Evaluating Efficacy of Tivozanib (AV-951) in Biliary Tract Cancers

Oral tivozanib taken daily for Days 1-21 continuously (of each 28-day cycle) followed with 7 days off medication (except for patients in DL-1, with dosing every other day of the 28-day cycle). Phase I: The starting dose (DL1) is 0.89 mg taken once a day continuously for Days 1-21 with 1 week off medication (except for those patients assigned to DL-1, where tivozanib should be taken every other day, around 48 hours apart in 28-day cycle). Patients may escalate to 1.34 mg taken once a day (DL2) continuously for Days 1-21 with 1 week off medication for their second cycle if there are no dose-limiting toxicities. Phase II: Tivozanib dose level will be at the recommended Phase II dose (RP2D) established in Phase I.