 at least one, but no more than two prior chemotherapy regimen for metastatic disease for osteosarcoma, chondrosarcoma and Ewing sarcoma; neo-adjuvant maintenance therapy are not counted towards this requirement. Chordoma not pretreated or with 1 or 2 prior combination chemotherapy regimen or with one or two prior molecularly targeted therapy, but no more than 2 prior lines of treatment whatever the indication can be included. At least 4 weeks since last chemotherapy 6 weeks in case of nitrosoureas and mitomycin C, immunotherapy or any other pharmacological treatment andor radiotherapy; 