 SAN FRANCISCO, May 18, 2021 PRNewswire -- Nektar Therapeutics Nasdaq: NKTR today announced the publication of preclinical data from its second major immuno-oncology cytokine program, NKTR-255, in the Journal for ImmunoTherapy of Cancer JITC. NKTR-255 is a novel recombinant human Interleukin-15 rhIL-15 receptor agonist designed to activate the IL-15 pathway to expand both natural killer NK cells and memory CD8 T cell populations. 