Pemetrexed in Combination With Erlotinib as a Salvage Treatment in Patients With Metastatic Biliary Tract Cancer (BTC) Who Failed Gemcitabine Containing Chemotherapy: A Phase II Single Arm Prospective Study

Inclusion Criteria:

Provision of a signed written informed consent Age ≥ 20 Histologically or cytologically confirmed carcinoma of biliary tract (intrahepatic, extrahepatic cholangiocarcinoma and gall bladder cancer) Unresectable or metastatic Progression after treatment with first line gemcitabine-based chemotherapy ECOG performance status of 0\~2 Measurable lesion per RECIST 1.1 criteria Expected life expectancy ≥ 3months Adequate marrow, hepatic, renal and cardiac functions

Exclusion Criteria:

Poor performance statue Other primary cancer except properly treated non-melanoma skin cancer, cured cervix carcinoma in situ and other cured solid tumor without evidence of recurrence after 5 years of curative treatment.

Severe co-morbid illness and/or active infections Any other clinical trial therapeutics within 14 days Any anti-cancer therapy within 3 weeks prior to initiation of study treatment (radiotherapy, systemic chemotherapy) CTCAE grade 2 or more adverse events remained except alopecia QTcB \> 480msec or family history of QT prolongation Current heart problem such as: pooly controlled hypertension