Feasibility of Treating Adults with Ewing or Ewing-Like Sarcoma with Interval-Compressed Vincristine, Doxorubicin, and Cyclophosphamide Alternating with Ifosfamide and Etoposide.

For Ewing sarcoma, interval-compressed vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide administered every 2 weeks rather than every 3 weeks has been shown to improve event-free survival in pediatric patients. However, in adults, oncologists may be hesitant to pursue interval-compressed therapy because of concerns for feasibility. In the adult population in this study, a median interval between cycles of 15.0 days (mean 17.0 days) was achieved, comparable to the interval achieved in AEWS0031 (median 15.0, mean 17.3 days). Given that this was achieved without unexpected toxicity or substantial dose reductions and that clinical outcomes were favorable compared with adult historical controls, these results support the use of this regimen in adults.