| abstract |
The present invention relates to a piperazine amide derivative represented by formula (I) or a pharmaceutically acceptable salt thereof, and a pharmaceutical composition thereof, and their use as therapeutic agents, in particular as selective kinase inhibitors during rearrangement transfection (RET), wherein the definitions of a ring, e ring, X1, X2, X3, X4, R1, R2, R3, R4, R<SP>4'</SP>, R5, R<SP>5'</SP>, R6, R<SP>6'</SP>, R7, R<SP>7'</SP>, R8, m and n are the same as those in the description. |