This is a phase I, open-label study to assess the safety, tolerability, pharmacokinetics and preliminary anti-tumor activity of AZD9150 monotherapy and AZD9150 in combination with durvalumab in Japanese patients with advanced solid malignancies.

Key Inclusion Criteria:

• Male and female patients must be at least 20 years of age.
• Has an Eastern Cooperative Oncology Group (ECOG) PS score of 0 or 1.
• Has measurable disease, defined as at least 1 lesion that can be accurately measured in at least 1 dimension (longest diameter to be recorded) with a minimum size of 10 mm by computerised tomography (CT) scan, except lymph nodes which must have minimum short axis size of 15 mm (CT scan slice thickness no greater than 5 mm in both cases).
• Adequate organ and marrow function
• Female subjects of childbearing potential and male subjects with partners of childbearing potential should ensure use of a highly effective method of birth control as defined in study protocol

Key Exclusion Criteria:

• Spinal cord compression unless asymptomatic and not requiring steroids for at least 4 weeks before the start of study treatment.
• Patients must have completed any previous cancer-related treatments before enrolment.
• Has active or prior autoimmune disease within the past 2 years
• Has active or prior inflammatory bowel disease or primary immunodeficiency
• Undergone an organ transplant that requires use of immunosuppressive treatment
• Abnormalities in rhythm, conduction or morphology of resting 12-lead ECG
• Prior exposure to AZD9150 or any other anti PD (L)1 antibody.