YTD005

YTD005 is a novel antibody-drug conjugate targeting the stem cell factor receptor CD117 (KIT), engineered as a conditioning agent for autologous hematopoietic stem cell gene therapy and bone marrow transplantation. It incorporates an antagonistic anti-CD117 monoclonal antibody clone discovered by phage display, is Fc-silent to minimize immune effector function, has a deliberately short serum half-life, and carries a non–cell-permeable cytotoxic payload to restrict off-target toxicity.[1] In non-human primate studies, a single infusion of YTD005 effectively depletes endogenous hematopoietic stem cells and enables durable engraftment of gene-modified cells with stable mixed chimerism for over one year, supporting its development as a targeted, less toxic alternative to conventional myeloablative conditioning regimens.[1]