Abstract
Relapsed/refractory Ewing sarcoma prognosis is dreadful, especially for recurrences within the first 2 years after initial diagnosis. It is obvious that there is an urgent need for novel treatment strategies for this dismal situation. NK-92 is an activated NK cell line with high cytotoxicity against malignant cells. Here, we present a relapsed/refractory Ewing sarcoma case who had no response to conventional strategies and recieved intratumoral NK-92 cell injections. We observe that intratumoral injection of NK-92 is safe, has no toxicity and shows preliminary evidence of tumor response in relapsed/refractory Ewing Sarcoma.