635 A novel site-directed chemical conjugation technology confers antitumor activity via native Fc receptor to plasma immunoglobulin by attaching tumor binders by Rajat Varma, Christian Vidal, Michael Cukan, Lawrence Iben, Tanya Berbasova, Ada Vaill, Anna Bunin, Ann Marie Rossi, David Trinh, Katy McGrath, Enrique Alvarez, Matthew Welsch, Luca Rastelli