We examined the functional effects of fusion proteins and the efficacy of tyrosine kinase inhibitors in mouse pre-B cells and xenografts of human Ph-like ALL....Cell lines and human leukemic cells expressing ABL1, ABL2, CSF1R, and PDGFRB fusions were sensitive in vitro to dasatinib, EPOR and JAK2 rearrangements were sensitive to ruxolitinib, and the ETV6–NTRK3 fusion was sensitive to crizotinib.

Both patients with JAK2 rearrangements showed an overall reduction in JAK2 rearranged colonies (&x003C7;2 test; case 1, P<0.02; case 2, P<0.05). In case 1, complete eradication of PCM1-JAK2 positive colonies at 500 nM ruxolitinib was seen.