CEP-28122 is a highly potent and selective orally active ALK inhibitor with IC50 of 1.9 ± 0.5 nM in an enzyme-based TRF assay. IC50 value: 1.9 ± 0.5 nM Target: ALK in vitro: CEP-28122 is a potent inhibitor of recombinant ALK activity and cellular ALK tyrosine phosphorylation. CEP-28122 also inhibits Flt4 with IC50 of 46 ±10 nM. CEP-28122 induces concentration-dependent growth inhibition/cytotoxicity of ALK-positive anaplastic large-cell lymphoma (ALCL), non-small cell lung cancer (NSCLC), and neuroblastoma cells. [1] in vivo: CEP-28122 displays dose-dependent inhibition of ALK tyrosine phosphorylation in tumor xenografts in mice, with substantial target inhibition (>90%) for more than12 hours following single oral dosing at 30 mg/kg. Dose-dependent antitumor activity was observed in ALK-positive ALCL, NSCLC, and neuroblastoma tumor xenografts in mice administered CEP-28122 orally, with complete/near complete tumor regressions observed following treatment at doses of 30 mg/kg twice daily or higher. [1]