Inclusion Criteria:

          -  Participants must have histologically or cytologically confirmed pancreatic
             adenocarcinoma that is metastatic or unresectable. In the dose expansion phase, the
             tumor must express Androgen Receptor (AR) by immunohistochemistry. If ≥1% of the tumor
             cells express AR, it will be considered positive for this trial.

          -  Must have measurable disease per Response Criteria in Solid Tumors (RECIST) criteria
             version 1.1

          -  Eastern Cooperative Oncology Group (ECOG) performance status <2 (Karnofsky >60%)

          -  Life expectancy of greater than 3 months

          -  Must have normal organ and marrow function

          -  Prior treatment with gemcitabine alone or 5-Fluorouracil with radiation as an adjuvant
             therapy will be allowed; Should not have received gemcitabine within 6 months of
             starting the study treatment; 5-Fluorouracil or radiation treatment should be received
             more than 4 weeks prior to receiving the study drug.

          -  Women of child-bearing potential and men must agree to use adequate contraception
             prior to study entry and for the duration of study participation. Men treated or
             enrolled on this protocol must also agree to use adequate contraception prior to the
             study, for the duration of study participation, and 4 months after completion of the
             study treatment.

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

        Exclusion Criteria:

          -  Prior treatment with any cytotoxic chemotherapy except as an adjuvant therapy.
             Participant should not have received gemcitabine within 6 months of starting the study
             treatment. 5-Fluorouracil or radiation treatment should be received more than 4 weeks
             prior to receiving the study drug.

          -  May not be receiving any other investigational agents within 4 weeks of starting the
             study treatment and during the study period.

          -  Untreated brain or leptomeningeal metastases, including patients who continue to
             require glucocorticoids for brain or leptomeningeal metastases.

          -  History of allergic reactions attributed to compounds of similar chemical or biologic
             composition to gemcitabine, nab-paclitaxel or enzalutamide.

          -  Have undergone major surgery within 4 weeks prior to starting the study treatment.

          -  Uncontrolled intercurrent illness including, but not limited to ongoing or active
             infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
             arrhythmia, or psychiatric illness/social situations that would limit compliance with
             study requirements; history of myocardial infarction within 6 months of starting study
             treatment.

          -  Known history of human immunodeficiency virus (HIV) infection or active hepatitis B or
             hepatitis C

          -  Any history of seizure. History of loss of consciousness or transient ischemic attack
             within 12 months of starting the study drug.

          -  Women who are pregnant or breast feeding, or women/men able to conceive and unwilling
             to practice an effective method of birth control

          -  Chronic treatment with immunosuppressant drugs

          -  Other malignancy requiring active treatment

          -  Any significant medical condition, laboratory abnormality, or psychiatric illness,
             that would prevent participating in the study, including the inability to swallow
             capsules

          -  Any active infection not controlled by antibiotics

          -  Concomitant medications that lower seizure threshold