['epithelial ovarian cancer', 'peritoneal cancer', 'fallopian tube cancer']
['entinostat', 'avelumab', 'placebo']

        Inclusion Criteria:

          -  Histologically or cytologically confirmed epithelial ovarian, fallopian tube, or
             peritoneal cancer

          -  Recurrent or progressive disease on or after initial platinum-based chemotherapy

          -  Evidence of measurable disease based on imaging studies within 28 days before the
             first dose of study drug

          -  Previously received at least 3, but no more than 6, lines of therapy including at
             least 1 course of platinum-based therapy

          -  Patient must have acceptable, applicable laboratory requirements

          -  Patients may have a history of brain metastasis provided certain protocol criteria are
             met

          -  Experienced resolution of toxic effect(s) of the most recent prior anti-cancer therapy
             to Grade ≤1 (except alopecia or neuropathy)

          -  Able to understand and give written informed consent and comply with study procedures.

        Exclusion Criteria:

          -  Non-epithelial ovarian carcinomas or ovarian tumors with low malignant potential
             (i.e., borderline tumors)

          -  Another known malignancy that is progressing or requires active treatment (excluding
             adequately treated basal cell carcinoma or cervical intraepithelial neoplasia/cervical
             carcinoma in situ or melanoma in situ). Prior history of other cancer is allowed, as
             long as there is no active disease within the prior 5 years.

          -  Diagnosis of immunodeficiency or receiving systemic steroid therapy or any other form
             of immunosuppressive therapy within 7 days prior to enrollment.

          -  Active autoimmune disease that might deteriorate when receiving an immunostimulatory
             agent

          -  Previously treated with a histone deacetylase inhibitor (i.e., vorinostat, belinostat,
             romidepsin, panobinostat), PD-1/PD-L1-blocking antibody (i.e., atezolizumab,
             nivolumab, pembrolizumab), or a cytotoxic T-lymphocyte associated protein-4 (CTLA-4)
             agent

          -  Currently enrolled in (or completed) another investigational drug study within 30 days
             prior to study drug administration

          -  A medical condition that precludes adequate study treatment or increases patient risk
      