeks of age who are ≥ 34 weeks gestation. Secondary objectives are to: 1) assess the pharmacokinetics of high-dose parenteral acyclovir in neonates ≥ 34 weeks gestation with virologically confirmed neonatal HSV disease who are receiving acyclovir as standard of care, 2) compare the pharmacokinetics of high-dose parenteral acyclovir to the pharmacokinetics of the proposed study dose of valacyclovir (20 mg/kg every 8 hours).
University of Alabama at Birmingham is the lead sponsor of 1,396 studies on the registry; 284 are open to participants now.
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Exclusion Criteria:
All subjects enrolled in the study will receive 2 (up to 7) days of valacyclovir 20 mg/kg every 8 hours after completion of standard of care treatment course with acyclovir.
Drug: Valacyclovir
Upon completion of standard of care acyclovir for treatment of neonatal HSV disease, valacyclovir oral suspension (per ASHP recipe), 20 mg/kg every 8 hours, to be given for 2 (up to 7) days
Area Under the Curve Following Administration of Oral Valacyclovir Suspension 20 mg/kg Every 8 Hours
Blood will be collected to determine the drug concentration of acyclovir, the metabolite of valacyclovir and will include AUC.
Time frame: Between Day 2 and Day 7 of valacyclovir administration: 0, 1-2, 3-5 hours.
Creatinine Clearance Following Administration of Oral Valacyclovir Suspension 20 mg/kg Every 8 Hours
Blood will be collected to determine the drug concentration of acyclovir, the metabolite of valacyclovir and will include CL/F.
Time frame: Between Day 2 and Day 7 of valacyclovir administration: 0, 1-2, 3-5 hours.
Half-life Following Administration of Oral Valacyclovir Suspension 20 mg/kg Every 8 Hours
Blood will be collected to determine the drug concentration of acyclovir, the metabolite of valacyclovir and will include T1/2.
Time frame: Between Day 2 and Day 7 of valacyclovir administration: 0, 1-2, 3-5 hours.
Area Under the Curve Following Administration of Parenteral Acyclovir 20 mg/kg Every 8 Hours
This study will determine the blood concentrations of acyclovir flowing valacyclovir administration. The goal is to define the valacyclovir dose which will allow a switch from IV to PO medication. In so doing, the potential duration of hospitalization can be decreased. To achieve this end, blood is collected to determine AUC.
Time frame: One PK level drawn randomly on days 1-7; in addition, on one day between day 8 -14 of parenteral acyclovir, 3 PK levels to be drawn (drawn 30 minutes prior to infusion, 15 minutes after completion of infusion, and 3-4 hours after infusion)
Half-life Following Administration of Parenteral Acyclovir 20 mg/kg Every 8 Hours
This study will determine the blood concentrations of acyclovir flowing valacyclovir administration. The goal is to define the valacyclovir dose which will allow a switch from IV to PO medication. In so doing, the potential duration of hospitalization can be decreased. To achieve this end, blood is collected to determine T1/2 of drug.
Time frame: One PK level drawn randomly on days 1-7; in addition, on one day between day 8 -14 of parenteral acyclovir, 3 PK levels to be drawn (drawn 30 minutes prior to infusion, 15 minutes after completion of infusion, and 3-4 hours after infusion)
Creatinine Clearance Following Administration of Parenteral Acyclovir 20 mg/kg Every 8 Hours
This study will determine the blood concentrations of acyclovir flowing valacyclovir administration. The goal is to define the valacyclovir dose which will allow a switch from IV to PO medication. In so doing, the potential duration of hospitalization can be decreased. To achieve this end, blood is collected to determine creatinine clearance of drug.
