Discovery of novel 2-phenylamino-4-prolylpyrimidine derivatives as TRK/ALK dual inhibitors with promising antitumor effects

In order to explore novel TRK and ALK dual inhibitors, a series of 2-phenylamino-4-prolylpyrimidine derivatives were designed, synthesized and evaluated for their in vitro cytotoxicity and enzymatic activities. Delightfully, most compounds were detected moderated to excellent activities in cellular assay. Among them, compound 21 exhibited encouraging cytotoxicity on KM12, H2228 and KARPAS299 cells with IC₅₀ values of 0.86, 0.141 and 0.072 μM. Meanwhile, the performances of 21 in the enzymatic assays were in good accordance with anti-proliferative activity with IC₅₀ values of 2.2, 9.3 and 38 nM towards TrkA, ALK^WT and ALK^L1196M, respectively. Compared with Entrectinib, compound 21 not only ensured the inhibitory activity on TrkA, but also improved the affinity with ALK and ALK^L1196M to a certain extent. Ultimately, the binding model of 21 with TrkA and ALK were ideally established through molecular docking, which further confirmed the SARs analysis.