MRK-623 (Compound 14k) is a potent, orally active agonist of the GABA A receptor, exhibiting high affinity for subunits α1, α2, α3, and α5 with Ki values of 0.85 nM, 3.7 nM, 4.0 nM, and 0.53 nM, respectively. Notably, MRK-623 demonstrates anxiolytic effects [1].
MRK003 is a γ-secretase inhibitor exhibits promising in vitro pre-clinical activity in multiple myeloma and non-Hodgkin's lymphoma. MRK003 treatment induced caspase-dependent apoptosis and inhibited proliferation of MM and NHL cell lines and patient cells. Examination of signaling events after treatment showed time-dependent decrease in levels of the notch intracellular domain, Hes1 and c-Myc. MRK003 downregulated cyclin D1, Bcl-Xl and Xiap levels in NHL cells and p21, Bcl-2 and Bcl-Xl in MM cells. In addition, MRK003 caused an upregulation of pAkt, indicating crosstalk with the PI3K Akt pathway.