Inclusion Criteria:

        Age ≥18 years.

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

          -  Have histologically or cytologically-proven ductal pancreatic cancer.

          -  Have metastatic disease.

          -  Have documented radiographic disease progression after previous systemic chemotherapy
             given in a neoadjuvant, adjuvant, locally advanced or metastatic setting.

          -  Patients with the presence of at least one measurable lesion.

          -  Willing to have to a tumor biopsy.

          -  Life expectancy of greater than 3 months.

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

          -  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.

          -  Had chemotherapy, radiation, or steroids within 14 days prior to study treatment.

          -  Have received any investigational drugs, a live vaccine, any allergen
             hyposensitization therapy, growth factors or major surgery within 28 days prior to
             study treatment.

          -  Require any antineoplastic therapy.

          -  Had surgery within 28 days of dosing of investigational agent.

          -  Has received any prophylactic vaccine within 14 days of first dose of study drug.

          -  History of prior treatment with anti-cxcr4.

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

          -  Patients receiving growth factors including, but not limited to, granulocyte-colony
             stimulating factor (G-CSF), Granulocyte-macrophage colony-stimulating factor (GM-CSF),
             erythropoietin, within 14 days of study drug administration.

          -  Hypersensitivity reaction to any monoclonal antibody.

          -  Evidence of clinical or radiographic ascites.

          -  Have clinically significant and/or malignant pleural effusion.

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

          -  Has an active known or suspected autoimmune disease.

          -  Prior tissue or organ allograft or allogeneic bone marrow transplantation.

          -  All toxicities attributed to prior anti-cancer therapy other than alopecia and fatigue
             must have resolved to grade 1 (National Cancer Institute Common Terminology Criteria
             for Adverse Events [CTCAE], version 5) or baseline before administration of study
             drug.

          -  Infection with HIV or hepatitis B or C at screening.

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

          -  Patient is on supplemental home oxygen.

          -  Has uncontrolled intercurrent acute or chronic medical illness or any use of illicit
             drugs or substance abuse.

          -  Patient is unwilling or unable to follow the study schedule for any reason.

          -  Woman who are pregnant or breastfeeding.

          -  Have rapidly progressing disease, as judged by the investigator.

          -  History of significant, recurrent, unexplained postural hypotension in the last 6
             months.