RecruitingPhase 2Drug trialEfficacy of Regorafenib Combined With Best Supportive Care as Maintenance Treatment in High Grade Bone Sarcomas PatientsThis is a multicenter phase II study concerning patients with high-grade bone sarcoma (HGBS) without complete remission after standard treatment at diagnosis or at relapse. Patients will be treated with regorafenib + best supportive care (BSC) for a maximum of 12 months as maintenance therapy after standard line therapy completion. Progression free rate (PFR) data will be collected and analysed for all included patients to evaluate if regorafenib + BSC can be considered as an interesting treatment for further investigations in this indication.