Patients and Methods
toxicity
DISEASE
This open‐label, non‐randomized, phase 2 trial enrolled patients ≥12 years with relapsed EWS. All patients had molecular confirmation of EWS and RECIST measurable disease. Patients initially received palbociclib 125 mg orally on Days 1–21 and ganitumab 18 mg/kg intravenously on Days 1 and 15 of a 28‐day cycle. The primary endpoints were objective response (complete or partial) per RECIST and toxicity by CTCAE. An exact one‐stage design required ≥4 responders out of 15 to evaluate an alternative hypothesis of 40% response rate against a null of 10%. The study was closed following enrollment of the 10th patient due to discontinuation of ganitumab supply.