CT680: This phase I/II trial is evaluating an oral drug (TAS-120) in patients with an advanced solid cancer or Multiple MyelomaA Dose-Finding Phase 1 Study of TAS-120 in Patients With Advanced Solid Tumors With or Without Fibroblast Growth Factor/Receptor (FGF/FGFR)-Related Abnormalities Followed By A Phase 2 Study in Patients With Advanced Solid Tumors or Multiple Myeloma With FGF/FGFR-Related Abnormalities

Inclusion

1. Provide written informed consent
2. Age ≥ 18 years of age
3. Has histologically or cytologically confirmed, locally advanced or metastatic cancer

4. The following specific criteria for each study portion

   Phase 1 (Dose Escalation):

   • Patients with any type of solid tumor
   • Disease progression following standard therapies or intolerant to prior standard therapies

   Phase 1 (Dose Expansion)

   • Have at least one FGF/FGFR aberration
   • Disease progression following standard therapies or were intolerant to prior standard therapies (including prior FGFR inhibitors).
   • Have measurable disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST) guidelines (version 1.1, 2009) for advanced solid tumors or RANO criteria (2010) for brain tumors.

   • Patients with any of the following tumor types

     • Patients with intrahepatic or extrahepatic CCA harboring FGFR2 gene fusions or other FGFR2 aberrations
     • Patients with primary CNS tumors
     • Patients with advanced urothelial carcinoma with FGFR3 fusions or FGFR3 activating mutations
     • Patients with breast cancer or gastric cancer
     • Patients with other solid tumor types harboring FGFR gene fusions or activating mutations
     • Patients with solid tumor types and other FGF/FGFR alterations not listed above

   Phase 2

   • Patients with iCCA and FGFR2 gene rearrangements (incl fusions)
   • Have been treated with at least one prior systemic gemcitabine and platinum-based chemotherapy
   • Must have documentation of radiographic progression of disease
   • No prior FGFR inhibitor
   • Measurable disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST) guidelines (version 1.1, 2009)
5. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
6. Adequate organ function.