4-Acyl Pyrrole Capped HDAC Inhibitors: A New Scaffold for Hybrid Inhibitors of BET Proteins and Histone Deacetylases as Antileukemia Drug Leads.
Schaker-Hubner, L., Warstat, R., Ahlert, H., Mishra, P., Kraft, F.B., Schliehe-Diecks, J., Scholer, A., Borkhardt, A., Breit, B., Bhatia, S., Hugle, M., Gunther, S., Hansen, F.K.(2021) J Med Chem 64: 14620-14646
- PubMed: 34582215 
- DOI: https://doi.org/10.1021/acs.jmedchem.1c01119
- Primary Citation of Related Structures:  
7AXR - PubMed Abstract: 
Multitarget drugs are an emerging alternative to combination therapies. In three iterative cycles of design, synthesis, and biological evaluation, we developed a novel type of potent hybrid inhibitors of bromodomain, and extra-terminal (BET) proteins and histone deacetylases (HDACs) based on the BET inhibitor XD14 and well-established HDAC inhibitors. The most promising new hybrids, 49 and 61 , displayed submicromolar inhibitory activity against HDAC1-3 and 6, and BRD4(1), and possess potent antileukemia activity. 49 induced apoptosis more effectively than the combination of ricolinostat and birabresib (1:1). The most balanced dual inhibitor, 61 , induced significantly more apoptosis than the related control compounds 62 (no BRD4(1) affinity) and 63 (no HDAC inhibition) as well as the 1:1 combination of both. Additionally, 61 was well tolerated in an in vivo zebrafish toxicity model. Overall, our data suggest an advantage of dual HDAC/BET inhibitors over the combination of two single targeted compounds.
Organizational Affiliation: 
Institut für Wirkstoffentwicklung, Medizinische Fakultät, Universität Leipzig, Brüderstraße 34, D-04103 Leipzig, Germany.