Inclusion Criteria:

          -  Age 18 years or older

          -  Histologically confirmed and documented recurrent ovarian, fallopian tube, and
             peritoneal cancer.

          -  Platinum resistant disease, defined as progression within ≤ 6 months from completion
             of most recent regimen and calculated from the date of the last administered dose of
             platinum therapy

          -  Must have available archived tumor tissue OR if archived tissue is not available,
             willing to provide a fresh tumor biopsy

          -  Must have radiologic imaging with a computerized tomography (CT) scan or magnetic
             resonance imaging (MRI) within 4 weeks of first dose of study drug

          -  Received at least 1 but not more than 3 therapy regimens, not including maintenance or
             adjuvant therapy

          -  Must have ovarian cancer that is measurable according to RECIST 1.1

          -  ECOG performance status of 0-1

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

          -  At least 28 days between termination of prior anti-cancer or hormonal therapy and
             administration of AVB-S6-500

        Exclusion Criteria:

          -  Primary platinum-refractory disease (defined as progression during the first platinum
             regimen or within 4 weeks of completion of the first platinum regimen)

          -  Currently being treated with concurrent anti-cancer therapy or any other
             interventional treatment or trial

          -  Received prior therapy with Pac or PLD in the recurrent setting, depending on
             physician-chosen chemotherapy for this study

          -  Significant cardiac disease history

          -  Has other prior or concurrent malignancy within the past 5 years except adequately
             treated basal cell skin cancer or carcinoma in situ of the cervix

          -  Symptomatic CNS metastasis or metastases

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

          -  Has known previous or current human immune deficiency (HIV) syndrome, hepatitis B, or
             hepatitis C

          -  Has had paracentesis for ascites within 3 months