Detection of Plasmatic Cell-free BRAF and NRAS Mutations : a New Tool for Monitoring Patients With Metastatic Malignant Melanoma Treated With Targeted Therapies or Immunotherapy ( MALT )

During a consultation of follow-up for an advanced malignant melanoma (stage IIIb or IIIC or IV), an investigator presents the study to the patient and give him the note of information and the informed consent. The patient can benefit from a reflexion period of of 7 days. In case of agreement, a first blood draw will take place before initiation of any treatment. Between D15 and D30 a second blood draw will be taken. Then a blood draw will be necessary every two months until recurrence or progression of the disease for a maximum of 22 months.