A study looking at VZIG or aciclovir for children who have been exposed to chicken pox during cancer treatment (PEPtalk2)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Children's cancers





This study is comparing the drugs VZIG and aciclovir for children who are having cancer treatment and have been in contact with someone who has chicken pox.

This study is for children up to the age of 16. We use the term ‘you’ in the summary, but of course if you are a parent, we are referring to your child.

Cancer treatment for children often includes chemotherapy. Having chemotherapy can increase your risk of getting infections because it damps down your immune system. It may be more difficult for a child with cancer to cope with an infection that would usually be mild in healthy children. Chickenpox is one of these infections.

If a child with cancer has close contact with someone with chickenpox, they are usually offered medicine to try to stop them getting chickenpox. There are 2 different types of medicine used in the UK

  • An injection called VZIG
  • Aciclovir tablets that you take for 2 weeks

But doctors aren't sure which treatment is better. The aim of this pilot study is to see if it would be possible to run a large trial to answer this question.

Who can enter

You may be able to join this study if all of the following apply. You

  • Are under 16
  • Have been diagnosed with cancer
  • Are having (or are going to have) treatment such as chemotherapy that damps down your immune system, or you have had this type of treatment in the last 6 months

You cannot join this study if any of these apply. You

  • Are having (or have had) a stem cell transplant
  • Have been exposed to chickenpox more than once in the last 3 months
  • Can't swallow tablets (or have them via a feeding tube if you have one in place)
  • Are pregnant or breastfeeding

Trial design

This is a pilot study. The researchers need about 50 children to take part. If you agree to join the study, you have a blood test to see if you have already been exposed to chickenpox. If the test shows that you have, you won't have any further tests or treatment in this study.

But if the test is negative and you then come into contact with somebody who has chickenpox after you've started your cancer treatment, you will have another blood test at this time. The study team will then offer you treatment to try to stop you getting chickenpox.

This part of the study is randomised. Unless there is a specific reason why you can't have either of the drugs in this study, the treatment you have is decided by computer. Neither you nor your doctor can choose which treatment you have.

Half the children have a VZIG injection into a muscle. The other half take aciclovir tablets for 2 weeks. The study team will give you (or your parents) a diary to fill in at home. In this, you write down how you are and any symptoms you have.

They will also ask you to fill out a questionnaire on 3 occasions. This will ask about side effects. It is called a quality of life study.

You see the study team again about 3 months later and have one more blood test.

If you do develop chicken pox, you will have the same treatment as you would have if you weren't taking part in the study.

Hospital visits

You may have up to 3 extra blood tests if you join this study.

Side effects

The side effects of VZIG include

  • Swelling, pain, rash or itching where you have the injection
  • Feeling or being sick
  • Headaches
  • A fast heartbeat
  • Low blood pressure
  • Aching joints and limbs
  • Feeling generally unwell

The side effects of aciclovir include

  • Feeling and being sick
  • Diarrhoea
  • Tummy (abdominal) pain
  • Rash
  • Tiredness (fatigue)

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Paul Heath

Supported by

Cancer Research UK Clinical Trials Unit University of Birmingham
NIHR Clinical Research Network: Cancer
NIHR Research for Patient Benefit (RfPB) Programme
St George's Healthcare NHS Trust
University of Birmingham

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 11340

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Katie took part in a new clinical trial

A picture of Katie cycling

"We believed that with the clinical trial, Katie had the best chance of recovery. Without these trials, amazing new treatments may never be found."

Last reviewed:

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