NN-390 (NN390) is a potent, selective HDAC6 inhibitor with IC50 of 9.8 nM, >200-550-fold selectivity over other HDAC isoforms.NN-390 inhibits primary cells of treatment-refractory Group 3 MB cells (SU_MB002) with IC50 of 2.33 uM.NN-390 is the first HDAC6-selective inhibitor to show therapeutic potential in metastatic Group 3 medulloblastoma (MB), an aggressive pediatric brain tumor often associated with leptomeningeal metastases and therapy resistance.NN-390 selectively targets cell population with a 44.3-fold therapeutic margin between patient-derived Group 3 MB cells in comparison to healthy neural stem cells.NN-390 demonstrated a 45-fold increased potency over HDAC6-selective clinical candidate citarinostat.
