Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Contact information



Primary contact

Mr Stephen Baker


Contact details

Cancer Research UK Clinical Trials Unit
Institute for Cancer Studies
B15 2TT
United Kingdom

Additional identifiers

EudraCT number

2013-001332-22 number

Protocol/serial number


Study information

Scientific title

PEPtalk 2: Pilot of a randomised controlled trial to compare VZIG and aciclovir as post-exposure prophylaxis against chickenpox in children with cancer


PEPtalk 2

Study hypothesis

Treatment for cancer in children often includes the use of anti-cancer drugs called chemotherapy. Some chemotherapy drugs can reduce the production of white blood cells, which lowers a child's immunity. This means that some infections that are usually mild in healthy children can be more difficult for a child with cancer to cope with. Chickenpox is one of these infections and it can be life-threatening for a child with cancer.

It is therefore important to try to prevent children with cancer from developing chickenpox. If a child with cancer has close contact with someone who is infectious for chickenpox, they are usually offered preventative medicine. This is called post-exposure prophylaxis (PEP). There are two different types of PEP used in the UK and medical opinion is divided over which is better. So about half of children receive VZIG, an injection of chickenpox antibodies into the muscle, while the other half of children receive aciclovir, an orally administered course of antiviral medicine.

This pilot trial aims to prepare for a main Phase III trial, the aim of which will be to find out whether aciclovir is at least as good as VZIG in protecting against chickenpox in children with cancer. This pilot study will help to inform a sample size calculation; it will test the components of the larger study; and it will test how acceptable the trial procedures are to parents, patients and clinicians. A secondary aim is to establish whether these two treatments have different costs to the health service and the effects on patients’ quality of life. A health economic analysis will be performed accordingly.

Ethics approval

13/LO/0551; First MREC approval date 14/05/2013

Study design

Randomised; Interventional; Design type: Treatment

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet


Topic: National Cancer Research Network, Medicines for Children Research Network; Subtopic: All Cancers/Misc Sites, All Diagnoses; Disease: All, All Diseases


Trial Treatment, Both trial arms are 'standard' treatments although which is the standard varies from one centre to another. Some patients may therefore receive an intramuscular injection, by way of the trial treatment, in circumstances where they would more commonly receive oral therapy, and vice versa. The potential risks and discomfort associated with both therapies are explained in the Parent/Patient Information Sheets and clinicians will also explain these to parents and (where possible) patients when takin

Intervention type



Phase II/III

Drug names

Primary outcome measure

The number of patients randomised within 12 months of the trial

Secondary outcome measures

Not provided at time of registration

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

For registration:
1. Under 16 years of age
2. EITHER diagnosed with cancer such that there is a standard expectation of immunocompromising therapy OR currently receiving immunocompromising treatment for cancer OR within 3 months of having received immunocompromising treatment for cancer
3. No current or previous allogeneic or autologous haemopoietic stem cell transplantation / rescue
4. Negative VZV serostatus result at cancer diagnosis or negative VZV serostatus result within the last 3 months as assessed locally
5. Written informed consent to registration received from parent/legal representative and, where appropriate, written patient assent

For randomisation:
1. Patient has previously been registered in the PEPtalk2 trial, having satisfied all registration requirements
2. Registration criterion (c) continues to apply
3. Immunocompromising treatment for cancer must have been initiated prior to VZV exposure
4. Patient is able to commence either VZIG no more than 10 days after experiencing VZV exposure, or aciclovir at 7 days after experiencing VZV exposure (see sections 5.1.2 and 5.1.3)
5. No renal impairment. Renal impairment is expressed in terms of glomerular filtration rate (ml/min/1.73m2). Child over 1 year: Estimated glomerular filtration rate (ml/min/1.73m2) =
40 x height (cm) x serum creatinine (micromol/litre). Normal renal function: > or equal to 90ml/min/1.73m2
6. Written informed consent to randomisation received from parent/legal representative and, where appropriate, written patient assent

Important note regarding thrombocytopenia: platelets must be > 50 x 109/L to receive an intramuscular injection of VZIG. Therefore, if a child is randomised to receive VZIG and platelets are found to be < 50 x 109/L no more than 48 hours prior to VZIG administration, arrangements must be made by local staff to administer a platelet transfusion prior to VZIG injection. There are no criteria for platelet count if randomised to acyclovir.

Participant type


Age group




Target number of participants

Planned Sample Size: 50; UK Sample Size: 50

Participant exclusion criteria

Exclusion from Registration:
1. 16 years of age or over
2. Current or previous allogeneic or autologous haemopoietic stem cell transplant/rescue
3. Positive VZV serostatus result as assessed locally within the last 3 months
Note: renal impairment and thrombocytopenia are not absolute contraindications for registration as they might resolve by the time a chickenpox exposure and screening for randomisation occur

Exclusion from randomisation:
1. Positive VZV serostatus result at time of screening
2. Contraindication to either aciclovir or VZIG, including:
2.1. thrombocytopenia (platelets < 50 x 109/L) that has not been corrected by platelet transfusion
2.2. renal impairment (exclude any child with GFR below 90ml/min/1.73m2)
2.3. any other contraindications deemed to be relevant by the local Investigator or the Sponsor’s Clinical Coordinator(s)
3. Inability to start either VZIG within 10 days of VZV exposure, or acyclovir at 7 days after VZV exposure
4. More than one VZV exposure within the past 12 weeks
5. Inability to tolerate medications via oral or enteral route
6. Pregnancy or lactation

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Cancer Research UK Clinical Trials Unit
B15 2TT
United Kingdom

Sponsor information


University of Birmingham (UK)

Sponsor details

Birmingham Clinical Trials Unit
Division of Cancer Studies
Robert Aitken Institute

B15 2TT
United Kingdom

Sponsor type




Funder type


Funder name

Research for Patient Benefit Programme

Alternative name(s)

NIHR Research for Patient Benefit Programme, RfPB

Funding Body Type

government organisation

Funding Body Subtype

National government


United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1. 2018 results in (added 22/01/2019)

Publication citations

Additional files

Editorial Notes

22/01/2019: Publication reference added 12/01/2018: No publications found, verifying study status with principal investigator.