Zhang D, Damoiseaux R, Babayan L, et al. - Given that current medical therapies for Cushing disease (CD) by and large exert no action on tumor growth, researchers identified drugs that inhibit corticotroph tumor adrenocorticotropic hormone (ACTH) secretion and growth. From a kinase inhibitor library, the dual PI3K/HDAC inhibitor CUDC-907 was identified as a potent inhibitor of murine and human corticotroph tumor ACTH secretion (EC50 1-5nM), and cell proliferation (IC50 5nM). Given its potent efficacy in both in vitro and in vivo CD models, combined with proven safety and tolerance in clinical trials, CUDC-907 may be a promising CD therapy.