For more information regarding Bristol-Myers Squibb Clinical Trial participation, please
        visit www.BMSStudyConnect.com

        Inclusion Criteria:

          -  Advanced Gastric Cancer

          -  Must have full activity or, if limited, must be able to walk and carry out light
             activities such as light house work or office work

          -  Must have at least 1 lesion with measurable disease

          -  All participants must have inoperable, advanced, or metastatic EC, GC or GEJ carcinoma
             and have histologically confirmed predominant adenocarcinoma or squamous cell
             carcinoma. (sub protocol C)

        Exclusion Criteria:

          -  Patients/subjects with HER2 positive tumor that have not been treated with trastuzumab
             prior to enrollment

          -  Must not have suspected or known central nervous system metastases unless adequately
             treated

          -  Patients/subjects with autoimmune disease

          -  Patients/subjects who need daily oxygen therapy

          -  Participants who are considered to be refractory or resistant to platinum agents (sub
             protocol c)

          -  Participants who have inability to swallow capsules or pills (sub protocol c)

          -  Current or recent (within 3 months of study treatment administration) gastrointestinal
             disease that could interfere with absorption of orally administered systemic
             treatments (sub protocol c)

          -  Participants with diagnosis or history of myelodysplastic syndrome (MDS) or acute
             myeloid leukemia (AML). (sub protocol C)

          -  Prior treatment with a PARP inhibitor (such as rucaparib, olaparib, niraparib,
             talozaparib, etc.) or a targeted DNA damage response inhibitor (such as ATM or ataxia
             telangiectasia and Rad3-related protein [ATR] inhibitor). (sub protocol C)

        Other protocol defined inclusion/exclusion criteria could apply