Definition

A human immunoglobulin G2 (IgG2) monoclonal antibody against activin receptor-like kinase-1 (ALK-1; ALK1), with potential anti-angiogenic and antineoplastic activities. Upon administration, anti-ALK-1 monoclonal antibody GT90001 targets and binds to ALK-1, and prevents ALK-1 activation by its ligands bone morphogenetic protein 9 (BMP) 9 and BMP10. This prevents ALK-1-mediated endothelial cell signaling and the activation of transforming growth factor-beta (TGF-beta)/TGF-beta receptor I (ALK-5) signaling. This inhibits tumor blood vessel growth, reduces blood flow and angiogenesis and leads to an inhibition of tumor cell proliferation and modulation of the tumor microenvironment (TME). ALK-1 is a type I cell surface receptor and plays a key role in angiogenesis.