This study is testing a new medicine, SNV1521, for people with advanced cancers. The researchers want to find out if SNV1521 is safe, well-tolerated, and effective in treating solid tumors. They are investigating different doses in order to find the most effective and safe one. They are also investigating whether it can be combined with other cancer therapies.

Inclusion Criteria:

• Advanced or metastatic solid tumor malignancy
• Evaluable or Measurable disease (RECIST 1.1 Criteria).
• ECOG Performance Status 0 or 1.
• Life expectancy > 3 months

Exclusion Criteria:

• History of other malignancy within the past 2 years
• Prior diagnosis of Myelodysplastic syndrome or Acute Myeloid Leukemia
• Significant cardiovascular disease within 6 months
• Significant gastrointestinal disease
• HIV infection with a CD4+ T-cell count < 200 cells/μL and/or a detectable viral load
• Liver dysfunction