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

Inclusion Criteria:

1. Male and female participants at least 18 years of age at the time of signing the informed consent form (ICF).
2. 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).
3. Radiographically measurable or evaluable disease by CT or MRI per RECIST v1.1 criteria.
4. Eastern Cooperative Oncology Group performance status 0 to 1.
5. Documented FGFR2 rearrangement.
6. Willingness to avoid pregnancy or fathering children.

Exclusion Criteria:

1. 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]).
2. Child-Pugh B and C.
3. Toxicities related to prior therapy(ies) must be Common Terminology Criteria for Adverse Events (CTCAE) v5.0 ≤ Grade 1 at the time of screening.
4. Concurrent anticancer therapy, other than the therapies being tested in this study.
5. Participant is a candidate for potentially curative surgery.
6. Current evidence of clinically significant corneal (including but not limited to bullous/band keratopathy, corneal abrasion, inflammation/ulceration, and keratoconjunctivitis) or retinal disorder (including but not limited to central serous retinopathy, macular/retinal degeneration, diabetic retinopathy, retinal detachment) as confirmed by ophthalmologic examination.
7. Radiation therapy administered within 4 weeks of enrollment/randomization/first dose of study treatment.
8. Known central nervous system (CNS) metastases or history of uncontrolled seizures.
9. Known additional malignancy that is progressing or requires active treatment (exceptions: basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or in situ cervical cancer that has undergone potentially curative therapy).
10. Laboratory values at screening outside the protocol-defined range.
11. History of calcium and phosphate hemostasis disorder or systemic mineral imbalance with ectopic calcification of soft tissues (exception: commonly observed calcifications in soft tissues, such as the skin, kidney, tendons or vessels due to injury, disease, and aging, in the absence of systemic mineral imbalance).
12. Significant gastrointestinal disorders that could interfere with absorption, metabolism, or excretion of pemigatinib.
13. Clinically significant or uncontrolled cardiac disease.
14. History or presence of an abnormal ECG, which, in the investigator's opinion, is clinically meaningful.
15. Chronic or current active infectious disease requiring systemic antibiotics or antifungal or antiviral treatment within 2 weeks prior to enrollment (participants with asymptomatic chronic infections on prophylactic treatment are allowed). Note: HIV-positive participants are allowed if all of the following criteria are met: CD4+ count ≥ 300/µL, undetectable viral load, receiving antiretroviral therapy that does not interact with study drug, and no HIV/AIDS-associated opportunistic infection in the last 12 months.
16. Use of any potent CYP3A4 inhibitors or inducers or moderate CYP3A4 inducers within 14 days or 5 half-lives (whichever is longer) before the first dose of study treatment. Note: Moderate CYP3A4 inhibitors are not prohibited
17. Known hypersensitivity or severe reaction to pemigatinib, gemcitabine, cisplatin, or their excipients.
18. Inadequate recovery from toxicity and/or complications from a major surgery before starting therapy.