A trial looking at using antibiotics for chronic lymphocytic leukaemia (The CLEAR Trial)

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

Cancer type:

Blood cancers
Chronic leukaemia
Chronic lymphocytic leukaemia (CLL)




Phase 2

This trial is looking at using antibiotics Open a glossary item for early chronic lymphocytic leukaemia (CLL).

CLL can develop very slowly.  So if you have no symptoms your doctor may not give you any CLL treatment until you do.

Doctors are not sure what causes symptoms to develop.  But researchers think this may be linked to infections Open a glossary item.  The researchers in this trial want to give a short course of antibiotics to people with early CLL to find out if this might be true.

Who can enter

You may be able to enter this trial if you

  • Have chronic lymphocytic leukaemia (CLL) with less than 2 groups of enlarged lymph nodes Open a glossary item and a high white blood cell Open a glossary item count (stage A) and your doctor thinks your CLL can be well controlled (a good prognosis Open a glossary item) or less well controlled (a not so good prognosis) or have monoclonal B lymphocytosis (MBL) and no enlarged lymph nodes
  • Have CLL that has been stable for at least a month
  • Have satisfactory blood test results
  • Are well enough to be up and about for at least half the day (performance status 0, 1or 2)
  • Are willing to use reliable contraception while having treatment and for 4 weeks after if there is any chance you or your partner could become pregnant
  • Are at least 18 years old

You cannot enter this trial if you

  • Have an infection Open a glossary item
  • Are HIV positive
  • Are taking medications that could affect how the drugs in this trial work – your doctor can advise about this
  • Are pregnant or breastfeeding

Trial design

This is a phase 2 trial. It will recruit 180 people.

For 2 weeks, you take

  • The antibiotics metronidazole, clarithromycin and ciproflaxacin
  • Lansoprazole to protect your stomach
  • An anti fungal medicine called nystatin

Nystatin is a liquid and you take a teaspoon (5 ml) 3 times a day. The rest of the medications are tablets that you take twice a day. If you can, you should take all these medications on an empty stomach.

Antibiotics can sometimes make people feel sick.  If you feel sick at any time, you will also have an anti sickness tablet called domperidone that you can take up to 3 times a day.

You have a diary card to fill in to record when you take your tablets. If you agree to take part in this trial, the researchers will ask for extra blood samples and a sample of spit (saliva).  They will take another blood sample 6 months later.  They will use these samples to find out more about treatment for CLL.  You don’t have to agree to this if you don’t want to.  You can still take part in the main trial.

Hospital visits

You see the doctor twice for a physical examination and blood tests before starting treatment.

A week after starting treatment, the researchers will contact you by phone to see how you are.

After treatment you see the doctor at 6 weeks for a physical examination and blood test. You also hand in the completed diary card.

You then see the doctor at 6 months and 1 year for another examination and blood test.  You may have a bone marrow test if your doctor decides you need one.

Side effects

The most common side effects of the drugs used in this trial are

  • Loss of appetite
  • Feeling or being sick
  • Diarrhoea

You can’t drink any alcohol during treatment and for at least 48 hours after finishing, otherwise it could make you very sick.

We have more information about treatment for chronic lymphocytic leukaemia (CLL).

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

Dr Stephen Devereux

Supported by

Kings College Hospital NHS Foundation Trust
NIHR Clinical Research Network: Cancer

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 7443

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

Around 1 in 5 people take part in clinical trials

3 phases of trials

Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.

Last reviewed:

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