NCIt definition : An orally bioavailable inhibitor of the tyrosine kinase BCR-ABL fusion oncoprotein,
with potential antineoplastic activity. Upon oral administration, BCR-ABL inhibitor
TGRX-678 specifically targets and binds to the myristate site at the C-terminal of
the kinase domain, which results in the cross-linking of SH3 and SH2 domains to the
kinase domain, and locks the kinase in its inactive state. This inhibits the activity
of BCR-ABL, including the T315I gatekeeper residue mutation. The binding results in
the inhibition of BCR-ABL-mediated proliferation and enhanced apoptosis of Philadelphia
chromosome-positive (Ph ) hematological malignancies. The BCR-ABL fusion protein tyrosine
kinase is an abnormal enzyme produced by leukemia cells that contain the Philadelphia
chromosome. The T315I mutation, the most common BCR-ABL mutation, shows resistance
to nearly all commonly used tyrosine kinase inhibitors (TKIs).;