PF-06439015 is a synthetic compound that acts as a potent inhibitor of receptor tyrosine kinases. It inhibits various tyrosine kinases including ALK, ROS1, FER, LTK and TrkB with IC₅₀ values of less than 10 nM¹.

Tyrosine kinases are a family of enzymes that acts as important mediators of the signaling cascade leading to cell proliferation, differentiation, migration, metabolism, and programmed cell death. Tyrosine kinases catalyze phosphorylation of select tyrosine residues in target proteins².