This is a Phase Ib, open-label, multicentre study of AZD9291 administered orally in combination with novel therapeutics (AZD6094 or selumetinib (AZD6244, ARRY142886)) to patients with EGFRm+ advanced NSCLC. The study has been designed to allow an investigation of the optimal combination dose and schedule whilst ensuring the safety of patients with intensive safety monitoring. There are three main parts to this study; Part A, Combination dose finding and Parts B and D, Dose expansion. Part C, AZD6094 dose finding sub-study in advanced solid tumour patients is ongoing in Japan.