Inclusion Criteria:

- Patients with pathologically confirmed, locally advanced or metastatic solid tumors
who are unresponsive to standard therapy or for whom standard therapy is intolerable
or unsuitable

- Age: ≥21 years (at time of informed consent)

- ECOG performance status: ≤2 (Appendix 1)

- Life expectancy of longer than 3 months

- Adequate vital organ function as follows:

1. Bone marrow function Neutrophils: ≥1,500/μL, platelets: ≥75,000/μL, hemoglobin:
≥9.0 g/dL

2. Hepatic function Aspartate transaminase (AST) and alanine transaminase(ALT):
≤2.5 ×institutional upper limit of normal(ULN) or ≤5.0 × institutional ULN if
there is liver metastasis, serum total bilirubin: <2.5 × institutional ULN

3. Renal function Serum creatinine: <1.5 × institutional ULN

- Capable of swallowing OPB-51602 tablets

- Ability to understand and willingness to sign written informed consent form (ICF) for
participation in the trial

- No chemotherapy, radiotherapy, surgery, immunotherapy, or other therapy within 4
weeks prior to start of investigational medicinal product (IMP) administration and
recovered from any prior toxicity

- If a subject has received more than 5 regimens of previous chemotherapy, the
investigator must discuss with the sponsor regarding subject suitability prior to
enrollment.

Exclusion Criteria:

- Uncontrolled central nervous system (CNS) metastasis

- Uncontrolled concurrent illness, including active infection, angina pectoris, cardiac
arrhythmia, or heart failure (NYHA class III or IV, Appendix 2 New York Heart
Association (NYHA) functional classification)

- Concurrent malignancy of a different type

- Immunocompromised subjects, including those who are known to be infected with human
immunodeficiency virus (HIV)

- Psychiatric illness that would limit compliance with trial requirements

- Pregnant or breast-feeding women

- Women of childbearing potential (WOCBP) or male subjects whose partners are WOCBP who
cannot or will not use effective contraceptive measures

- Administration of another investigational agent within 6 weeks prior to start of IMP
administration

- Use of any of the prohibited medications and other substances listed in Appendix 3
CYP3A4 Inhibitors and Inducers within either 1 week prior to start of IMP
administration or a period of at least 5 times the respective elimination halflife,
whichever is longer

- Known severe gastrointestinal disorder, including malabsorption (at screening)

- Patients with CTCAE Grade 1 or higher pneumonitis (interstitial pneumonia) or
pulmonary fibrosis* * If interstitial lung abnormalities, (e.g. ground-glass or
linear opacity) are suspected on chest CT scan (high-resolution CT), regardless of
whether or not there are any accompanying symptoms it must be confirmed, such as
through consultation with a respiratory or radiology expert if necessary, that the
patient dose not fall under this exclusion criterion before the patient can be
enrolled in the trial.