Phase I Trial of N-803, an IL15 Receptor Agonist, with Rituximab in Patients with Indolent Non-Hodgkin Lymphoma
Jennifer A. Foltz, Brian Hess, Veronika Bachanová, Nancy L. Bartlett, Melissa M. Berrien-Elliott, Ethan McClain, Michelle Becker‐Hapak, Mark P. Foster, Timothy Schappe, Brad S. Kahl, Neha Mehta–Shah, Amanda F. Cashen, Nancy D. Marín, Kristen McDaniels, Chaz Moreno, Matthew Mosior, Feng Gao, Obi L. Griffith, Malachi Griffith, Julia A. Wagner, Narendranath Epperla, Amy D. Rock, John Lee, Allegra A. Petti, Patrick Soon‐Shiong, Todd A. Fehniger
Abstract
PURPOSE: T cells. Monoclonal antibodies (mAbs) direct Fc receptor-bearing immune cells, including NK cells, to recognize and eliminate cancer targets. The ability of IL15R agonists to enhance tumor-targeting mAbs in patients has not been reported previously. PATIENTS AND METHODS: Relapsed/refractory patients with indolent non-Hodgkin lymphoma were treated with rituximab and intravenous or subcutaneous N-803 on an open-label, dose-escalation phase I study using a 3+3 design (NCT02384954). Primary endpoint was maximum tolerated dose. Immune correlates were performed using multidimensional analysis via mass cytometry and cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) which simultaneously measures protein and single-cell RNA expression. RESULTS: This immunotherapy combination was safe and well tolerated and resulted in durable clinical responses including in rituximab-refractory patients. Subcutaneous N-803 plus rituximab induced sustained proliferation, expansion, and activation of peripheral blood NK cells and CD8 T cells, with increased NK cell and T cells present 8 weeks following last N-803 treatment. CITE-seq revealed a therapy-altered NK cell molecular program, including enhancement of AP-1 transcription factor. Furthermore, the monocyte transcriptional program was remodeled with enhanced MHC expression and antigen-presentation genes. CONCLUSIONS: N-803 combines with mAbs to enhance tumor targeting in patients, and warrants further investigation in combination with immunotherapies.