KA-6859

KA-6859 is a conditionally active bispecific antibody targeting CD19 and the co-stimulatory receptor 4-1BB (CD137). Developed using the proprietary KY-HC-mouse™ platform, it consists of low-affinity anti-4-1BB nanobodies formatted into an Fc-silenced (LALA mutation) IgG framework that targets CD19. The molecule is designed to minimize systemic toxicity, such as hepatotoxicity, by requiring high-avidity cross-linking via CD19 binding on tumor cells to trigger potent 4-1BB signaling. Preclinical data in lymphoma models demonstrate that KA-6859 effectively inhibits tumor growth, particularly when combined with T-cell engagers like glofitamab, and possesses a favorable pharmacokinetic profile suitable for both intravenous and subcutaneous administration.

Other names

CD19×4-1BB bispecific antibodyCD19×CD137 bispecific antibody