• 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.