Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Results from the ATOM clinical trial at the University of Oxford have shown that the anti-malarial drug Atovaquone can reduce very low oxygen tumour environments. This has the potential to make cancers behave less aggressively and to improve the impact of everyday cancer treatments.

Atovaquone molecule ball

Cancers metabolise a large amount of oxygen in order to create the energy needed to divide, grow and spread rapidly. This results in oxygen-starved, or ‘hypoxic’, environments around tumour cells.

This proves problematic as hypoxic tumours behave more aggressively and are more resistant to most treatments, especially radiotherapy. Radiotherapy relies on oxygen to attack cancer cells, and previous studies have shown that three-times higher doses of radiation are needed to destroy tumours in hypoxic environments, compared to those in oxygen rich environments.

Researchers from the University of Oxford and Oxford University Hospitals Trust have investigated the potential for the commonly used anti-malarial and pneumonia drug Atovaquone to improve lung tumour receptiveness to cancer treatments such as chemotherapy and radiotherapy.

The ATOM study, published today in Clinical Cancer Research, administered Atovaquone to patients with non-small cell lung cancer before the surgical removal of their tumours. Using state-of-the-art scans to measure tumour hypoxia, this study found that tumours had 55% less hypoxic volumes than those who didn’t receive the drug.

Following genetic analysis, it was shown that Atovaquone successfully disrupted the metabolic pathways of the tumour that are involved in the consumption of oxygen to create energy for tumour cells. The drug successfully reprogrammed the tumour cell metabolism so that more oxygen was present around the tumour, making it more susceptible to treatments.

Atovaquone is a highly-promising clinical drug, as it is already in wide circulation in the prevention and treatment of malaria. As an FDA-approved drug that is cheap and has hardly any side effects, it could be quickly adopted into clinical use if shown to improve the impact of cancer treatments such as radiation therapy. Laboratory experiments have shown its effect is not lung cancer-specific and it is likely to decrease the hypoxic environment of many types of tumour and so may improve treatment outcomes for many different cancer patients

Professor Geoff Higgins, Consultant Oncologist at the Oxford University Hospitals Trust and lead researcher of this University of Oxford project said;

“Although radiotherapy is already an extremely effective treatment, there is scope to further increase its ability to cure patients. Reprogramming a cancer cell to make it more receptive is one way of doing this.

“I’m delighted that the results from the study are so positive so that we can take the next step towards repurposing a well-established drug as a new, effective anti-cancer treatment.”

Professor Higgins’s team are now investigating the potential of this drug further in a study called the ARCADIAN trial. In this study they hope to demonstrate the safety of using Atovaquone in combination with chemotherapy and radiotherapy, before assessing whether combining this drug with such treatments improves survival of patients with lung cancer.

This study was led by Geoff Higgins, Professor at the Department of Oncology, University of Oxford, and Consultant Clinical Oncologist at the Oxford University Hospitals Trust. It was funded by the Howat Foundation, who support translational research for the benefit of cancer patients.

 

Similar stories

Oxford gets £122m funding for healthcare research

Health and care research in Oxford is to receive £122 million in government funding over the next five years to improve diagnosis, treatment and care for NHS patients. The funding was awarded to the city’s two National Institute for Health and Care Research (NIHR) Biomedical Research Centres (BRC).

The Department represented at the European Radiation Research Society annual conference

Researchers from the Department of Oncology attend the prestigious European Radiation Research Society (ERRS) in annual conference in Catania, Italy to present their research in Radiation Oncology.

Funding to research metformin’s ability to delay or prevent cancers driven by the mutated TP53 gene

A research project embedded within the Metformin in Li Fraumeni (MILI) trial will investigate metformin’s mechanism of action when taken as a preventative for mTP53-driven cancers.

Cancer patients remain at higher risk of severe COVID-19 disease despite third dose booster vaccine

A large population-level assessment reveals third dose COVID-19 vaccination is effective for most patients with cancer, but effectiveness is lower than in the general population, particularly in patients who have undergone recent chemotherapy and those with lymphoma.

Time-varying nature of clinical risk factors for pancreatic cancer may aid earlier diagnosis

Body mass index, blood tests, comorbidities and medication use are temporally associated with cancer risk in the three years before a pancreatic cancer diagnosis.

Population-scale study highlights ongoing risk of COVID-19 in some cancer patients despite vaccination

COVID-19 vaccination is effective in most cancer patients, but the level of protection against COVID-19 infection, hospitalisation and death offered by the vaccine is less than in the general population and vaccine effectiveness wanes more quickly.