Entrectinib (NMS-E628) is found to be exquisitely active in inhibiting the proliferation of a limited number of cell lines: the TRKA-driven colorectal carcinoma cell line KM12 (IC50 of 17 nM), the ALK-dependent ALCL cell lines SU-DHL-1, Karpas-299, SUP-M2 and SR-786 (IC50 of 20, 31, 41, and 81 nM, respectively), the ALK-dependent NSCLC cell line NCI-H2228 (IC50 of 68 nM) and the FLT3-dependent AML cell line MV-4-11 (IC50 of 81 nM). Entrectinib potently blocks proliferation of Ba/F3-TEL-TRKB (IC50 of 2.9 nM), Ba/F3-TEL-TRKC (IC50 of 3.3 nM), and Ba/F3-TEL-ROS1 (IC50 of 5.3 nM) cells, with a high degree of selectivity versus parental Ba/F3 cells or those transformed by nontargeted kinases such as ABL and RET, which are inhibited with IC50s in the range of 2 to 3 μM. Entrectinib significantly inhibits the growth of TrkB-expressing NB cells in vitro, and it significantly enhances the growth inhibition of Irino-TMZ when used in combination.