Cancer Therapeutic TKI Osimertinib-induced Cardiotoxicity Is Driven by HDAC-Dependent Epigenetic Repression and Rescued by Vorinostat

There was only a minimal, transient effect on inflammation, supporting a type I, cell-autonomous cardiotoxic mechanism. Consistent with this, in vitro and in vivo analyses demonstrated suppression of pro-survival ERK/AKT signaling, mitochondrial dysfunction, and activation of intrinsic apoptotic pathways. Given the central role of HDAC activation, we tested whether pharmacologic HDAC inhibition could mitigate osimertinib-induced cardiotoxicity.

Treatment with the FDA-approved HDAC inhibitor vorinostat (SAHA) restored histone acetylation, attenuated p53 activation, reduced cardiomyocyte death, and rescued cardiac function in osimertinib-treated mice. Translational studies in human NSCLC-derived PC9 cells further demonstrated that SAHA enhances osimertinib anti-tumor efficacy while alleviating cardiotoxicity. Collectively, these findings define HDAC-dependent epigenetic repression as a key mechanism underlying osimertinib-induced cardiotoxicity and identify HDAC inhibition as a therapeutically actionable strategy to improve both cardiac safety and cancer treatment efficacy.