 The objective of this study is to investigate the safety and tolerability of oral dose of selumetinib in combination with chemotherapies cisplatin and gemcitabine in Japanese patients with advanced biliary tract cancer BTC. In addition, the pharmacokinetic PK profile of selumetinib and chemotherapies will be investigated. Also, the Maximum tolerated dose MTD of selumetinib in combination with chemotherapies for Japanese BTC patients will be identified, if possible. 