Study closed to enrollment

Inclusion Criteria:

• Histologic proof of stage IV melanoma (pathology report confirmation) with plans to initiate therapy with ipilimumab according to Food and Drug Administration (FDA) approved guidelines with multiple lesions such that
  • Two of these lesions are in the same organ and at least one of these two lesions is measurable by CT imaging according to RECIST 1.1 OR
  • Three of these lesions are in different organs and at least one of these 3 lesions is measurable by CT imaging according to RECIST 1.1
• Patient eligible for and will be receiving ipilimumab as standard of care therapy
• At most 2 prior systematic regimens in the metastatic setting
• Absolute neutrophil count (ANC) ≥1500 mL
• Hemoglobin (Hgb) > 10 g/dL
• Platelets (PLT) ≥ 50,000 mL
• Aspartate aminotransferase (AST) ≤ 3 x upper limit of normal (ULN)
• Alkaline phosphatase ≤ 3 x ULN*; *up to 5 x allowed for patients with liver metastases
• Ability to provide informed consent
• Willingness to return to Mayo Clinic Rochester for follow-up
• Life expectancy ≥ 12 weeks
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1 or 2
• For women of childbearing potential, a negative serum pregnancy test ≤ 7 days prior to registration
• Willingness to participate in mandatory imaging studies as well as provide mandatory blood samples for correlative research
• Tumor accessible for biopsy

Exclusion Criteria:

• Uncontrolled or current infection
• Known allergy to 99mTc-HYNIC-IL2 or components
• Any of the following prior therapies with interval since most recent treatment:
  • Chemotherapy ≤ 3 weeks prior to registration
  • Biologic therapy ≤ 3 weeks prior to registration
  • Radiation therapy ≤ 3 weeks prior to registration
• No more than 3 prior systematic regimens in the metastatic setting
• Failure to fully recover from side effects of prior chemotherapy or surgery
• Any of the following, as this regimen may be harmful to a developing fetus or nursing child:
  • Pregnant women
  • Nursing women
  • Women of childbearing potential or their sexual partners who are unwilling to employ adequate contraception (condoms, diaphragm, birth control pills, injections, intrauterine device [IUD], surgical sterilization, subcutaneous implants, or abstinence, etc.)