Description: PF-06737007 (PF06737007) is a novel, potent, selective, peripherally restricted, efficacious, and well-tolerated pan-Trk inhibitor with anti-hyperalgesic activity. In cell-based assays, it inhibits TRK with IC50s of 7.7 nM, 15 nM and 3.9 nM for TrkA, TrkB and TrkC, respectively. It has anti-hyperalgesic effect. Hormones of the neurotrophin family, nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin 3 (NT3), and neurotrophin 4 (NT4), are known to activate the family of Tropomyosin receptor kinases (TrkA, TrkB, and TrkC). Moreover, inhibition of the TrkA kinase pathway in pain has been clinically validated by the NGF antibody tanezumab, leading to significant interest in the development of small molecule inhibitors of TrkA. Furthermore, Trk inhibitors having an acceptable safety profile will require minimal brain availability.