recombinant interleukin-15

Recombinant interleukin-15 (rhIL-15) is a recombinant protein used as an investigational immunotherapeutic agent. It is a synthetic form of human interleukin-15 created through recombinant DNA technology[9]. IL-15 is an endogenous cytokine that stimulates the proliferation and activation of natural killer (NK) cells and CD8+ T cells without inducing T regulatory cell expansion or activation-induced cell death[1][2][5]. Mechanistically, rhIL-15 acts as an agonist of the interleukin-15 receptor, leading to dramatic expansion of NK cells (especially CD56^bright^ subset) and CD8+ T cells, thereby enhancing anti-tumor immune responses[1][2][5]. It is being investigated primarily for cancer immunotherapy (solid tumors, metastatic melanoma, renal cell carcinoma, T-cell leukemias) and as adjunct therapy with checkpoint inhibitors[2][5][4][6][7][8]. Additional preclinical research suggests immune activation and survival benefit in sepsis models due to increased T cell and NK cell counts and IFN-γ production[3]. Clinical administration routes studied include **intravenous, subcutaneous, and inhalation**, with each route affecting pharmacokinetics, efficacy, and tolerability[1][2][5]. The half-life is short (2.5–2.7 h), requiring continuous infusion or repeated dosing to sustain therapeutic serum levels[1][5]. Dose-limiting toxicities include fever, chills, thrombocytopenia, hypotension, and cardiac chest pain[2][5]. No objective responses were seen in monotherapy cancer trials, but disease stabilization and strong immunomodulation were observed, and rhIL-15 is being further tested in combination with other immunotherapies[2][5][8].

Other names

interleukin-15, human recombinanthuman IL-15