Ewing Sarcoma is a cancer of bone or soft tissue that occurs in children and adults. Treatment usually includes chemotherapy, surgery and/or radiation therapy. This is an international clinical trial (INTER-EWING-1) that will assess multple combinations of these treatment types to determine whether different combinations are better able to improve survival for people with Ewing Sarcoma.

Eligible participants may enter into one of three different treatment arms, depending upon which inclusion criteria they meet. A researcher will assess eligible participants to determine which treatment arm they are most suitable for, and patients will then be randomly allocated by chance into one of two groups for that treatment arm.

Treatment Group A will receive a new chemotherapy drug over 9 cycles.

Treatment Group B will receive doses of radiation therapy which may differ depending upon whether they are able to undergo surgical removal of their cancer or not. Participants will be asked to attend a maximum of 36 sessions over 7.2 weeks.

Treatment Group C will receive either additional doses of a currently used chemotherapy drug, or will be asked to stop their treatment after the standard treatment cycles have been given.

If participants are eligible fo rmore than one of these treatment groups they can choose to enrol in a second and then third treatment group once they have completed their first allocated treatment.