Vactosertib Hydrochloride is an orally active and ATP-competitive ALK5 inhibitor (IC50: 12.9 nM). It has potently antimetastatic activity and anticancer effect. Vactosertib Hydrochloride also inhibits ALK2 and ALK4 (IC50: 17.3 nM).

ALK5:12.9 nM

Vactosertib inhibits the TGFβ-induced nuclear translocation of Smad2/3 in 4T1 cells and MCF10A cells (IC50: 10-30 nM for Vactosertib on pSmad3 in 4T1 cells). Vactosertib (10-1000 nM; 30 minutes; 4T1 cells) treatment blocks the TGFβ-induced phosphorylation of Smad2 or Smad3 in a dose-dependent manner in 4T1 cells. Vactosertib abrogates TGFb1-induced tumor cell migration and invasion. Moreover, Vactosertib abolishes the TGFβ1-induced effects on genes related to epithelial-to-mesenchymal transition (EMT) [1].

Vactosertib inhibits the epithelial-to-mesenchymal transition (EMT) in both TGFβ-treated breast cancer cells and 4T1 orthotopic-grafted mice. Vactosertib (40 mg/kg; i.p.; every other day; for 10 weeks; MMTV/c-Neu female mice) treatment inhibits Smad/TGFβ signaling, cell migration, invasion, and lung metastasis in MMTV/c-Neu mice. Vactosertib enhances cytotoxic T lymphocyte activity in 4T1 orthotopic-grafted mice and increased the survival time of 4T1-Luc and 4T1 breast tumor-bearing mice [1].