Definition

A bispecific ligand-drug conjugate targeting two as of yet undisclosed receptors and conjugated to a topoisomerase inhibitor, with potential antineoplastic activity. Upon administration of bispecific ligand-drug conjugate CBP-1019, the bispecific ligand moiety targets and binds to one or both of the two as of yet undisclosed receptors expressed in certain tumor types. After internalization of the agent, the topoisomerase inhibitor inhibits DNA topoisomerase activity, thereby inhibiting DNA replication which results in cell cycle arrest and tumor cell apoptosis. This inhibits the proliferation of cancer cells expressing the receptor(s).