Also available in 1 mL, 2 mg, 5 mg, 10 mg, 25 mg, 100 mg, 200 mg, 500 mg and bulk. Please contact Fisher for quotes. Ribociclib succinate (LEE011 succinate) is a highly specific CDK4/6 inhibitor with IC50 values of 10 nM and 39 nM, respectively, and exhibits over 1,000-fold reduced potency against the cyclin B/CDK1 complex. Purity 99.9%