NCIt definition : An orally available dual endothelin receptor (ETR) antagonist with potential antihypertensive
and antineoplastic activity. Upon administration, macitentan and its metabolites block
the binding of endothelin isoform 1 (ET-1) to type-A and type-B ETR on both the tumor
cells and the endothelial cells in the tumor vasculature. This prevents ET-1 mediated
signaling transduction which may decrease tumor cell proliferation, progression, and
angiogenesis in tumor tissue. ET-1, a potent vasoconstrictor that plays an important
role in inflammation and tissue repair, is, together with its receptors, overexpressed
varyingly in many tumor cell types.;