A trial to see if atovaquone can increase the level of oxygen in non small cell lung cancer (ATOM)

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

Cancer type:

Lung cancer
Non small cell lung cancer




Phase 0

This trial is for people with non small cell lung cancer (NSCLC) who are going to have surgery. It is for people going to Churchill Hospital in Oxford.

More about this trial

Non small cell lung cancer (NSCLC) is the most common type of lung cancer. It is often treated with surgery.  

Most cancers, including NSCLC, have cells with a low level of oxygen Open a glossary item. The medical term for this is hypoxia. We know from previous research that cancers with a low level of oxygen don’t respond as well to treatments, such as radiotherapy, as cancer cells with a normal oxygen level. 

Atovaquone is a drug used to treat certain infections such as malaria. Doctors think it can also increase the level of oxygen in cancer cells. If cancer cells have more oxygen, treatments may work better. 

This trial is in 2 parts (cohorts). In the 1st cohort everyone had atovaquone before surgery to remove NSCLC. Cohort 1 is now closed and doctors are looking for people to join cohort 2. In the 2nd cohort, people only have surgery. 

The main aim of this trial is to find out if atovaquone can reduce the level of hypoxia in NSCLC.

Who can enter

The following bullet points list the entry conditions for this trial. Talk to your doctor or the trial team if you are unsure about any of these. They will be able to advise you. 

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

  • have, or your doctor thinks you have, NSCLC and you are going to have surgery 
  • have at least 1 area of cancer that measures more than 2 cm and that your doctor thinks has a low level of oxygen  
  • have satisfactory blood test results 
  • are well enough to be up and about for at least half the day (performance status 0, 1 or 2
  • are at least 18 years old
  • are willing to use reliable contraception during treatment and for a month afterwards if there is any chance that you or your partner could become pregnant

You cannot join this trial if any of these apply. You:

  • have had chemotherapy that reached your whole body (systemic) or a targeted cancer drug (biological therapy) in the last 3 weeks 
  • have had an experimental treatment or you have taken part in a clinical trial in the last 4 weeks 
  • are known to be sensitive to atovaquone or anything it contains
  • have an inflammation of the liver (hepatitis) that needs treatment   
  • have problems with your gallbladder Open a glossary item or inflammation of the pancreas
  • have problems with your digestive system Open a glossary item and doctors think you won’t be able to absorb atovaquone  
  • have taken warfarin in the past 2 weeks 
  • take or have taken drugs that can change the way atovaquone works such as metformin in the past 2 weeks. Your doctor can tell you more about this    
  • have HIV
  • have hepatitis B or hepatitis C
  • have any other medical condition or mental health problem that the trial team thinks could affect you taking part in this trial 
  • are pregnant or breastfeeding 

Trial design

This is a phase 0 trial. The researchers need about 30 people going to Churchill Hospital in Oxford to take part.

This trial has 2 parts (cohorts). Doctors are currently looking people to join cohort 2. 

Cohort 1 
You have the same surgery as if you were not in the trial. 7 to 17 days before your operation you take atovaquone. It is a liquid you take twice a day, with food. How long you take atovaquone for will depend on when your operation is scheduled. 

16 to 24 hours before your operation you take pimonidazole capsules. This helps show the areas of low oxygen (hypoxia) in the cancer when the researchers look at a sample of it after your operation. 

Cohort 2
You have surgery the same as if you were not in the trial. But before your operation you take pimonidazole capsules for 16 to 24 hours to help show the areas of low oxygen in the cancer. 

Blood tests
You have some extra blood tests as part of this trial. The researchers want to look for markers of low levels of oxygen in the cancer and find out what happens to atovaquone in the body (pharmacokinetics Open a glossary item). 

You have the extra blood samples before the start of treatment. If possible the extra blood samples are done at the same time as any routine blood tests.  

Researchers might ask to store some of your blood samples and use it in future research. 

Research scans
Everyone taking part in this trial has: 

  • a PET-CT scan (if this is suitable for you)
  • a type of CT scan called perfusion CT scan 
  • 2 types of MRI scan

People taking part in cohort 1 have the scans before atovaquone and at the end of treatment. And people in cohort 2 have the scans twice, before surgery. 

Doctors want to look at the levels of oxygen and the amount of blood that goes into the cancer. The scans can take up to 4 hours each time.   

Tissue samples
The research team will look at samples of cancer taken during your surgery. They want to find out if atovaquone has helped to increase the level of oxygen. 

After they have looked at the samples, they might also ask to store the tissue samples and use it in future research. 

Hospital visits

You see the trial team and have some tests before start treatment. The tests might include:

  • physical examination 
  • blood tests 
  • urine test 

After you finish atovaquone you have research scans and blood tests. Then you have surgery. If you are in cohort 2, you also have research scans and blood tests before surgery. The trial team might be able to combine the visits if you prefer. 

The trial team will look at your medical records Open a glossary item after 1 and 2 years. They want to find out how you are getting on and what treatments you have had. 

Side effects

The trial team monitor you during the time you have treatment and you have a phone number to call them if you are worried about anything. The team will tell you about all the possible side effects before you start the trial.

The most common side effects of atovaquone are:

  • feeling sick (nausea)
  • skin rash and itchy skin 

You have a small dose of pimonidazole and the trial team doesn’t think you will have any side effects from this. 

We have information about having a:

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 Geoff Higgins

Supported by

Howat Foundation
Cancer Image Centre Oxford (CICO)
Experimental Cancer Medicine Centre (ECMC)
Oncology Clinical Trials Office (OCTO)
Oxford Clinical Trials Research Unit (OCTRU)
Oxford University Hospitals NHS Foundation Trust 
University of Oxford

Freephone 0808 800 4040

Last review date

CRUK internal database number:


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

Cara took part in a clinical trial

A picture of Cara

"I am glad that taking part in a trial might help others on their own cancer journey.”

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