Myeloid/lymphoid neoplasms with FGFR1 rearrangement (also known as 8p11 myeloproliferative syndrome, EMS) is a distinct disease entity in the current WHO classification. These patients frequently (~80%) progress to acute myeloid leukemia (AML) and have a poor outcome with a 5-year survival rate of < 20%. To identify the potential treatment regimen on these patients, the four reagents (Idarubicin, arsenic trioxide, Voxtalisib and Ruxolitinib) were applied on KG-1 cells. Our results showed that the KG-1 cell line was resistant to idarubicin. However, the dual PI3K/mTOR inhibitor Voxtalisib, rather than JAK1/2 inhibitor Ruxolitinib could be effectively against KG-1 cells. Arsenic trioxide (As2O3) combined with Voxtalisib synergistically inhibitted the viability of KG-1 cells. We also found... that the combination treatment more significantly reduced the colony formation, induced apoptosis, decreased Bcl-2 expression, but increased caspase-3 expression as compared to the single drug treatment. Additionally, As2O3 enhanced the effect of Voxtalisib which decreased the phosphorylation of PI3K, AKT and mTOR. These data suggests that Voxtalisib in combination with As2O3 may provide a novel and efficacious therapy regimen for patients with EMS.