Assess Safety & Efficacy of Selumetinib When Given in Combination With Standard First Line Treatment for Advanced Non-small Cell Lung Cancer

Inclusion Criteria:

* Provision of signed, written and dated consent prior to any study specific procedures
* Male or female, aged 18 years or older
* Histological or cytological confirmation of locally advanced or metastatic NSCLC (IIIB-IV)
* Female patients must not be breast-feeding and have a negative pregnancy test prior to start of dosing or must have evidence of non-child-bearing potential
* Patients must be eligible to receive treatment with the platinum doublet combination with which selumetinib is being combined and in accordance with the local product information

Exclusion Criteria:

* Prior chemotherapy or other systemic anti-cancer treatment for advanced NSCLC.
* Prior surgery or radiotherapy within 6 months or palliative radiotherapy within 4 weeks of start of study treatment.
* Female patients who are breast-feeding or male or female patients of reproductive potential who are not employing an effective method of birth control
* Another primary malignancy within 5 years of starting study treatment, except for adequately treated basal or squamous cell carcinoma of the skin or cancer of the cervix in situ.
* As judged by the Investigator, any evidence of severe or uncontrolled systemic diseases, active bleeding diatheses, renal transplant, or active infection