Figure 3.

Nintedanib inhibits platelet-derived growth factor receptor (PDGFR), fibroblast growth factor receptor (FGFR), and vascular endothelial growth factor receptor (VEGFR)-2 to impair pulmonary fibrosis. (a) Nintedanib directly antagonizes PDGFR signaling, which is triggered by binding of PDGF or possibly to a lesser extent FGF. Nintedanib inhibits FGFR directly and inhibits its signaling molecule, Src. Inhibition of PDGFR and FGFR decreases proliferation and migration of fibroblasts and myofibroblasts and subsequent extracellular matrix (ECM) deposition. (b) Nintedanib inhibits both VEGFR2 directly and its signaling molecule, Src, to mitigate alveolar hypervascularization and angiogenesis. ⁶⁰