This is a Phase I/IIa study evaluating the safety and feasibility of [89Zr]Df-IAB2M as an immunoPET tracer for metastatic prostate cancer. Individuals participating in this study will have a FDG PET scan, as well as four (4) PET scans (over a 3 day period) following the injection of [89Zr]Df-IAB2M PET tracer. Three different dosing levels will be explored. The purpose of the study is to demonstrate the safety of [89Zr]Df-IAB2M, ability to detect prostate cancer, and optimal time point and dose level for imaging.

IAB2M is an approximately 80 kDA molecular weight antibody fragment (a "Minibody"). Limited (Phase 0/Proof-of-concept) patient experience with this biologic targeting agent has been previously obtained with SPECT imaging Ex-US, demonstrating targeting of soft tissue and bone lesions in advanced metastatic prostate cancer.

Inclusion Criteria:

• Adult male >/= 18 years of age

• Patients with histologically confirmed prostate cancer

• Progressive disease manifest (within 6 weeks of screening) by either

  • imaging modalities (bone scan, MRI or CT) OR
  • biochemical progression (PSA)

• Performance status of 60 or higher on Karnofsky scale

• Subject's schedule permits compliance with all study procedures

• Ability to understand and willingness to sign a written informed consent form

Exclusion Criteria:

• Previous anaphylactic reaction to huJ591 antibody or FDG imaging
• On any new anticancer therapy (GnRH analog allowed) while on the study
• Hepatic lab values: Bilirubin>1.5 ULN; AST/ALT >2.5 ULN; Albumin < 2 g/dL; GGT > 2.5 ULN if Alkaline Phostphatase >2.5 ULN
• Renal lab values: Creatinine > 1.5 ULN
• Other severe acute or chronic medical condition that may increase the risk associated with study participation or investigational product administration