KLS-3020

KLS-3020 is an engineered oncolytic vaccinia virus developed by Kolon Life Science for the treatment of solid tumors. The virus is derived from a wild-type vaccinia backbone with the deletion of three specific viral genes—C11R (vaccinia growth factor homolog), K3L (eIF2α homolog), and J2R (thymidine kinase)—to enhance tumor-selective replication and safety. KLS-3020 is further modified to express three therapeutic transgenes: PH20 (a hyaluronidase that degrades the tumor extracellular matrix to facilitate viral spread), sPD1-Fc (a soluble PD-1 fusion protein that acts as a checkpoint inhibitor by blocking the PD-1/PD-L1 pathway), and Interleukin-12 (IL-12, a cytokine that promotes Th1 immune responses and T-cell activation). Preclinical studies in mouse models of melanoma, colon cancer, and lung cancer have demonstrated that the combination of these three transgenes works synergistically to suppress tumor growth and enhance antitumor immunity.