A Pharmacokinetic Interaction Study Between Apatinib Mesylate and Transporter Pgp Substrate Digoxin in Advanced Solid Tumor Subjects

Inclusion Criteria: 1\. Histologically or cytologically confirmed diagnosis of advanced solid tumors. 2. ECOG PS score: 0-1; 3. Expected survival ≥ 3 months; 4. Major organs must function normally, meeting the following criteria: 1. Hematology 1. HB≥100 g/L; 2. ANC≥1.5×109/L; 3. PLT≥90×109/L; 2. Blood biochemistry: 1. TBIL≤ 1.25×ULN; 2. ALT and AST≤2.5×ULN; 3. ALP≤2.5×ULN; 4. Serum Cr ≤ 1.5 × ULN or endogenous CrCl ≥ 60 mL/min (Cockcroft-Gault formula); 5. Albumin \> 30 g/L; 6. K+\>3.0mmol/L; 5. Able to understand and sign an informed consent form (ICF). Exclusion Criteria: 1. Primary liver cancer; gastric cancer; 2. Active brain metastasis (medically uncontrolled), carcinomatous meningitis, spinal cord compression; 3. Presence of clinically symptomatic third space fluid; 4. Uncontrolled hypertension (SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg despite optimal pharmacological treatment); 5. Uncontrolled clinically significant heart disease, including but not limited to the following: (1) \>2 NYHA 2 congestive heart failure; (2) left ventricular ejection fraction (LVEF) \< 50% (3) heart rate \<60 (4) Grade II or greater myocardial ischemia or myocardial infarction(5) QTc interval ≥ 450 ms in males and ≥ 470 ms in females; 6. Abnormal coagulation function; 7. Prior radiotherapy, systemic chemotherapy (\< 6 weeks if chemotherapy including nitrosoureas or mitomycin), hormone therapy, surgery or target therapy within 4 weeks before the study drug administration, or any unresolved AEs \> CTC-AE Grade 1; 8. History of psychotropic substance abuse, alcoholism or drug abuse; 9. Use of study drugs in other clinical trials within 4 weeks prior to the first dose； 10. Use of a potent CYP3A4 inhibitor or inducer within 2 weeks prior to the first dose; 11. Use of any prescription or over-the-counter medication, vitamin products or herbs within 2 weeks before taking the investigational drug; 12. Other factors that may lead to the termination of the participation in the study at the discretion of the investigators.