Protease-activated Interferon Alpha-2b Prodrug CX-801

**Semantic type:** Pharmacologic Substance

**Definition:** A dually-masked, prodrug form of the human cytokine interferon alpha-2b (IFN-alpha-2b), composed of IFN-alpha-2b linked to dual proprietary masking peptides through protease-cleavable linkers, with potential immunomodulatory and antineoplastic activities. Upon administration of protease-activated IFN-alpha-2b prodrug CX-801, the linkage system is stable in the circulation and, upon extravasation into the tumor microenvironment (TME), the peptide mask is cleaved by tumor-associated proteases, and active IFN-alpha-2b is released. IFN-alpha-2b binds to specific IFN cell-surface receptors. This activates IFN-mediated signal transduction pathways and induces the transcription and translation of genes with interferon-stimulated response elements (ISREs); the protein products mediate immunomodulating and antiproliferative effects. The selective activation in the TME enhances the IFN-alpha-2b-mediated immune responses against tumor cells while sparing the unwanted effects of systemic, peripheral immune activation.

**Synonyms:** - CX 801 - CX-801 - CX801 - Dually-masked Interferon Alpha-2b Probody CX-801 - Protease-activated IFN-alpha-2b Prodrug CX-801