Open-label, Single Arm, Tumor Imaging and Dosimetry Study of I-124 PGN650 in Advanced Solid Tumors

Inclusion Criteria 1. Signed informed consent form. 2. Male or female, ≥ 18 years of age. 3. Histologically or cytologically confirmed solid tumors at any stage with at least one lesion (primary, metastatic, or recurrent) ≥ 1.5 cm in diameter documented by CT. If the lesion is located in a lymph node, the shortest diameter of the lymph node must be ≥ 1.5 cm as defined by RECIST 1.1. (Note: See Exclusion Criteria #1.) 4. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2. 5. Adequate baseline hematological and organ function, assessed by laboratory values prior to study treatment as follows: absolute neutrophil count (ANC) \> 1.0 x 109/L; hemoglobin \> 7 g/dL; serum creatinine \< 2 x institutional upper limit of normal (IULN); aspartate transaminase (AST) \< 2.5 x IULN; alanine transaminase (ALT) \< 2.5 x IULN; (if liver metastases are present, ALT and AST \< 5 x IULN); total bilirubin \< 1.5 x IULN. 6. Women of childbearing potential must agree to use adequate contraception (hormonal or barrier method of birth control, abstinence), for the duration of study participation (i.e., from dosing day 1 until study day 8). Should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately. 7. Patient must be willing and able to undergo the imaging studies outlined in the protocol. Exclusion Criteria 1. Only measureable disease (primary or metastatic) is located in or near the thyroid gland, liver, kidney, or urinary bladder. 2. Medical conditions such as ischemic heart or lung disease that may be considered an unacceptable risk. 3. Females who are lactating or pregnant. 4. Persistent acute toxicities from prior anti-cancer therapy. 5. History of hypersensitivity to iodine. 6. Known bladder outlet obstruction. 7. Any condition that would in the Investigator's judgment prevents compliance with the requirements of the protocol. 8. Patients with known history of an autoimmune disease- including but not limited to: celiac disease, Crohn's disease, dermatomyositis, Grave's disease, systemic lupus erythematosus, myasthenia gravis, psoriasis, and rheumatoid arthritis.