A Study to Evaluate the Safety and Pharmacokinetics of Ceralasertib in Combination With Durvalumab in Chinese Patients With Advanced Solid Tumours

Inclusion Criteria: 1. Signed written informed consent. 2. At least 18 years of age at the time of signing the ICF. 3. Histological or cytological confirmation advanced solid tumour with refractory/resistance to a prior line of anti-PD-1/PD-L1-containing therapy (received as monotherapy or in combination) or for which no SoC exists. 4. Ability to swallow oral medication intact and retain it. 5. ECOG/WHO performance status of 0 to 1. 6. Must have a life expectancy of at least 12 weeks. 7. Participant must have had a treatment-free interval of ≥ 3 weeks from any prior therapy before the first dose of study treatment. 8. Body weight \> 35 kg and no cancer-associated cachexia (eg, CTCAE Grade 2 or worse weight loss over the 3 months prior to the Screening Visit). 9. Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. Exclusion Criteria: 1. Inadequate bone marrow reserve or organ function 2. As judged by the investigator, any evidence of uncontrolled intercurrent illness, that in the investigator's opinion makes it undesirable for the participant to participate in the study. 3. Spinal cord compression, leptomeningeal disease, or brain metastases, unless asymptomatic, treated, stable, and not requiring continuous corticosteroids 4. As judged by the investigator, any active disease or condition that will interfere significantly with the absorption, distribution, metabolism, or excretion of oral therapy 5. History of another primary malignancy. 6. As judged by the Investigator, any evidence of severe or uncontrolled systemic diseases, active bleeding diatheses, renal transplant, or active infection including any patient known to have hepatitis B, hepatitis C, and HIV. 7. Known history of HIV infection. 8. Active cardiacvascular disease be consider as clinical significant. 9. Active or prior documented autoimmune or inflammatory disorders 10. Prior exposure to a CHK1 or ATR inhibitor. 11. As judged by the investigator, any unresolved treatment-related toxicities from previous anti-cancer therapy of CTCAE v5.0 Grade ≥ 2 12. Any concurrent chemotherapy, immunotherapy, biologic or hormonal therapy for cancer treatment. 13. Participants must not have experienced a toxicity that led to permanent discontinuation of prior anti-PD-1 or anti-PD-L1 immunotherapy. 14. Participants must not have required the use of additional immunosuppression other than corticosteroids for the management of an AE, not have experienced recurrence of an AE if re-challenged 15. Participants with a known allergy or hypersensitivity to any of the study drugs or any of the study drug excipients 16. Involvement in the planning and/or conduct of the study (applies to both AstraZeneca staff and/or staff at the study site). 17. Judgment by the investigator that the participant should not participate in the study if the participant is unlikely to comply with study procedures, restrictions and requirements. 18. Previous enrolment in the present study. 19. For women only - currently pregnant (confirmed with positive pregnancy test) or breastfeeding.