SENL-B19

SAN FRANCISCO, Nov. 9, 2022 /PRNewswire/ -- Nektar Therapeutics (Nasdaq: NKTR) today announced the publication of preclinical data in Blood Advances, the open-access journal of the American Society of Hematology, highlighting the effects of NKTR-255, a novel polymer-conjugated human IL-15, on the efficacy of human CD19 CAR-T cells in a xenogeneic lymphoma model and on CD8+ T effector cell (Tcell) and natural killer (NK) cell proliferation in non-human primates. "The findings published today reinforce the foundational rationale behind the clinical development program we're pursuing of NKTR-255 enhancing CAR-T cell therapies," said Jonathan Zalevsky, Ph.D., Chief Research & Development Officer at Nektar. "We are looking forward to progressing our research in combination with cell therapies and are excited to launch our Phase 2/3 clinical trial of NKTR-255 following approved CAR-T cell therapies in patients with relapsed or refractory diffuse large B-cell Lymphoma." The data from this publication demonstrate that NKTR-255 not only enhanced in vivo proliferation and accumulation of T and NK cells in non-human primates, but also demonstrated enhanced in vivo antitumor efficacy of human CD19 CAR-T in lymphoma-bearing immunodeficient mice. "In contrast to mice treated with CAR-T alone, those that received CAR-T and NKTR-255 had markedly higher CAR-T counts in blood and marrow that were sustained after tumor clearance, without evidence of persistent proliferation or ongoing activation/exhaustion assessed by Ki-67 and inhibitory receptor co-expression," said Dr. Cameron Turtle, senior author on the publication and CLEARbridge Chair of Cancer Immunotherapy at Sydney Medical School. "These data support the ongoing clinical research of combined CAR-T and NKTR-255 for B-cell malignancies." Key findings are summarized below: Serum IL-15 concentration is independently associated with longer CD19 CAR-T persistence in humans NKTR-255 promotes CD8+ effector and memory T and NK cell accumulation in non-human primates NKTR-255 enhances proliferation and survival of human CD19 CAR-T at low target cell abundance NKTR-255 enhances accumulation and efficacy of human CD19 CAR-T in lymphoma bearing immunodeficient mice The full citation of this article can be accessed at: https://ashpublications-org.libproxy1.nus.edu.sg/bloodadvances/article/doi/10.1182/bloodadvances.2022008697/486976/A-novel-polymer-conjugated-human-IL-15-improves. About NKTR-255 NKTR-255 is a biologic that targets the IL-15 pathway in order to activate the body's innate and adaptive immunity. Through optimal engagement of the IL-15 receptor complex, NKTR-255 is designed to enhance functional NK cell populations and formation of long-term immunological memory, which may lead to sustained and durable anti-tumor immune response. Preclinical findings suggest NKTR-255 has the potential to synergistically combine with antibody-dependent cellular cytotoxicity molecules as well as to enhance CAR-T therapies. There are two ongoing investigator sponsor trials evaluating NKTR-255 following treatment with a CAR-T cell therapy. Fred Hutchinson Cancer Center is conducting a Phase 1 study evaluating NKTR-255 in combination with CD19 CAR-T cell therapy in patients with relapsed or refractory large B-cell lymphoma (NCT05359211), and Stanford University is conducting a Phase 1 study evaluating NKTR-255 in combination with CD19/22 CAR-T cell therapy in patients with relapsed or refractory B-cell acute lymphoblastic leukemia (NCT03233854). Nektar is also currently designing a Nektar-sponsored Phase 2/3 study combining NKTR-255 with approved CAR-T cell therapies in diffuse large B-cell lymphoma, which it aims to initiate in the first quarter of 2023. About Nektar Therapeutics Nektar Therapeutics is a biopharmaceutical company with a robust, wholly owned R&D pipeline of investigational medicines in oncology and immunology as well as a portfolio of approved partnered medicines. Nektar is headquartered in San Francisco, California, with additional operations in Huntsville, Alabama. Further information about the company and its drug development programs and capabilities may be found online at http://www.nektar.com.