Definition

A humanized monoclonal antibody directed against the WNT antagonist dickkopf homolog 1 (DKK1), with potential anti-osteolytic activity. Upon administration, sirexatamab binds to and inhibits DKK1, thereby restoring signaling through the WNT pathway, which may result in osteoblast differentiation and activation within the bone matrix and the reversal of tumor-induced osteolytic disease. DKK1, overexpressed by certain cancer cells, is an inhibitor of the WNT signaling pathway and prevents the mediated formation of bone.