Pexidartinib (PLX3397),1029044-16-3,IC-0211676

Pexidartinib(PLX3397) is an orally administered small molecule tyrosine kinase inhibitor with potent selective activity against the colony-stimulating factor 1(CSF1) receptor(IC50=20nM), KIT proto-oncogene receptor tyrosine kinase(KIT)(IC50 =10nM) and FMS-like tyrosine kinase 3[1,2]
Pexidartinib was a stronger KIT inhibitor than imatinib in vitro. Compared pexidartinib and imatinib in vitro against 2 human GIST cell lines that harbor an imatinib-sensitive, activating KIT exon 11 mutation. Indeed, pexidartinib decreased viability in both cell lines with two-fold greater potency than imatinib, with an IC50 of 8-18 nM versus 42 nM(p<0.05). At concentrations similar to the IC50 of each drug, i.e., 10 and 40 nM, PLX3397 also decreased phospho-KIT relative to total KIT more effectively than imatinib in vitro[3]
Pexidartinib is effective in reducing adipose tissue macrophage levels of chow and high fat diet mice without affecting total myeloid cell levels[4]. A research found pexidartinib was well-tolerated in non-human primates(NHPs), with no Grade 3 or Grade 4 toxicities. Pexidartinib has limited CSF penetrance in NHPs following oral administration of a single dose[5]
Pexidartinib received its first approval on 2 August 2019 in the USA for the treatment of adult patients with symptomatic TGCT associated with severe morbidity or functional limitations and not amenable to improvement with surgery[2]