Assess Efficacy & Safety of Selumetinib in Combination With Docetaxel in Patients Receiving 2nd Line Treatment for v-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) Positive NSCLC

Overall Survival (OS)

Overall Survival is defined as the time from the date of randomisation until death due to any cause.

Time frame: Measured at baseline until date of death due to any cause. Estimated final completion : approximately 3.5 years after FSI

Objective Response Rate (ORR)

ORR is defined as the number (%) of subjects with at least one overall visit response of complete response (CR) or partial response (PR). Per RECIST v1.1 for target lesions and assessed by CT/MRI: CR - disappearance of all target lesions; PR - \>=30% decrease in the sum of the longest diameter of target lesion. (Non-target lesion and new lesion results are also taken into account for the overall visit result)

Time frame: Measured at baseline until the date of first documented objective disease progression. Estimated final completion : approximately 3 years after first subject in (FSI)

Duration of Response (DoR)

Duration of response is defined as the time from the date of first documented response until the date of objective disease progression (RECIST 1.1) or death (by any cause in the absence of progression)

Time frame: Measured at baseline until the date of first documented objective disease progression. Estimated final completion : approximately 3 years after first subject in (FSI)

Symptom Improvement Rate Using Average Symptom Burden Index (ASBI) of the Lung Cancer Symptom Scale (LCSS)

The symptom improvement rate will be defined as the number (%) of patients with two consecutive assessments at least 18 days apart (ie 21 days allowing a visit window of 3 days) which showed a clinically meaningful improvement in symptoms from baseline (defined as a decrease in the ASBI from baseline ≥10). LCSS-Lung Cancer Symptom Scale; ASBI-Average symptom burden index.

Time frame: Measured from date of randomisation until 30 days post treatment discontinuation or 30 days post progression (if study treatment is discontinued before progression). Estimated final completion : approximately 3 years after first subject in (FSI)

Time to Symptom Progression Using Average Symptom Burden Index (ASBI) of the Lung Cancer Symptom Scale (LCSS)

Time to symptom progression will be defined as the time from randomization until the date of first clinically meaningful symptom deterioration (defined as an increase in the ASBI from baseline ≥10), or death (by any cause). LCSS-Lung Cancer Symptom Scale; ASBI-Average symptom burden index.

Time frame: Measured from date of randomisation until 30 days post treatment discontinuation or 30 days post progression (if study treatment is discontinued before progression). Estimated final completion : approximately 3 years after first subject in (FSI)