A Study to Evaluate the Efficacy and Safety of Pemigatinib Versus Chemotherapy in Unresectable or Metastatic Cholangiocarcinoma

Inclusion Criteria: * Male and female participants at least 18 years of age at the time of signing the informed consent form (ICF). * Histologically or cytologically confirmed cholangiocarcinoma that is previously untreated and considered unresectable and/or metastatic (Stage IV per the American Joint Committee on Cancer (AJCC) Cancer Staging Manual). * Radiographically measurable or evaluable disease by CT or MRI per RECIST v1.1 criteria. * Eastern Cooperative Oncology Group performance status 0 to 1. * Documented FGFR2 rearrangement. * Willingness to avoid pregnancy or fathering children. Exclusion Criteria: * Received prior anticancer systemic therapy for unresectable and/or metastatic disease (not including adjuvant/neo-adjuvant treatment completed at least 6 months prior to enrollment, and participants that have received treatment for locally advanced disease with trans-arterial chemoembolization or selective internal radiation therapy, if clear evidence of radiological progression is observed before enrollment, or enrolled as of Amendment 6 (or Amendment 5-JP2) and the participant received 1 cycle of gemcitabine plus cisplatin \[the start of study drug {Cycle 1 Day 1} must be at least 14 days and ≤ 4 weeks {28 days} from the last dose of gemcitabine plus cisplatin\]). * Child-Pugh B and C. * Toxicities related to prior therapy(ies) must be Common Terminology Criteria for Adverse Events (CTCAE) v5.0 ≤ Grade 1 at the time of screening. * Concurrent anticancer therapy, …