OncoMed Pharmaceuticals announced that the United States Patent and Trademark Office has granted OncoMed its third broad U.S. patent relating to antibodies that target the RSPO-LGR pathway, which is believed to be an important CSC pathway. The new patent, U.S. Patent No. 8,540,989, covers methods of treating cancer with antibodies that bind human R-spondin, or RSPO, proteins and either disrupt the binding of such proteins to their receptors, the leucine-rich repeat-containing G-coupled receptors, or LGRs, or disrupt RSPO activation of LGR signaling. The new patent is based on key discoveries by OncoMed scientists that RSPO proteins signal through the LGR receptor family and that antibodies that disrupt binding of RSPO proteins to LGRs or that disrupt RSPO activation of LGR signaling are potential anti-cancer agents. OncoMed has identified multiple antibodies targeting the RSPO-LGR pathway and demonstrated the activity of these antibodies in preclinical studies. OncoMed plans to file an Investigational New Drug filing on its first antibody targeting the RSPO-LGR pathway in as early as 2014. OncoMed has worldwide rights to all of its RSPO-LGR pathway programs.