Pembrolizumab-PET Imaging

Inclusion Criteria:

1. Age ≥18 years.
2. Histologically or cytologically documented locally advanced or metastatic melanoma or NSCLC.
3. Patients must be eligible for treatment with Pembrolizumab. For patients with NSCLC this includes PD-L1 expression (\>1% based on IHC assay) on tumor material.
4. Metastatic lesion(s) (≥1,0 cm) of which a histological biopsy can safely be obtained according to standard clinical care procedures.
5. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.
6. Life expectancy ≥ 12 weeks .
7. Signed Informed Consent Form.
8. Ability to comply with protocol.
9. Measurable disease, as defined by standard RECIST v1.1. Previously irradiated lesions should not be counted as target lesions.
10. Adequate hematologic and end organ function, defined by the following laboratory results obtained within ≤ 14 days prior to 89Zr-pembrolizumab injection:

    * Absolute Neutrophil Count (ANC) ≥ 1500 cells/μL (without granulocyte colony-stimulating factor support within 2 weeks prior to 89Zr-pembrolizumab injection)
    * White Blood Count (WBC) ≥ 2500/μL
    * Lymphocyte count ≥ 500/μL
    * Platelet count ≥ 100,000/μL (without transfusion within 2 weeks prior to 89Zr-Pembrolizumab injection)
    * Hemoglobin ≥9.0 g/dL. Patients may be transfused or receive erythropoietin treatment to meet this criteria.
    * Asparate Aminotransferase (AST), Alanine Aminotransferase (ALT), and alkaline phosphatase ≤2.5 x the Upper Limit of Normal (ULN), with the following exceptions:

      * Patients with documented liver metastases: AST and/or ALT ≤ 5 x ULN
      * Patients with documented liver or bone metastases: alkaline phosphatase ≤ 5 x ULN
    * Serum bilirubin ≤ 1.5 x ULN. Patients with known Gilbert disease who have serum bilirubin level ≤3 x ULN may be enrolled.
    * International Normalized Ratio (INR) and Activated Partial Thromboplastin Time (aPTT) ≤1.5 x ULN. This applies only to patients who are not receiving therapeutic anticoagulation; patients receiving therapeutic anticoagulation should be on a stable dose.
    * Creatinine clearance ≥30 mL/min
11. 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. Any approved anti-cancer therapy, including chemotherapy of hormonal therapy within ≤14 days prior to 89Zr-pembrolizumab injection; the following exceptions are allowed:

   • Hormone-replacement therapy or oral contraceptives.
2. Treatment with any other investigational agent or participation in another clinical trial with therapeutic intent within 28 days prior to the 89Zr-pembrolizumab injection.
3. Malignancies other than melanoma or NSCLC within 5 years prior to 89Zr-pembrolizumab injection, with the exception of those with a negligible risk of metastasis or death treated with expected curative outcome (such as adequately treated carcinoma in situ of the cervix, basal or squamous cell skin cancer, localized prostate cancer treated with curative intent or ductal carcinoma in situ treated surgically with curative intent).
4. Pregnant and lactating women.
5. Symptomatic brain metastasis.
6. History of severe allergic, anaphylactic, or other hypersensitivity reactions to chimeric or humanized antibodies or fusion proteins.
7. Known hypersensitivity or allergy to any component of the pembrolizumab formulation.
8. History of autoimmune disease, including but not limited to myasthenia gravis, myositis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, vascular thrombosis associated with antiphospholipid syndrome, Wegener's granulomatosis, Sjögren's syndrome, Guillain-Barré syndrome, multiple sclerosis, vasculitis, or glomerulonephritis.

   * Patients with a history of autoimmune-related hypothyroidism on a stable dose of thyroid replacement hormone may be eligible for this study.
   * Patients with controlled Type I diabetes mellitus on a stable dose of insulin regimen may be eligible for this study.
9. Positive test for Human Immunodeficiency Virus (HIV).
10. Patients with active hepatitis B (chronic or acute; defined as having a positive hepatitis B surface antigen \[HBsAg\] test at screening) or hepatitis C.

    * Patients with past hepatitis B virus (HBV) infection or resolved HBV infection (defined as the presence of hepatitis B core antibody \[HBcAb\] and absence of HBsAg) are eligible. HBV DNA test must be performed in these patients prior to 89Zr-Pembrolizumab injection.
    * Patients positive for hepatitis C virus (HCV) antibody are eligible only if polymerase chain reaction is negative for HCV RNA.
11. Signs or symptoms of infection within 2 weeks prior to 89Zr-pembrolizumab injection.
12. Major surgical procedure other than for diagnosis within 28 days prior to 89Zr-pembrolizumab injection or anticipation of need for a major surgical procedure during the course of the study.
13. Prior allogeneic bone marrow transplantation or solid organ transplant.
14. Treatment with corticosteroids in an increasing dosage in the 7 days prior to 89Zr-pembrolizumab injection. (A stable or decreasing dosage of ≤ 1,5 mg dexamethasone or ≤ 10 mg prednisolone equivalent is allowed. In addition, inhaled or topical steroids and adrenal replacement doses are permitted in the absence of active autoimmune disease.)
15. Inability to comply with other requirements of the protocol.