Inclusion Criteria:

          -  Age ≥18 years.

          -  Have histologically or cytologically - proven adenosquamous carcinoma of the pancreas
             or ampulla.

          -  Has unresectable or metastatic measurable disease.

          -  Has received (or been intolerant to or ineligible for) at least 1 prior line of
             cytotoxic chemotherapy and received no more than 2 prior systemic treatments.

          -  Presence of at least one lesion with measurable disease.

          -  Accept to have a tumor biopsy of an accessible lesion at baseline and on treatment.

          -  Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.

          -  If HIV-positive, then all of the following criteria must also be met: cluster of
             differentiation (CD) 4+ count ≥ 350/μL, undetectable viral load, and receiving highly
             active antiretroviral therapy.

          -  Life expectancy of greater than 3 months.

          -  Patients must have adequate organ and marrow function defined by study-specified
             laboratory tests prior to initial study drug.

          -  Woman of childbearing potential must have a negative pregnancy test and follow
             contraceptive guidelines as defined per protocol.

          -  Men must use acceptable form of birth control while on study.

          -  Ability to understand and willingness to sign a written informed consent document.

        Exclusion Criteria

          -  Known history or evidence of brain metastases.

          -  Has had chemotherapy, radiation, or biological cancer therapy within 14 days prior to
             the first dose of study drug.

          -  Has received an investigational agent or used an investigational device within 28 days
             of the first dose of study drug.

          -  Expected to require any other form of systemic or localized antineoplastic therapy
             while on study.

          -  Has had major surgery within 28 days of dosing of investigational agent, excluding
             minor procedures.

          -  Has received a live vaccine within 28 days prior to the first dose of study drug.

          -  Prior treatment with immunotherapy agents (including, anti-PD-1, anti-PD-L1,
             anti-PD-L2, anti-CTLA4, anti-OX40 and LAG-3 antibodies)

          -  Have used any systemic steroids within 14 days of study treatment.

          -  Hypersensitivity reaction to any monoclonal antibody.

          -  Evidence of clinical or radiographic ascites.

          -  Have clinically significant and/or malignant pleural effusion.

          -  Uncontrolled intercurrent illness including, but not limited to, uncontrolled
             infection, symptomatic congestive heart failure, unstable angina, cardiac arrhythmia,
             metastatic cancer, or psychiatric illness/social situations that would limit
             compliance with study requirements.

          -  History of autoimmune disease requiring systemic immunosuppression within the last 2
             years.

          -  Presence of any tissue or organ allograft, regardless of need for immunosuppression,
             including corneal allograft. Patients with a history of allogeneic hematopoeitic stem
             cell transplant will be excluded.

          -  All toxicities attributed to prior anti-cancer therapy other than alopecia and fatigue
             must have resolved to a grade 1 or baseline before administration of study drug.

          -  Infection with Hepatitis A, B or C.

          -  Patient has a pulse oximetry of <92% on room air.

          -  Patient is on supplemental home oxygen.

          -  Has an unhealed surgical wound or ulcer, or a bone fracture considered non-healing.

          -  Patient has clinically significant heart disease.

          -  Patient is, at the time of signing informed consent, a regular user (including
             "recreational use") of any illicit drugs or other substance abuse.

          -  Unwilling or unable to follow the study schedule for any reason.

          -  Patient has history of non-infectious pneumonitis.

          -  Serum albumin level less than 2.8 g/dL.