Memory Cytokine-Enhanced Natural Killer Cells Show Promising Results in Leukemia Patients; Data Support ImmunityBio’s Scaled m-ceNK Clinical Program

ImmunityBio, Inc. (NASDAQ: IBRX), a clinical-stage immunotherapy company, today announced study results that further demonstrate the potential for use of memory-like cytokine-enriched natural killer (m-ceNK) cells for the treatment of cancer. ImmunityBio has successfully scaled the process of generating over 20 billion m-ceNK cells from a single extraction of white blood cells from a donor or patient, and reports promising clinical data supporting the ongoing development of memory NK cells for the treatment of both liquid and solid tumors of all types.

In a Phase 2 study sponsored by Washington University School of Medicine (NCT02782546), white blood cells retrieved from HCT donors to treat acute myeloid leukemia (AML) patients, were stimulated with cytokines (IL-12, -15, and -18) to form memory-like NK cells, and were re-infused to the patients, who also received ImmunityBio’s IL-15 superagonist Anktiva (N-803). The cytokine-stimulated NK cells safely augmented a leading treatment for AML-—HLA-haploidentical hematopoietic cell transplantation. The data showed that the cytokine-stimulated NK cells were persistent, showed increased production of interferon-gamma and functionality, and led to a complete response in 87% of patients after Day 28. The results were recently published in a peer-reviewed article (“Hematopoietic cell transplantation donor-derived memory-like NK cells functionally persist after transfer into patients with leukemia”) in Science Translational Medicine.

NK cells are innate immune cells that are under investigation as a cell therapy for multiple types of cancer. A challenge of NK cell-based therapies, however, is ensuring that the cells persist and remain functional long-term. This study showed that memory-like NK cells derived from the same donor as the hematopoietic cell transplantation (HCT) persisted for at least two months after transplantation and were highly functional ex vivo. Together, these findings support the use of memory NK cells as a component of HCT for leukemia.

“This important study adds to the growing body of data that shows the cancer-fighting ability of NK cells can be enhanced by stimulating expansion and persistence of these cells,” said Patrick Soon-Shiong, M.D., Executive Chairman and Global Chief Scientific and Medical Officer at ImmunityBio. “The study also showed that stimulated memory NK cells are effective with only a single infusion when given along with Anktiva support. To facilitate this approach, ImmunityBio has successfully scaled cytokine enrichment and expansion of m-ceNK cells, so cancer patients can receive multiple infusions of these potent and persistent m-ceNK cells generated from a single donation of white blood cells.”