We have designed ROS-activated cytotoxic agents that are active against AML cancer cells. In this study the mechanism and synergistic effects against cells co-expressing the AML oncogenes MLL-AF9 fusion and FLT3-ITD was investigated. The agent had an IC50 value of 1.8±0.3 μM with a selectivity of 9-fold compared to untransformed cells. Treatment induced DNA strand breaks, apoptosis, and cell cycle arrest. Proteomics and transcriptomics revealed enhanced expression of the pentose phosphate pathway, DNA repair, and pathways common to cell stress. Western blotting confirmed repair by homologous recombination. Importantly, RAC1 treatment was synergistic in combination with multiple pathway targeting therapies in AML cells but less so in untransformed cells. Taken together, these results demonstrate that RAC1 can selectively target poor prognosis AML and do so by creating DNA double strand breaks that require homologous recombination.