First Data for ImmunityBio’s Memory Cytokine-Enriched NK Cells in Small Cell Lung Cancer at SITC Meeting Show Promising Anti-tumor Activity

ImmunityBio, Inc. (NASDAQ: IBRX), a clinical-stage immunotherapy company, today announced new data showing that the company’s Memory Cytokine-Enriched Natural Killer cells (M-ceNK) may provide benefit to patients with small cell lung cancer and patients with other types of neuroendocrine tumors. Findings from the study titled “Characterization of the anti-tumor activity of memory cytokine enriched NK cells (M-ceNK) against tumors with neuroendocrine features” were presented by Kristen Fousek, Ph.D., Research Fellow with the Center for Immuno-Oncology of the National Institutes of Health’s National Cancer Institute (NCI) in a poster session (Abstract #358) at the annual meeting of the Society for Immunotherapy of Cancer (SITC) in San Diego, November 4, 2023.

Small cell lung cancer (SCLC) is an aggressive neuroendocrine (NE) carcinoma and has few treatment options. Although immune checkpoint blockade (ICB) is approved in combination with chemotherapy in extensive stage disease, only a subset of patients experience an improvement in overall survival. Studies suggest that a lack of response to ICB is partially attributable to low expression of MHC-class I. Recently, an NCI research group (Fousek et al., 2023) reported that the lack of MHC-class I can be leveraged to enable targeting by NK cells stimulated with ImmunityBio’s IL-15 cytokine superagonist N-803. These findings led researchers to hypothesize that M-ceNK cells may be effective in targeting SCLC.

In the new study, the killing capacity of M-ceNK cells was assessed in four SCLC cell lines representing the major molecular subtypes. M-ceNK cells, generated from cells from several healthy donors, were found to express high levels of activating receptors and low levels of inhibitory receptors, as well as elevated IFN-γ and granzyme B production – all of which are important for anti-tumor activity. The M-ceNK cells were highly cytotoxic against all types of SCLC models, as well as against prostate neuroendocrine cancer. Overall, the study revealed the potential for M-ceNK-based approaches for the treatment of NE tumors, including all molecular subtypes of SCLC and supports future studies in other tumor types that are unresponsive to ICB.