Etakafusp Alfa

**Semantic type:** Amino Acid, Peptide, or Protein|Pharmacologic Substance

**Definition:** A recombinant fusion protein comprised of a humanized immunoglobulin G1 (IgG1) antibody targeting the T-cell surface glycoprotein CD8 beta chain (CD8b) linked to an affinity-attenuated interleukin-2 (IL-2) mutein, with potential immunostimulating and antineoplastic activities. Upon administration of etakafusp alfa, the antibody moiety specifically targets and binds to CD8+ T-cells, thereby allowing for the IL-2 mutein moiety to specifically bind to IL-2R and activate IL-2R-mediated signaling in CD8+ T-cells. This enhances cytotoxic T-lymphocytes (CTLs)-mediated cytotoxic immune responses against tumor cells. The IL-2 mutein has a reduced affinity to IL-2 receptor subunit alpha (IL-2Ralpha; CD25) and beta (IL-2Rbeta; CD122), which promotes the selective activation of CD8+ T-cells over natural killer (NK) cells and immunosuppressive regulatory T-cells (Tregs). The IL-2Ralpha/IL-2R beta-mediated activation of NK cells and immunosuppressive Tregs is associated with immunosuppression and adverse effects including vascular leak syndrome (VLS).

**Synonyms:** - AB 248 - AB-248 - AB248 - Anti-CD8 Beta Chain Antibody/Interleukin-2 Mutein Fusion Protein AB248 - Anti-CD8b Antibody/IL-2 Mutein Fusion Protein AB248 - CD8-targeted IL-2 Mutein Immunotherapeutic AB248 - ETAKAFUSP ALFA