Pharmacokinetics of Valacyclovir Oral Solution in Children

Study Overview
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Brief Summary
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Valacyclovir has replaced acyclovir in many clinical scenarios. Pharmacokinetic data support the use of oral valacyclovir in children, but practical problems exist in children having to take adult-dose tablets. A formulation with acceptable palatability, good pharmaceutical quality and possibility of flexible dosing is developed. Pharmacokinetic data of this formulation is missing. The present study investigates the pharmacokinetics of valacyclovir oral solution in children by determine the area under the curve (AUC0-12), time above critical concentration (Ccrit), Cmax and Tmax of acyclovir. Secondary, the safety profile of a single dose of valacyclovir oral solution will be determined.

Official Title
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Pharmacokinetics of a New Paediatric Formulation of Valacyclovir Used for Prophylaxis and Treatment of Varicella Zoster Virus (VZV) and Herpes Simplex Virus (HSV) Infections in Children, Phase II (VALID II)

Conditions
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Herpes Simplex Virus Infection, Varicella Zoster Virus Infection

Intervention / Treatment
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* Drug: Valacyclovir


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject is in the age of 2-12 years. Subject has an indication for (val)acyclovir prophylaxis and are planned to receive valacyclovir oral solution. Subject is managed with a central venous catheter (CVC/Port-a-Cath). Subject's parents have signed the Informed Consent Form prior to screening evaluations. Subject is willing to participate after study procedures are explained in comprehensible language for the child. Exclusion Criteria: Severe anemia (<6.0 mmol/L). Full dose has not been taken.

Ages Eligible for Study
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Minimum Age: 2 Years
Maximum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Interventional Model Description: Intervention is pharmacokinetic (PK) curve collection in children, two age groups
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Valacyclovir oral solution<br>Valacyclovir oral solution as administered in standard of care. Dosage: 10 mg/kg BID for children weighing less than 40 kg and 500 mg BID for children weighing 40 kg or more. | Drug: Valacyclovir<br>* PK curve collection to determine acyclovir exposure after administration of valacyclovir oral solution<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area under the curve | Acyclovir area under the curve (12h) | 12 hours | 
| Cmax | Maximum concentration of aciclovir | 12 hours | 
| Tmax | Time to reach maximum concentration of aciclovir | 12 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of adverse events | Number of adverse events | 1 day |