JAK2 ^V617F Myeloproliferative Neoplasms Support Parallel Evolution of Independent Leukemic Clones

Myeloproliferative neoplasms (MPNs) are hematological diseases predominantly driven by the JAK2 ^V617F mutation. Progression from chronic-phase MPN to secondary acute myeloid leukemia (sAML) is a severe complication that dramatically worsens disease prognosis. While progression to sAML is classically linked to MPN clones acquiring additional mutations, the absence of JAK2 ^V617F in some cases of post-MPN sAML cases suggests alternative mechanisms of transformation. Utilizing patient samples and in vivo modeling, we establish that leukemic clones can emerge independently of JAK2-mutant cells and undergo positive selection in the pro-inflammatory MPN environment, leading to parallel disease evolution. Genetic and pharmacological inhibition of IL-12 and TNFα mitigates this competitive advantage. Our data establish a new paradigm and show that disease progression in MPN can arise from parallel acute myeloid leukemia (pAML) clones.