Background:

Radotinib(IY-5511) is a novel and selective Bcl-Abl tyrosine kinase inhibitor. [1]

Bcl-Abl is a constitutively activated chimeric tyrosine kinase which is the genetic abnormality expressed in patient with CML (chronic myeloid leukemia).

In vitro, radotinib couples to Bcr-Abl and reduce the phosphorylation of Bcr-Abl target protein CrkL. The pre-clinical studies shows superiority of radotinib to imatinib in both wild-type and mutant BCR-ABL1 positive CML cell lines. [1]

In a phase I clinical trial, dose up to 1000 mg/day of radotinib exhibits no dose-limiting toxicities. Phase II study proves radotinib to be an effective and well tolerated in chronic phase-chronic myeloid leukemia patients with resistance and/or intolerance to Bcr-Abl1 tyrosine kinase inhibitors. [1]

Reference:
1.  Kim SH, Menon H, Jootar S et al. Efficacy and safety of radotinib in chronic phase chronic myeloid leukemia patients with resistance or intolerance to BCR-ABL1 tyrosine kinase inhibitors. Haematologica. 2014 Jul;99(7):1191-6.