Inclusion Criteria:

          1. Signed, informed consent

          2. Age 18 or more years

          3. Histologically or cytologically confirmed, previously treated, locally-advanced or
             metastatic pancreatic ductal adenocarcinoma (PDAC) or other CA19-9 positive
             malignancies

          4. Prior treatment with (or intolerance to) at least one standard systemic regimen for
             the patient's respective tumor

          5. Evidence of tumor expression of CA19-9 based on IHC performed on tumor samples or
             elevated serum levels (≥1.5 x ULN) of CA19-9 considered secondary to tumor

          6. Evaluable or measurable disease based on RECIST 1.1 (50)

          7. Recovered from any prior treatment related toxicity to at least Grade 1 with exception
             of Grade 2 alopecia or other Grade 2 toxicity with prior approval of the Medical
             Monitor

          8. If previously exposed to irradiation, the combined prior and anticipated exposure for
             Cycle 1 is not expected to exceed organ exposure limits outlined in Table 2

          9. ECOG performance status of 0 or 1 (51), or KPS of 100% to 80% (52)

         10. Adequate hematologic, renal and hepatic laboratory parameters

        Exclusion Criteria:

          1. Brain metastases unless previously treated and well controlled for at least 3 months

          2. Any tumor mass greater than 10 cm in longest diameter

          3. Other known active cancer(s) likely to require treatment in the next two (2) years

          4. Active, uncontrolled bacterial, viral, or fungal infection(s) requiring systemic
             therapy

          5. Fewer than 28 days from prior anticancer therapy including chemotherapy, hormonal,
             investigational, and/or biological therapies and irradiation except for:

               1. Ongoing hormonal therapy administered for control of cancer (e.g., breast cancer,
                  prostate cancer), which may be continued throughout the study

               2. MVT-5873 and MVT-2163 administered as part of a different protocol

          6. Major surgery other than diagnostic surgery within 28 days of Study Day 1

          7. History of anaphylactic reaction to human, or humanized, antibody

          8. Pregnant or currently breast-feeding

          9. Known to be positive for HIV, Hepatitis B, or Hepatitis C

         10. Psychiatric illness/social situations that would interfere with compliance with study
             requirements

         11. Significant cardiovascular risk including, but not limited to, recent (within 4 weeks)
             coronary stenting or myocardial infarction within 6 months