Histone deacetylase inhibitors

Recent Findings on histone deacetylase inhibitors

• Structure-guided HDAC11 inhibitor discovery: A 2026 study used long-timescale molecular-dynamics simulation to support the identification of inhibitors directed against HDAC11, with the objective of developing targeted chemotherapy strategies. The pharmacokinetic properties and drug-likeness of 35 selected HDAC inhibitors were predicted using the SwissADME platform, while toxicity profiles were assessed with Protox-II 42747587Sep. This work extends the field’s movement from general HDAC inhibition toward structure-guided and potentially isoform-selective inhibitor design.

• Combination with HER2-directed antibody–drug conjugates: In preclinical models of HER2-positive breast cancer, the HDAC inhibitor chidamide was combined with an antibody–drug conjugate (ADC). The combination produced synergistic antitumor effects, as did treatment with the collagen-modulating agent losartan 42594874Aug. The study used spatial proteogenomic profiling to investigate the tumor microenvironment and sensitization strategies, placing HDAC inhibition within a combination-treatment framework that also includes breast cancer biology, proteomics, and ADC therapy.

• Neurovascular effects after ischemic stroke: HDAC inhibition was evaluated alongside hypoxia-inducible factor (HIF) activation after ischemic stroke. The study identified HDAC inhibitors such as apicidin and prolyl hydroxylase inhibitors such as dimethyloxalylglycine (DMOG) as promising therapeutic candidates, while emphasizing that their effects on subcellular architecture remained incompletely characterized 42219139May. The reported comparison distinguished neuronal ultrastructural preservation associated with HDAC inhibition from vascular-integrity effects associated with HIF activation.

• HDAC inhibition and immunotherapy-associated lineage plasticity: A case report described a patient with metastatic melanoma whose disease progressed through sequential treatments, including pembrolizumab combined with the HDAC inhibitor entinostat and ipilimumab 42624103Aug. The report examined melanoma-to-rhabdomyosarcoma plasticity in the setting of immunotherapy, linking HDAC inhibition to the broader problem of lineage change and resistance during checkpoint inhibitor treatment. It does not establish the efficacy of the pembrolizumab–entinostat combination in this individual case.

• KBTBD4-mutant cancer vulnerability: High-throughput screening identified HDAC inhibitors as agents that specifically disrupted the activity of mutant KBTBD4. The proposed mechanism involved prevention of the mutant protein’s interaction with the CoREST complex 42576054Aug. These findings connect HDAC inhibition with cancer-associated differentiation defects and suggest that altered chromatin-regulatory dependencies may create genotype-associated therapeutic vulnerabilities.

• Tucidinostat in relapsed or refractory peripheral T-cell lymphoma: A phase IIb analysis evaluated the HDAC inhibitor tucidinostat in relapsed or refractory peripheral T-cell lymphoma (PTCL). The study reported efficacy, particularly in angioimmunoblastic T-cell lymphoma (AITL), while examining whether a T-follicular-helper (TFH) phenotype could predict response across a broader PTCL population 42262647Jun. The absence of TFH phenotyping in earlier patient assessments had limited evaluation of its predictive value.

• Combination with chemotherapy in pancreatic cancer models: A multicenter in-vitro ring test assessed reproducibility in detecting drug synergism in complex pancreatic cancer treatment combinations. The addition of VPA and simvastatin (VPA/SIM) to gemcitabine plus nab-paclitaxel reproducibly enhanced antitumor activity in the tested models 42224741Jun. This result supports further translational evaluation of HDAC-inhibitor-containing combinations in pancreatic ductal adenocarcinoma while also highlighting the importance of standardized methods for combination screening.

• Reprogramming of infantile hemangioma cell fate: A study of infantile hemangioma identified HDAC inhibitors as potential epigenetic drugs for suppressing vasculogenesis. The work focused on HDAC-inhibition-associated reprogramming of stem-cell fate as a mechanism for reducing formation of vascular structures 42240910Jun. This application extends HDAC inhibitor research beyond conventional anticancer models to a vascular proliferative disorder.

• BRCA1- and BRCA2-associated lung adenocarcinoma biology: Molecular profiling of human lung adenocarcinoma examined the tumor microenvironment associated with somatic BRCA1 and BRCA2 mutations. The study reported that a cancer-promoting program activated by BRCA1 mutation was vulnerable to HDAC inhibitors and that HDAC inhibition reduced lung adenocarcinoma tumor growth 42189716May. The findings position HDAC inhibitors as possible agents for targeting mutation-associated transcriptional or microenvironmental programs.

• Acetylation and apoptosis in hepatoma cells: A publication, subsequently marked with an Expression of Concern, reported that HDAC inhibitors induced acetylation of p53 and histones in HepG2 human hepatoma cells, with these changes correlating with apoptotic effects 42169657May. The observation links HDAC inhibition with TP53 and histone acetylation in a hepatoma-cell model; the Expression of Concern is important context when interpreting the reliability and evidentiary status of the reported findings.

• Overall research direction: Across these studies, HDAC inhibitors are being investigated in three connected areas: reprogramming differentiation or immature cell states, refining HDAC-directed therapeutic biology through selective inhibitor design and biomarker analysis, and overcoming treatment resistance through rational combinations. The recent literature includes combinations with ADCs, gemcitabine plus nab-paclitaxel, pembrolizumab, and ipilimumab, as well as studies using high-throughput screening, molecular simulation, spatial proteogenomics, and standardized in-vitro synergy testing.