Abstract
Ewing's sarcoma is a devastating rare pediatric cancer of the bone. Intense chemotherapy temporarily controls disease in most patients at presentation but has limited effect in patients with progressive or recurrent disease. We previously described preliminary results of a novel immunotherapy, FANG (Vigil) vaccine, in which 12 advanced stage Ewing's patients were safely treated and went on to achieve a predicted immune response (IFNγ ELISPOT). We describe follow-up through year 3 of a prospective, nonrandomized study comparing an expanded group of Vigil-treated advanced disease Ewing's sarcoma patients (n = 16) with a contemporaneous group of Ewing's sarcoma patients (n = 14) not treated with Vigil. Long-term follow-up results show a survival benefit without evidence of significant toxicity (no ≥ grade 3) to Vigil when administered once monthly by intradermal injection (1 × 10e(6) cells/injection to 1 × 10e(7) cells/injection). Specifically, we report a 1-year actual survival of 73% for Vigil-treated patients compared to 23% in those not treated with Vigil. In addition, there was a 17.2-month difference in overall survival (OS; Kaplan-Meier) between the Vigil (median OS 731 days) and no Vigil patient groups (median OS 207 days). In conclusion, these results supply the rational for further testing of Vigil in advanced stage Ewing's sarcoma.