PTC-028

**PTC-028** is an orally bioavailable small molecule inhibitor primarily targeting **Polycomb complex protein BMI-1**. Mechanistically, it decreases BMI-1 levels through posttranslational hyperphosphorylation, resulting in mitotic cell arrest and apoptosis[1][5][8]. PTC-028 also acts as a **microtubule polymerization inhibitor**, disrupting microtubule dynamics and causing G2/M cell cycle arrest, caspase-dependent apoptosis, and selective anti-tumor activity in cancer models, including ovarian cancer and myelodysplastic syndrome (MDS)[2][3][7]. PTC-028 synergizes with DNA hypomethylating agents (decitabine, azacitidine) and shows efficacy both in vitro and in mouse xenograft models[2][7]. PTC-028 is structurally related to PTC596 and displays activity in multiple preclinical oncology settings.