Discovery of Novel 2,4-Diarylaminopyrimidine Analogues (DAAPalogues) Showing Potent Inhibitory Activities against Both Wild-type and Mutant ALK Kinases

We have developed a series of new 2,4-diarylaminopyrimidine analogues (DAAPalogues) bearing a flexible amino acid side chain, different from the majority of the literature reported ALK inhibitors that often possess a structurally constrained arylpiperazine fragment or its equivalents in the solvent-interaction region. Extensive structural elaboration led to compound 15 possessing IC50 values of 2.7 and 15.3 nM, respectively, in the ALK wild-type and gate-keeper mutant L1196M enzymatic assays. This compound not only showed high proliferative inhibition against ALK-addicted cells across different oncogenic forms but also effectively suppressed several ALK secondary mutant cells, including the gate-keeper L1196M and F1174L. Significant antitumor efficacy was achieved in the ALK-driven SUP-M2 xenograft model.