- Adolescents and young adults (age10 - 40 yoa) with refractory sarcoma, for which there are presently no further treatment options in EURO-Ewing/ EURAMOS/CWS (i.e. ≥ second relapse in ES, resistance to surgery in osteosarcoma, relapsed rhabdomyosarcoma) and have been treated with a combined chemotherapy of trabectedin and irinotecan (described in intervention)