The purpose of this study is to determine the maximum tolerated dose (MTD), safety, pharmacokinetics (PK), pharmacodynamics (PD) and anti-tumor activity of E7050 when administered orally twice daily to patients with advanced solid tumors.

Phase I, open-label, dose-escalation study to determine the maximum tolerated dose (MTD) of E7050 given orally, twice-daily, in patients with advanced tumors that have progressed following effective therapy.

Inclusion criteria:

1. Subjects with a histological or cytological diagnosis of solid tumors or gastric cancer.
2. Subjects who have progressed after treatment with approved therapies or for whom there are no standard effective therapies available.
3. Subjects with adequate organ function.
4. Patients who have no carryover of effect from prior therapy or no adverse drug reactions (excluding alopecia) that may affect the safety evaluation of the investigational drug.
5. Subjects with Performance Status (PS) 0-1 established by Eastern Cooperative Oncology Group (ECOG).

Exclusion criteria:

1. Subjects who have brain metastases with clinical symptoms or which requires treatment.
2. Subjects with the serious complications or disease history.
3. Subjects who cannot take oral medication.
4. Subjects who need continuous use of drugs or foods that strongly inhibit or induce CYP3A4/5 or CYP2D6 during the study period.
5. Female subjects who are pregnant or breast-feeding.