The activity of BCY6033 was evaluated in EphA2 expressing EGFR mutant PDX models, DFCI-161 and DFCI-220 in NSG mice….BCY6033 treatment led to significant tumor growth inhibition with >80% tumor regressions in both DFCI-161 and DFCI-220 PDX models. Re-challenge of tumor out-growth showed that they retain sensitivity to BCY6033 treatment.