Time frame: One PK level drawn randomly on days 1-7; in addition, on one day between day 8 -14 of parenteral acyclovir, 3 PK levels to be drawn (drawn 30 minutes prior to infusion, 15 minutes after completion of infusion, and 3-4 hours after infusion)
Comparison of the Area Under the Curve of 20 mg/kg IV Acyclovir to the Area Under the Curve of 20 mg/kg PO Valacyclovir
To determine if the concentration of the active metabolite acyclovir after administration of acyclovir and valacyclovir at specified time intervals produces the same area under the curve
Time frame: Random PK levels on days 1-7 of acyclovir administration, PK levels obtained on one day between day 8-14 at specified time intervals, and PK levels obtained one day while on valacyclovir (see outcome 1 and outcome 3 for time intervals)
| Milestone | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Started | 7 |
| Completed | 7 |
| Not completed | 0 |
Blood will be collected to determine the drug concentration of acyclovir, the metabolite of valacyclovir and will include AUC.
| mgxh/l | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Area Under the Curve Following Administration of Oral Valacyclovir Suspension 20 mg/kg Every 8 Hours | 28.8 ± 16.8 |
Blood will be collected to determine the drug concentration of acyclovir, the metabolite of valacyclovir and will include CL/F.
| L/h | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Creatinine Clearance Following Administration of Oral Valacyclovir Suspension 20 mg/kg Every 8 Hours | 3.1 ± 1.8 |
Blood will be collected to determine the drug concentration of acyclovir, the metabolite of valacyclovir and will include T1/2.
| hrs. | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Half-life Following Administration of Oral Valacyclovir Suspension 20 mg/kg Every 8 Hours | 2.7 ± 1.2 |
This study will determine the blood concentrations of acyclovir flowing valacyclovir administration. The goal is to define the valacyclovir dose which will allow a switch from IV to PO medication. In so doing, the potential duration of hospitalization can be decreased. To achieve this end, blood is collected to determine AUC.
| mgxh/L | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Area Under the Curve Following Administration of Parenteral Acyclovir 20 mg/kg Every 8 Hours | 70.1 ± 41 |
This study will determine the blood concentrations of acyclovir flowing valacyclovir administration. The goal is to define the valacyclovir dose which will allow a switch from IV to PO medication. In so doing, the potential duration of hospitalization can be decreased. To achieve this end, blood is collected to determine T1/2 of drug.
| hrs | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Half-life Following Administration of Parenteral Acyclovir 20 mg/kg Every 8 Hours | 2.5 ± 1.3 |
This study will determine the blood concentrations of acyclovir flowing valacyclovir administration. The goal is to define the valacyclovir dose which will allow a switch from IV to PO medication. In so doing, the potential duration of hospitalization can be decreased. To achieve this end, blood is collected to determine creatinine clearance of drug.
| L/h | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Creatinine Clearance Following Administration of Parenteral Acyclovir 20 mg/kg Every 8 Hours | 1.1 ± 0.4 |
To determine if the concentration of the active metabolite acyclovir after administration of acyclovir and valacyclovir at specified time intervals produces the same area under the curve
| AUC- mgxh/l | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| PO valacyclovir AUC | 28.8 ± 16.8 |
| IV acyclovir AUC (linear adjustment) | 74 ± 41.0 |
Collected over 1 year. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Neonatal HSV Disease Requiring Suppressive Therapy | 0/7 (0%) | 0/7 (0%) | 0/7 (0%) |
| Age, Customized(Participants) | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| 0-20 days | 4 |
| 21-42 days | 3 |
| Sex: Female, Male(Participants) | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Female | 2 |
| Male | 5 |
| Race (NIH/OMB)(Participants) | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 1 |
| White | 6 |
| More than one race | 0 |
| Unknown or Not Reported | 0 |
| Age at time of parental acyclovir profile (days)(days) | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Median | 30 (13 to 39) |
| Age at time of valacyclovir profile (days)(days) | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Median | 35 (19 to 48) |
| Interval between parental acyclovir and valacyclovir profile (days)(days) | Neonatal HSV Disease Requiring Suppressive Therapy |
|---|---|
| Mean | 6 (3 to 14) |
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University of Alabama at Birmingham