A Study of an FGFR2/3 Inhibitor (CGT4859) in Patients With Cholangiocarcinoma and Other Advanced Solid Tumors

Key Who May Qualify: 1. diagnosed by tissue sample (biopsy-confirmed) locally advanced, metastatic, and/or unresectable iCCA or other solid tumor with documented FGFR2/3 alteration in blood and/or tumor. 2. Previously treated with, not appropriate for, or declined standard-of-care first-line treatment. 3. Have tumors that can be measured on scans v1.1. 4. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1. 5. Have clinically acceptable local laboratory screening results (clinical chemistry and hematology) within certain limits. 6. Resolution of toxicities from prior therapy to ≤Grade 1 (or baseline), including resolution of clinically significant laboratory abnormalities, before the first dose of study drug. Exceptions are alopecia, hypothyroidism, or type 1 diabetes mellitus controlled with medical intervention, and paronychia controlled with local intervention. Key Who Should NOT Join This Trial: 1. Received chemotherapy or anticancer therapies or radiotherapy within certain timeframes before first dose of study drug. 2. Major surgeries (eg, abdominal laparotomy) within 4 weeks of the first dose of study drug. 3. Clinically significant corneal or retinal disorders or current evidence of retinal detachment. 4. Received more than 2 prior FGFRi therapies 5. Active, symptomatic, or untreated brain metastases unless the participant is clinically stable and off corticosteroids for ≥2 months. Always talk to your doctor about whether this trial is right for you.