POINTING: Clinical Cohort Study of Patients With Melanoma and NSCLC Receiving Checkpoint Inhibitors

Inclusion criteria: 1. Histologically or cytological documented locally advanced or metastatic melanoma or NSCLC. 2. Patients must be eligible for standard treatment with anti-PD-1 antibody treatment (monotherapy or in combination with other checkpoint inhibitors). 3. Age ≥18 years. 4. Measurable disease, as defined by standard RECIST v1.1. Previously irradiated lesions should not be counted as target lesions. 5. Metastatic or locally advanced lesion(s) of which a histological biopsy can safely be obtained according to standard clinical care procedures. 6. Ability to comply with protocol. 7. Signed Informed Consent form. Exclusion Criteria: 1. Malignancies other than melanoma or NSCLC within 5 years prior to inclusion, 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). 2. Treatment with systemic immunosuppressive medications (including but not limited to prednisone, cyclophosphamide, azathioprine, methotrexate, thalidomide, and anti-tumor necrosis factor agents) within 2 weeks prior to study inclusion. * Patients who have received acute, low-dose, systemic immunosuppressant medications may be enrolled. * The use of inhaled corticosteroids for chronic obstructive pulmonary disease, mineralocorticoids (e.g. fludrocortisone) for patients with orthostatic hypotension, and low-dose supplemental corticosteroids for adrenocortical insufficiency are allowed.