Definition

The besylate salt form of clifutinib, an orally bioavailable, selective, small molecule inhibitor of FMS-like tyrosine kinase 3 (FLT3; CD135; STK1; FLK2), with potential antineoplastic activity. Upon oral administration, clifutinib targets, binds to and inhibits the activity of FLT3. This inhibits the proliferation of FLT3-expressing cancer cells. FLT3, a class III receptor tyrosine kinase (RTK), is overexpressed or mutated in most B-lineage neoplasms and in acute myeloid leukemias.