This is a prospective single arm phase II study to evaluate potential prognostic and/or predictive biomarkers in patients with metastatic ccRCC undergoing treatment with 1st line sunitinib on a 4/2 schedule followed by axitinib on 2nd line therapy.

In this study, all included patients will receive sunitinib until disease progression and/or limiting toxicity. If patients develop toxicities ≥ Grade 2 on 50 mg per day 4 weeks-on / 2 weeks-off schedule, a modified schedule of 50 mg/day 2 weeks-on / 1 week-off will be offered. After disease progression on sunitinib, all eligible patients will receive axitinib 5 mg twice a day. The investigators plan to assess, by next generation sequencing, the prevalence of mutations in several cancer related genes in baseline archived tissue from the patients included in the study, and the potential correlations between these somatic mutations and anti-VEGF (Vascular Endothelial Growth Factor) therapy efficacy.

Inclusion Criteria:

• Diagnosis of Locally advanced (defined as disease not amenable to curative surgery or radiation therapy) or metastatic RCC (equivalent to Stage IV RCC according to American Joint Committee on Cancer staging) renal cell carcinoma;
• Histologic confirmed clear cell renal cell carcinoma;
• No prior systemic therapy (interleukin-2, interferon-α, chemotherapy, bevacizumab, sunitinib, sorafenib, pazopanib, axitinib, everolimus or temsirolimus) for advanced or metastatic RCC;
• Measurable disease by RECIST;
• Eastern Cooperative Oncology Group (ECOG) Performance Status 0 to 2;
• Adequate organ system functions;
• Patients must understand and be willing to sign the written informed consent form of this study.

Exclusion Criteria:

• Non-clear cell renal cell carcinoma

• Pregnant or lactating female.

• History of another malignancy. Note: Subjects who have had another malignancy and have been disease-free for 3 years, or subjects with a history of completely resected non-melanoma skin carcinoma or successfully treated in situ carcinoma are eligible.

• History or clinical evidence of central nervous system (CNS) metastases. Note: Subjects who have previously-treated CNS metastases (surgery ± radiotherapy, radiosurgery) and meet all 3 of the following criteria are eligible:

  1. Are asymptomatic
  2. No evidence of active CNS metastases for ≥3 months prior to enrolment
  3. Have no requirement for steroids or anticonvulsants

• Clinically significant gastrointestinal abnormalities including, but not limited to:

  1. Malabsorption syndrome
  2. Major resection of the stomach or small bowel that could affect the absorption of study drug
  3. Active peptic ulcer disease
  4. Inflammatory bowel disease
  5. Ulcerative colitis, or other gastrointestinal conditions with increased risk of perforation
  6. History of abdominal fistula, gastrointestinal perforation, or intraabdominal abscess within 28 days prior to beginning study treatment.

• History of any one or more of the following cardiovascular conditions within the past 12 months:

  1. Cardiac angioplasty or stenting
  2. Myocardial infarction
  3. Unstable angina
  4. Symptomatic peripheral vascular disease
  5. Class III or IV congestive heart failure, as defined by the New York Heart Association (NYHA)
  6. History of cerebrovascular accident including transient ischemic attack (TIA).
  7. Poorly controlled hypertension [defined as systolic blood pressure (SBP) of ≥150 millimeters of mercury (mmHg) or diastolic blood pressure (DBP) of ≥ 90 mmHg](streamdown:incomplete-link)