This study consists of two parts. In the dose-escalation part, ASP5878 (orally available novel small-molecule FGFR 1,2,3 and 4 inhibitor, multiple dosing once-a-day (q.d.), multiple dosing twice-a-day (b.i.d.) or 5-day on/2-day off dosing twice-a-day (5on-2off)) is administered to participants with solid tumors in an increasing dose manner, and the tolerability, safety, pharmacokinetics (PK), pharmacodynamics (PD) and efficacy of ASP5878 are evaluated in these participants. Cycle 0 consists of 3 days and Cycle 1 and subsequent cycles consist of 28 days each in the dose-escalation part. In the expansion part, 16mg twice-a-day 5-day on/2-day off dose of ASP5878 (5on-2off) is administered to participants with solid tumors and safety, PK, PD and efficacy of ASP5878 are evaluated. The expansion part starts from Cycle 1 and each cycle consists of 28 days.
The objectives of this study are to determine the tolerability, safety, pharmacokinetics (PK), pharmacodynamics (PD), and efficacy of oral ASP5878 in participants with solid tumors.