LDK378 is a highly potent inhibitor of anaplastic lymphoma kinase (ALK), which is a receptor tyrosine kinase belonging to the superfamily of insulin receptor, with half maximal inhibitory concentration IC50 of 200 pM. LDK378 also exhibits modest to high inhibition against a panel of other kinases, in which only three kinases with IC50 below 100 nM includes IGF-1R (8 nM), InsR (7 nM) and STK22D (23 nM). In previous studies, LDK378 has been found to inhibit the proliferation of Ba/F3 cells transfected with the NPM-ALK fusion gene and Karpas 299 human non-Hodgkin’s Ki-positivr large cell lymphoma harboring the NPM-ALK fusion gene with IC50 of 22.8 nM and 26 nM.

References:
[1]Chen J, Jiang C, Wang S. LDK378: a promising anaplastic lymphoma kinase (ALK) inhibitor. J Med Chem. 2013 Jul 25;56(14):5673-4. doi: 10.1021/jm401005u. Epub 2013 Jul 9.
[2]Marsilje TH, Pei W, Chen B, Lu W, Uno T, Jin Y, Jiang T, Kim S, Li N, Warmuth M, Sarkisova Y, Sun F, Steffy A, Pferdekamper AC, Li AG, Joseph SB, Kim Y, Liu B, Tuntland T, Cui X, Gray NS, Steensma R, Wan Y, Jiang J, Chopiuk G, Li J, Gordon WP, Richmond W, Johnson K, Chang J, Groessl T, He YQ, Phimister A, Aycinena A, Lee CC, Bursulaya B, Karanewsky DS, Seidel HM, Harris JL, Michellys PY. Synthesis, structure-activity relationships, and in vivo efficacy of the novel potent and selective anaplastic lymphoma kinase (ALK) inhibitor 5-chloro-N2-(2-isopropoxy-5-methyl-4-(piperidin-4-yl)phenyl)-N4-(2-(isopropylsulfonyl)phenyl)pyrimidine-2,4-diamine (LDK378) currently in phase 1 and phase 2 clinical trials. J Med Chem. 2013 Jul 25;56(14):5675-90. doi: 10.1021/jm400402q. Epub 2013 Jun 26.