Optimization of the Time and Dosage of Trametinib in BRAF Negative Juvenile Patients

Lack of mutations in the BRAF gene in tumor tissues and/or circulating tumor DNA (ctDNA) at any stage of treatment or follow-up, or failure of Vemurafenib treatment in BRAF positive patients.

Progression on the I and/or II line treatment, including at least one risk organ; prior treatment should include a minimum of 6 weeks of weekly Vinblastine with a minimum of 28 days prednisolone or minimum 2 cycles of Cytosine Arabinoside in 4-day cycles and/or Cladribine in 5-day cycles as a 2nd line treatment, minimum 2 cycles, or other second-line treatment or

Disease reactivation after an initial response to treatment with Vimblastine and prednisolone as the first line and/or no response to second line treatment using one of two drugs: Cytosine Arabinoside in 4- day cycles and/or Cladribine in 5-day cycles, minimum 2 cycles, or other I/ II line treatment or occurrence of involvement of at least one risk organ or

Signing of informed consent for trial participation (including for Trametinib treatment) according with current legal regulations.