The synthesis and evaluation of novel ALK inhibitors containing the sulfoxide structure

With ceritinib as the lead, a series of novel compounds containing the sulfoxide structure were synthesized and evaluated as anaplastic lymphoma kinase inhibitors. Among them, compounds 18a-d exhibited excellent anti-proliferation activities on H2228 EML4-ALK cancer cell lines with 14-28 nM of the IC₅₀ values. In xenograft mouse models, 18a-d inhibited tumor growth with an excellent inhibitory rate of 75.0% to 86.0% at the dosage of 20 mg kg^-1 as compared to 72.0% of the reference ceritinib. Using 18d as a representative, which exhibited the best in vivo results, we carried out mechanistic studies such as anti-colony formation, induced tumor cell apoptosis, ALK kinase protein phosphorylation in H2228 tumor cells, and molecular docking. All these results indicate that compound 18d is a good anti-tumor lead compound and worthy of further study.