Phase I Study to Assess Safety of AZD6738 Alone and in Combination With Radiotherapy in Patients With Solid Tumours

Inclusion Criteria: * Histologically or cytologically documented solid tumour refractory to conventional treatment * Evidence of measurable or evaluable disease by RECIST 1.1 * Age must be 18 years or over. * ECOG performance status 0-1 (part A); 0-2 (parts B and C) * Life expectancy of at least 3 months. * Patients must have normal organ and bone marrow function measured within 7 days prior to administration of study treatment as defined below: * Signed informed consent indicating that the subject is aware of the neoplastic nature of their disease and have been informed of the procedures to be followed, the experimental nature of the therapy, alternatives, potential benefits, side effects, risks, and discomforts. * Willing and able to comply with scheduled visits, tissue sampling, treatment plan, and laboratory tests. * Able to swallow, absorb and retain oral medication. Exclusion Criteria: * Therapy with any other investigational medical product (IMP) concurrently or within 28 days prior to signing of consent. * Pregnant or breast-feeding women. * Ability to become pregnant (or already pregnant or lactating). * Clinically significant cardiac disease including: * Known HIV positive or active hepatitis B or C infection * Uncontrolled active infection * Symptomatic and progressive or steroid-requiring brain metastases or leptomeningeal disease involvement. * Uncontrolled hypertension requiring clinical intervention, hypertension requiring 2 or more antihypertensive agents * Dementia or altered mental status that would prohibit informed consent. * Other severe, acute, or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or study drug administration or may interfere with the interpretation of study results and, in the judgment of the Principal Investigator, would make the subject inappropriate for this study.