CUDC-101 is a potent multi-targeted inhibitor against HDAC, EGFR and HER2 with IC50 of 4.4 nM, 2.4 nM, and 15.7 nM, and inhibits class I/II HDACs, but not class III, Sir-type HDACs. Phase 1.
Specific for class I and class II HDACs, CUDC-101 does not inhibit class III Sir-type HDACs. CUDC-101 displays weak activity against other protein kinases including KDR/VEGFR2, Lyn, Lck, Abl-1, FGFR-2, Flt-3, and Ret with IC50 of 0.85 μM, 0.84 μM, 5.91 μM, 2.89 μM, 3.43 μM, 1.5 μM, abd 3.2 μM, respectively. CUDC-101 displays broad antiproliferative activity in many human cancer cell types with IC50 of 0.04-0.80 μM, exhibiting a higher potency than erlotinib, lapatinib, and combinations of vorinostat with either erlotinib or lapatinib in most cases. CUDC-101 potently inhibits lapatinib- and erlotinib-resistant cancer cell lines. [1] CUDC-101 inhibits the erlotinib-resistant EGFR mutant T790M although its effects are incomplete with an Amax of ~60% of peak enzyme activity after inhibition. CUDC-101 treatment increases the acetylation of histone H3 and H4, as well as the acetylation of non-histone substrates of HDAC such as p53 and α-tubulin, in a dose-dependant manner in various cancer cell lines. CUDC-101 also suppresses HER3 expression, Met amplification, and AKT reactivation in tumor cells. [2]
