. 1.1 Study objectives 1.1.1 Prim ary objectives Dose -finding phase Primary Objective: Outcome Measure: To determine the adult equiva lent exposure/ maximum tolerated dose (MTD) /recommended Phase II (pediatric) dose (RP2D) of durvalumab in co mbinat ion with tremelimumab and durvalumab as monotherapy following combinat ion therapy .Pharmacokinet ics (PK) parameters (including maximum serum concentrati on (Cmax), minimum serum concentration (Cmin), area under the curve (AUC), and others). Time o f RP2D assessment will be at the end of the dose -finding phase, when sufficient numbers of evaluable samples have been accrued. To determine the safet y profile of durvalumab in co mbinat ion with tremelimumab and durvalumab as monotherapy following combinat ion therapy .Adverse events (AEs), vital signs, physical examinat ions, el ectrocardi ograms (ECGs), and laboratory evaluat ions. Dose- expansion pha se Primary Objective: Outcome Measure: To determine the preliminary ant itumor activit y of durvalumab in co mbinat ion with tremelimumab and durvalumab as monotherapy following combinat ion therapy at the recommended dose, using cohort - specific response criteria (e.g. Response Evaluat ion Cri teria in Solid Tumors (RECIST) 1.1).Object ive response rate (ORR) as determined by the Investigator assessed RECIST 1.1 or alternat ive pre- specified tumor-specific response rates for different scoring systems. Assessm ent of antitumor activit y will be specific to tumor cohort. Addit ional efficacy endpo ints that will be collected include DoR, BoR, DCR, PFS, Statistical A nal ysis Pla n St u d y C o de D 4 1 9 E C 0 0 0 0 1 E diti o n N u m ber 4. 0 Date 1 9 A pr 2 0 2 3 C O N FI D E N TI A L A N D P R O P RI E T A R Y 1 1 of 6 5 A P F 1 2, a n d A P F 1 8 base d o n R E CI S T 1.