Pioglitazone Did Not Affect PPAR-Γ, STAT5, HIF2α and CITED2 Gene Expression in Chronic Myeloid Leukemia Patients with Deep Molecular Response

Preliminary reports demonstrated that pioglitazone, an antidiabetic drug that is agonist of peroxisome proliferator-activated receptor gamma (PPAR-γ) was able to reduce expression of STAT5 and its downstream targets HIF2α and CITED2, which are key guardians of the quiescence and stemness of chronic myeloid leukemia (CML) leukemia stem cells (LSCs). Leaving quiescence would turn the LSCs more sensitive to imatinib (IM) and cause an erosion of the LSCs. This was demonstrated in vitro and in vivo in CML patients that achieved complete molecular response after pioglitazone use. This was the rational for the design of EDI-PIO trial (Pilot Study of Imatinib Discontinuation in Patients with Chronic Myeloid Leukemia with Deep Molecular Response - Evaluation of Pioglitazone in Treatment-Free Remission) (NCT02852486). In this trial, pioglitazone was given in association with IM, with the aim to pull out the LSCs from the quiescence and sensitizing them to IM effect, increasing treatment-free remission (TFR) rates after treatment interruption.