Apatinib-d 8 (free base) is the deuterium labeled Apatinib free base. Apatinib free base (YN968D1 free base) is an orally bioavailable tyrosine kinase inhibitor, which selectively targets VEGFR-2 (IC50=1 nM). Apatinib free base (YN968D1 free base) is an anti-angiogenic drug for the research of advanced or metastatic gastric cancer. Apatinib free base (YN968D1 free base) potently inhibits Ret , c-Kit and c-Src with IC50s of 13, 429 and 530 nM, respectively. It also inhibits cellular phosphorylation of VEGFR-2, c-kit and PDGFRβ.