NKTR-255 + rituximab

**NKTR-255 + rituximab** is an investigational combination therapy currently in clinical trials for hematologic malignancies, specifically relapsed/refractory non-Hodgkin's lymphoma and multiple myeloma[1][3][5]. **NKTR-255** is a polyethylene glycol-modified recombinant human interleukin-15 (IL-15) receptor agonist designed to stimulate the proliferation and function of CD8+ T cells and natural killer (NK) cells, thereby enhancing anti-tumor immunity and improving the efficacy of monoclonal antibodies such as rituximab[1][6]. **Rituximab** is a monoclonal antibody targeting CD20 expressed on B cells, leading to their depletion via antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. The rationale behind combining the two agents is that NKTR-255’s immune-stimulatory effects may synergistically improve the anti-cancer effect of rituximab by increasing the number and activity of immune effector cells needed for rituximab's anti-tumor mechanism[1][6]. This combination is being assessed for safety, tolerability, and efficacy, with trials including patients who have relapsed or failed CAR-T therapy[6].