Phase IB Metformin, Digoxin, Simvastatin in Solid Tumors

Inclusion Criteria 1. Subject ≥18 years with histologically confirmed solid tumor. 2. Dose expansion subjects must have at least one tumor mass amenable to core needle biopsy. 3. Refractory or intolerant to established standard of care. 4. Have at least one tumor mass amenable to core needle biopsy. Adequate Archival Tissue required for patients that will take part in the dose escalation cohorts. 5. ECOG performance status (PS) = 0-2, or Karnofsky PS ≥60%, or Lansky PS ≥60%. 6. Normal organ and marrow function: absolute granulocyte count ≥1,000/mm3, absolute lymphocyte count ≥400/mm3, platelets ≥100,000/mm3, total bilirubin ≤ institutional upper normal limit, AST/ASL ≤2x institutional upper limit of normal, GFR \>60 mL/min/1.73 m2 and creatinine \<1.5 mg/dL. 7. Subject has recovered to CTCAE Grade 1 or better from all adverse events associated with prior therapy or surgery. Pre-existing motor or sensory neurologic pathology or symptoms must be recovered to CTCAE Grade 2 or better. 8. If female of childbearing potential, has a negative urine or serum pregnancy test. If the urine test is positive or cannot be confirmed as negative, a negative serum test will then be required for study entry. 9. Ability to understand and the willingness to sign a written informed protocol specific consent. Exclusion Criteria: 1. Anti-cancer chemotherapy, biologic therapy or immunotherapy within 3 weeks or radiation therapy within 2 weeks of first infusion. 2. Known history of other malignancy unless having undergone curative intent therapy without evidence of that disease for ≥ 3 years except cutaneous squamous cell and basal cell skin cancer, superficial bladder cancer, in situ cervical cancer or other in situ cancers are allowed if definitively resected. 3. Patients with only PET non-avid disease. 4. Brain metastases unless treated with curative intent (gamma knife or surgical resection) and without evidence of progression for ≥ 2 months. 5. Known history of rhabdomyolysis. 6. History of or current evidence of any condition (including medical, psychiatric or substance abuse disorder), therapy, or laboratory abnormality that might confound the results of the study, interfere with the subject's participation for the full duration of the study, or is not in the best interest of the subject to participate, in the opinion of the Investigator. 7. Known HIV or chronic Hepatitis B or C infection. 8. Have signs and symptoms consistent with an active infection. 9. Live vaccination for the prevention of infectious disease administered \<30 days prior to the start of study therapy or inactivated vaccination \<14 days prior to the start of study therapy. 10. History of severe allergic, anaphylactic, or other hypersensitivity reactions to Metformin, Simvastatin, and/or Digoxin. 11. Patients diagnosed with Wolff-Parkinson-White Syndrome or electrocardiographic (ECG) pattern. Other cardiac conditions including: Previous MI with evidence of residual electrographic pattern consisted with bradycardia/heart block. Atrio-ventricular (AV) heart block (currently ongoing). History of ventricular fibrillation. Sick Sinus Syndrome or Sinus bradycardia thought to be caused by sinus node disease, unless effectively treated. Heart failure associated with preserved left ventricular ejection fraction, including constructive pericarditis, restrictive cardiomyopathy, and Amyloid heart muscle disease. 12. Women of childbearing potential who are found to be pregnant as evidenced by positive serum pregnancy test (minimum sensitivity 25 IU/L or equivalent units of HCG) or nursing.