A Study of Different Dosing Schedules of Selumetinib With Cisplatin/Gemcitabine (CIS/GEM) Versus CIS/GEM Alone in Biliary Cancer

This is a phase II study (the second stage of testing a new drug or new drug combinations) to see how useful two different schedules of study drug selumetinib with cisplatin and gemcitabine are compared to cisplatin and gemticabine alone in patients with biliary cancer. Selumetinib, an oral drug which plays an important role in the regulation of cell growth (MEK 1/2 inhibitor) has been shown to shrink tumours in patients with biliary cancer and other types of human cancers. Selumetinib has also been shown to shrink tumours when given in combination with cisplatin and gemcitabine in research studies done in animals and in some patients with biliary tract cancer. Cisplatin and gemcitabine are intravenous drugs that work by damaging DNA in tumor cells so that they are unable to grow and divide.