COLEMAN is an opened prospective monocentric non-randomized study, initiated by the Hospices Civils de Lyon. Population targeted are patients from 18 years old with stage III or IV metastatic melanoma eligible for a metastatic melanoma treatment administered as part of usual care.

The objective is to study the variations of immune infiltrate and cell plasticity before and under immunotherapy or targeted therapy. Two biopsies are done before and one month after the treatment initiation and one blood sample is done after the treatment initiation.

100 patients will be included and followed during 5 years.

Inclusion Criteria:

• Patient age ≥ 18
• Female patients must agree to the use of 2 methods of contraception. For man one method of contraception is needed if if his partner is in childbearing age throughout the study and for at least 5 months after last study treatment administration.
• Patients with metastatic stage III or IV melanoma relapse
• Eligible for a melanoma metastatic treatment indicated and administered as part of usual care
• Patients must be willing and able to undergo cutaneous tumor biopsies (except on the face and folds or lymph node) according to the study protocol
• Patient insured or beneficiary of a health insurance plan
• Patient able to provide informed consent and sign approved consent forms to participate in the study
• Patient accepting the conservation of biological samples and their use for clinical research including genetic research

Exclusion Criteria:

• Hematologic tumours under treatment
• Patients with a documented history of autoimmune pathology
• Ocular melanoma
• Persons placed under the safeguard of justice
• Use of immunosuppressants including corticosteroids 4 weeks before the inclusion