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

The dose-escalation Part A of this study will involve patients with advanced solid malignancies refractory to standard therapy or for which no standard of care regimen currently exists. Approximately 30 evaluable patients per treatment arm (A1 or A2) will be enrolled. A3 will test viability of alternate dosing schedule for AZD5069, A4/A5 will evaluate AZD9150/AZD5069 in fixed dose combination with MEDI4736 and tremelimumab in solid tumors. there may also be safety run in cohorts enrolled (A6/A7) in specific solid tumor types (breast and prostate cancer). Once the maximum tolerated doses (MTDs) for each of the 2 agents (AZD9150/AZD5069)in combination with MEDI4736 have been identified or the maximum doses of each of the 2 agents in combination with MEDI4736 have been reached, the dose expansion Part B of the study would commence. It will be conducted in patients with recurrent and/or metastatic (RM) squamous cell carcinoma of the head and neck (SCCHN). Between 68 and 266 eligible patients will be enrolled and will randomly assigned to 1 of the following 6 treatment arms or non randomized arm B7: * Treatment arm B1: AZD9150 in combination with MEDI4736 in patients with prior exposure to anti-PD-(L)1 antibodies * Treatment arm B2: AZD5069 in combination with MEDI4736 in patients with prior exposure to anti-PD-(L)1 antibodies * Treatment arm B3: AZD9150 in combination with MEDI4736 in patients with no prior exposure to anti-PD-(L)1 antibodies (2L RM SCCHN) * Treatment arm B4: AZD5069 in combination with MEDI4736 in patients with no prior exposure to anti-PD-(L)1 antibodies * Treatment arm B5: AZD9150 alone in patients with no prior exposure to anti-PD-(L)1 antibodies * Treatment arm B6: AZD5069 alone in patients with no prior exposure to anti-PD-(L)1 antibodies * Treatment arm B7: (non randomized): AZD9150 in combination with MEDI4736 in patients with no prior exposure to anti-PD-(L)1 antibodies (1L RM SCCHN) * Treatment arm B8: (non randomized): AZD9150 (every two weeks) in combination with MEDI4736 in patients with no prior exposure to anti-PD-(L)1 antibodies (1L RM SCCHN)