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

To join this study, you would need to be 18 years or older and have non-small cell lung cancer that is locally advanced or has spread (Stage IIIb or IV). A crucial requirement is that your cancer must have a specific genetic change called a 'KRAS mutation,' which will be checked by the study organisers. You would also need to have received one previous course of anti-cancer treatment for your advanced lung cancer, and your cancer must have started to grow again or come back after that first treatment.

There are also some reasons why you might not be able to join. For example, if your lung cancer has a mix of small cell and non-small cell types, or if you've already had more than one anti-cancer treatment for your advanced lung cancer. You also can't have started any new anti-cancer treatment within 30 days before the study begins, and you can't be getting other cancer treatments while on the study (other than steroids). If you've previously been treated with a specific type of drug called an MEK inhibitor or a docetaxel-containing chemotherapy, you wouldn't be eligible, though prior treatment with paclitaxel is allowed.

If you join this study, it's a 'Phase 3' trial, which means it compares a new treatment to a standard one with a dummy pill (placebo). You would be randomly assigned to receive either selumetinib plus docetaxel, or a placebo plus docetaxel – like flipping a coin, so neither you nor your doctor chooses which group you're in. This is also a 'double-blind' study, meaning neither you nor your doctors will know which treatment you are receiving, to keep the results as fair as possible.

You would have regular hospital visits for your IV docetaxel treatment and to take either the selumetinib or placebo pills. During these visits, the study team would perform various checks, including blood tests, scans (like CT scans) to monitor your cancer, and physical exams. You would also be asked to complete questionnaires about how you are feeling and your quality of life. The treatment would continue as long as it's helping and you are tolerating it well. After the treatment phase, there will be follow-up appointments to monitor your health. The total duration of your participation would depend on how your treatment progresses and the follow-up schedule.