Atovaquone as Tumour HypOxia Modifier

Inclusion Criteria: 1. Suspected NSCLC considered suitable for surgical resection by the lung multidisciplinary team meeting (MDT). 2. At least one measurable lesion (greater than 2.5cm maximal length in any direction) that the investigators consider on routine imaging (CT or PET-CT scan performed in the 60 days prior to consent (older scans may be accepted at the discretion of the Chief Investigator providing the results remain clinically significant)) likely to contain regions of hypoxia. 3. Male or female, Age ≥ 18 years. 4. Eastern Cooperative Oncology Group (ECOG) performance score of 0-2 5. The patient is willing and able to comply with the protocol, scheduled follow-up visits and examinations for the duration of the study. 6. Written (signed and dated) informed consent. 7. Haematological and biochemical indices within given ranges Exclusion Criteria: 1. Previous systemic chemotherapy or biological therapy within 21 days of commencing atovaquone treatment. 2. Treatment with any other investigational agent, or participation in another interventional clinical trial within 28 days prior to enrolment. 3. Known previous adverse reaction to atovaquone or its excipients. 4. Active hepatitis, gallbladder disease or pancreatitis 5. Patients with impaired gastrointestinal (GI) function or GI disease that may significantly alter absorption of atovaquone. 6. Concurrent administration of contraindicated agents in the 14 days prior to starting atovaquone as outlined in section 9.4 and the current atovaquone Summary of Product Characteristics (SmPC). 7. Concurrent administration of warfarin in the 14 days prior to starting atovaquone. 8. Patients taking known inhibitors of the electron transport chain such as Metformin. 9. Other psychological, social or medical condition, physical examination finding or a laboratory abnormality that the Investigator considers would make the patient a poor trial candidate or could interfere with protocol compliance or the interpretation of trial results. 10. Patients who are known to be serologically positive for Hepatitis B, Hepatitis C or HIV (Hepatitis and HIV testing specifically for confirming eligibility for this trial are not required). 11. Pregnant or breast-feeding women or women of childbearing potential unless highly effective methods of contraception are used.