ImmunoPET With an Anti-CD8 Imaging Agent

Inclusion Criteria: 1. Subjects with histologically confirmed locally advanced or metastatic cancer for the following tumor types * Cancer types other than melanoma; subjects meeting the eligibility criteria as formulated in the MPDL3280A treatment study protocol (MPDL3280A-treatment-IST-UMCG) are eligible for part A or part B1. * Melanoma; subjects eligible to receive standard of care anti-PD1 therapy plus or minus ipilimumab, are eligible for part B2. 2. Tumor lesion(s) of which a histological biopsy can safely be obtained according to standard clinical care procedures. 3. Measurable disease, as defined by standard RECIST v1.1. Previously irradiated lesions should not be counted as target lesions. 4. Signed informed consent. 5. Age ≥18 at the time of signing informed consent. 6. Life expectancy ≥12 weeks. 7. Eastern Cooperative Oncology Group (ECOG) performance status 0-1 8. Ability to comply with the protocol. 9. For female patients of childbearing potential and male patients with partners of childbearing potential, agreement (by patient and/or partner) to use a highly effective form(s) of contraception (i.e., one that results in a low failure rate \[\< 1% per year\] when used consistently and correctly). Exclusion Criteria: 1. Potential subjects with cancer other than melanoma will be excluded from participation in this study if they meet exclusion criteria formulated in the MPDL3280A treatment study protocol (MPDL3280A-treatment-IST-UMCG). 2. Signs or symptoms of infection within 2 weeks prior to anti-CD8 imaging agent injection. 3. Prior immune checkpoint inhibitor treatment, including but not limited to anti-PD1 and anti-PD-L1 therapeutic antibodies. 4. History of severe allergic, anaphylactic, or other hypersensitivity reactions to chimeric or humanized antibodies or fusion proteins 5. Any other diseases, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicates the use of the anti-CD8 imaging agent, or that may affect the interpretation of the results or render the patient at high risk from complications. 6. Pregnant or lactating women.