CDK4/6-IN-3 is a brain-penetrant CDK4/CDK6 inhibitor (Kis: <0.3 nM and 2.2 nM) used for the treatment of glioblastoma. It inhibits CDK1 with a Ki of 110 nM.
Ribociclib hydrochloride is a highly specific CDK4/6 inhibitor (IC50: 10 nM and 39 nM, respectively). It is over 1,000-fold less potent against the cyclin B/CDK1 complex.
Ribociclib succinate hydrate is a highly specific CDK4/6 inhibitor (IC50s: 10 nM and 39 nM, respectively). It also is over 1,000-fold less potent against the cyclin B/CDK1 complex.