ALKS 4230: a novel engineered IL-2 fusion protein with an improved cellular selectivity profile for cancer immunotherapy.
Lopes, J.E., Fisher, J.L., Flick, H.L., Wang, C., Sun, L., Ernstoff, M.S., Alvarez, J.C., Losey, H.C.(2020) J Immunother Cancer 8
- PubMed: 32317293 
- DOI: https://doi.org/10.1136/jitc-2020-000673
- Primary Citation of Related Structures:  
6VWU - PubMed Abstract: 
Interleukin-2 (IL-2) plays a pivotal role in immune homeostasis due to its ability to stimulate numerous lymphocyte subsets including natural killer (NK) cells, effector CD4 + and CD8 + T cells, and regulatory T cells (T regs ). Low concentrations of IL-2 induce signaling through the high-affinity IL-2 receptor (IL-2R) comprised of IL-2Rα, IL-2Rβ, and common γ chain (γ c ), preferentially expressed on T regs . Higher concentrations of IL-2 are necessary to induce signaling through the intermediate-affinity IL-2R, composed of IL-2Rβ and γ c , expressed on memory CD8 + T cells and NK cells. Recombinant human IL-2 (rhIL-2) is approved for treatment of metastatic melanoma and renal cell carcinoma (RCC), but adverse events including capillary leak syndrome, potentially mediated through interaction with the high-affinity IL-2R, limit its therapeutic use. Furthermore, antitumor efficacy of IL-2 may also be limited by preferential expansion of immunosuppressive T regs . ALKS 4230 is an engineered fusion protein comprised of a circularly-permuted IL-2 with the extracellular domain of IL-2Rα, designed to selectively activate effector lymphocytes bearing the intermediate-affinity IL-2R.
Organizational Affiliation: 
Research, Alkermes, Inc, Waltham, Massachusetts, USA.