Interleukin-15 (IL-15) is a member of the 4-alpha-helix bundle family of cytokines that acts through a heterotrimeric receptor causing potent stimulation of NK and T-cell functions.In addition to expansion, IL-15 stimulated NK cells have increased lytic activity, and their cytotoxicity can be further augmented when combined with targeted antibodies, IL-15 has also been shown to increase ADCC when combined with other antibodies, such as anti-PDL1 antibody, in preclin. models.As rhIL-15 increases Fc-binding effector cell (i.e. NK and CD8 T-cell) number and function, we hypothesized that combining rhIL-15 with avelumab would augment the clin. activity of avelumab by enhancing ADCC in r/r T-cell lymphomas.To test this, we conducted a single-center phase 1 study at the National Cancer Institute (NCT03905135) , the primary aim of the study was to determine the safety and maximum tolerated dose of a continuous i.v. infusion of rhIL-15 in combination with avelumab.The results of this study could also inform efforts to combine immune checkpoint inhibitors with targeted agents in T-cell lymphomas. Ongoing clin. trials of anti-PD1/PDL1 antibodies in combination with targeted agents include combinations with romidepsin, azacitidine, decitabine, and pralatrexate(NCT03278782, NCT04052659, and NCT03240211).