Inclusion Criteria:

          -  Age 18 years or older

          -  Histologically confirmed metastatic clear cell Renal Cell Carcinoma confirmed by
             imaging and has progressed on/after at least one front-line treatment regimen

          -  Must have archived or fresh tissue biopsy for biomarker testing

          -  Must have radiologic imaging with a computed tomography (CT) scan or magnetic
             resonance imaging (MRI) within 28 days of enrollment

          -  Must have at least one measurable lesion according to RECIST 1.1

          -  ECOG performance status of 0-1

          -  Adequate gastrointestinal (GI), bone marrow, liver and kidney function

          -  Life expectancy minimum of >12 weeks

          -  At least 28 days between termination of prior major surgery or anticancer therapy or
             14 days from last radiation therapy and administration of AVB-S6-500

        Exclusion Criteria:

          -  Received prior treatment with cabozantinib

          -  Concurrent anti-cancer therapy or any other interventional treatment or other
             interventional research trial

          -  Significant cardiac disease history

          -  History of prior malignancy within the past 3 years except adequately treated basal or
             squamous cell skin cancer, superficial bladder cancer or carcinoma in situ of the
             prostate, cervix or breast

          -  Symptomatic CNS metastasis or metastases

          -  Active GI disease that would impact absorption of cabozantinib

          -  Nephrotic range proteinuria at screening

          -  Evidence of active pleural effusion (ie, ascites, anasarca, etc) that requires
             therapeutic intervention within 28 days prior to AVB-S6-500 administration

          -  Has had a major bleed in the last 3 months, uncontrolled hypertension despite
             treatment with Antihypertensives or is not appropriate for treatment with cabozantinib
             in the Investigator's opinion

          -  Serious active infection requiring IV antibiotics and/or hospitalization at study
             entry

          -  Has active, suspected, or previously documented autoimmune disease, defined as
             requiring systemic treatment

          -  Active coronavirus disease 2019, human immunodeficiency virus, Hepatitis B or
             Hepatitis C virus.