PET Imaging Using 64Cu-Tz-SarAr and hu5B1-TCO in People With Pancreatic, Colorectal, Bladder Cancer or Cancers With Elevated CA19.9

Inclusion Criteria:

Patients will be eligible for enrollment if they fulfill the following criteria:

1. Signed informed consent
2. 18 years of age or older
3. Histologically confirmed primary or metastatic pancreatic ductal adenocarcinoma/bladder carcinoma / gastrointestinal tumor reviewed at MSK - includes patients with biopsy-proven or high suspicion on imaging for pancreatic ductal adenocarcinoma (PDAC) or histologically confirmed, locally-advanced, or metastatic pancreatic ductal adenocarcinoma (PDAC) of

Patient with solid tumors increased serum CA19-9 serum level greater than ULN or CA19-9 positive biopsy

4\. At least one lesion by CT or MRI ≥ 2 cm unless determined otherwise for presurgery subjects 5. ECOG performance status of 0 to 2 6. Adequate laboratory parameters including: i. Absolute neutrophil count (ANC) ≥1.5 x 109/L ii. Hemoglobin ≥ 9.0 g/dL iii. Platelet count \>75,000/ mm3 iv. AST/SGOT, ALT/SGPT ≤2.5 x ULN, unless liver metastases are clearly present, then ≤5.0 x ULN v. Total bilirubin ≤ 1.5x the upper limit of normal unless considered due to Gilbert's syndrome in which case, ≤3x the upper limit of normal vi. Creatinine clearance (CLcr) (\> 60 mL/min) estimated by the Cockcroft-Gault (C-G) equation or estimated glomerular filtration rate (eGFR) 10. Willingness to participate in collection of pharmacokinetic samples

Exclusion Criteria:

Patients will be excluded from the study if they fulfill any of the following criteria:

1. Active, uncontrolled bacterial, viral, or fungal infection(s) requiring systemic therapy
2. Major surgery other than diagnostic surgery within 4 weeks of Study Day 1
3. History of anaphylactic reaction to human, or humanized, antibody
4. Other on-going cancer therapy with investigational agents
5. Known history of HIV
6. Pregnant or currently breast-feeding

   a. Subjects and their partners with reproductive potential must agree to use an effective form of contraception during the study and for 1 week following the study treatment.
7. Psychiatric illness/social situations that would interfere with compliance with study requirements.