Ewing’s sarcoma is a rare cancer that can occur in the bones or soft tissues. It’s more common in children and teens than in adults, but it accounts for only around 1% of childhood cancer cases. Only about 30% of patients with Ewing’s sarcoma are over age 20, and the disease tends to be even more difficult to treat in these cases.

Although many patients with Ewing’s sarcoma are cured with traditional chemotherapy, there haven’t...