This is an open-label, multi-center, dose escalation study in adult subjects with advanced colorectal, gastric, hepatic or pancreatic cancer. The study will evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of SM04755 administered orally. Upon determination of the maximum tolerated dose (MTD), expansion cohorts may be enrolled.

Inclusion Criteria:

• Subjects with advanced colorectal, gastric, hepatic or pancreatic cancer
• Subjects must have recovered from all toxicity associated with previous chemotherapy, targeted therapy, or radiotherapy
• Subjects must meet certain laboratory criteria
• Expected survival > 3months
• Subjects must have no uncontrolled intercurrent illness

Exclusion Criteria:

• Women who are pregnant or lactating, or who are of childbearing potential , and men who do not use a barrier method
• Subjects with significant cardiac issues
• Subjects using certain medications
• Subjects with certain medical conditions
• Subjects with brain metastasis
• Subjects who have recently been enrolled in other experimental clinical trials of investigational agents