TAE684 is a potent and selective ALK inhibitor with IC50 of 3 nM, 100-fold more sensitive for ALK than InsR.
TAE684 does not exhibit significant cross-reactivity against other kinases. TAE684 potently inhibits the proliferation of Ba/F3 NPM-ALK cells with IC50 of 3 nM, without affecting the survival of Ba/F3 cells even at 1 μM. TAE684 also inhibits proliferation of NPM-ALK-expressing human ALCL cell lines including Karpas-299 and SU-DHL-1 with IC50 of 2–5 nM. Molecular modeling reveals that L258 may be one of the major kinase-selectivity determinants for TAE684. TAE684 treatment results in a rapid and sustained inhibition of phosphorylation of NPM-ALK. TAE684 induces apoptosis and G1 phase arrest in NPM-ALK-expressing Ba/F3 cells and ALCL patient cell lines.TAE684 markedly overcomes Crizotinib-resistance in H3122 CR cells, harboring the fusion oncogene EML4-ALK, decreasing cell growth, suppressing ALK phosphorylation and inducing apoptosis.Neurite outgrowth induced by expression of the mALK R1279Q mutant could be completely inhibited by TAE684 at 30 nM.
After 4 weeks of treatment with TAE684 at 3 and 10 mg/kg, there is a significant delay in lymphoma development and 100- to 1,000-fold reduction in luminescence signal, without any signs of compound- or disease-related toxicity in Karpas-299 lymphoma model. TAE684 treatment also induces disease regression in established Karpas-299 lymphomas and down-regulates CD30 expression.TAE684 also shows impressive antitumor activity against H3122 CR xenograft tumors.Furthermore, treatment with TAE684 improves the rough eye phenotype of both ALK mutants, especially that seen with ALKR1275Q, whereas Crizotinib has little effect on either phenotype.
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