Study to Assess MEDI4736 With Either AZD9150 or AZD5069 in Advanced Solid Tumors & Relapsed Metastatic Squamous Cell Carcinoma of Head & Neck

Key Inclusion Criteria: * Male and female patients must be at least 18 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). Indicator lesions must not have been previously treated with surgery, radiation therapy, or radiofrequency ablation unless there is documented progression after therapy. * Has undergone ≤3 previous regimens (depending on treatment arm) of cytoreductive therapies including, but not limited to, platinum-based compounds, taxanes, or 5-fluorouracil. for B7 \& B8, no prior systemic treatments should have been received for RM SCCHN * 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 * Additional inclusion for part A: Has a histological confirmation of a solid malignancy (other than HCC) that is refractory to standard therapy or for which no standard of care regimen currently exists. * Addition inclusion for Part A (A6) Has a histological confirmation of castrate-resistant prostate cancer * Additional inclusion for P…