IL-18–secreting CAR T cells targeting DLL3 are highly effective in small cell lung cancer models
Janneke E. Jaspers, … , Charles M. Rudin, Renier J. Brentjens
Janneke E. Jaspers, … , Charles M. Rudin, Renier J. Brentjens
Published March 23, 2023
Citation Information: J Clin Invest. 2023;133(9):e166028. https://doi.org/10.1172/JCI166028.
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Research Article Immunology Oncology

IL-18–secreting CAR T cells targeting DLL3 are highly effective in small cell lung cancer models

Abstract

Patients with small cell lung cancer (SCLC) generally have a poor prognosis and a median overall survival of only about 13 months, indicating the urgent need for novel therapies. Delta-like protein 3 (DLL3) has been identified as a tumor-specific cell surface marker on neuroendocrine cancers, including SCLC. In this study, we developed a chimeric antigen receptor (CAR) against DLL3 that displays antitumor efficacy in xenograft and murine SCLC models. CAR T cell expression of the proinflammatory cytokine IL-18 greatly enhanced the potency of DLL3-targeting CAR T cell therapy. In a murine metastatic SCLC model, IL-18 production increased the activation of both CAR T cells and endogenous tumor-infiltrating lymphocytes. We also observed an increased infiltration, repolarization, and activation of antigen-presenting cells. Additionally, human IL-18–secreting anti-DLL3 CAR T cells showed an increased memory phenotype, less exhaustion, and induced durable responses in multiple SCLC models, an effect that could be further enhanced with anti–PD-1 blockade. All together, these results define DLL3-targeting CAR T cells that produce IL-18 as a potentially promising novel strategy against DLL3-expressing solid tumors.

Authors

Janneke E. Jaspers, Jonathan F. Khan, William D. Godfrey, Andrea V. Lopez, Metamia Ciampricotti, Charles M. Rudin, Renier J. Brentjens

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Figure 2

CAR T cell–secreted IL-12 and, especially, IL-18 prolong survival in murine SCLC model.

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CAR T cell–secreted IL-12 and, especially, IL-18 prolong survival in mur...
(A) Luciferase killing assay with murine CAR T cells and mSCLC cells that endogenously express murine DLL3 (n = 3). The CAR consists of the SC16.8 single-chain variable fragment (scFv) and murine CD28 and CD3ζ domains. (B) IFN-γ levels in supernatant of 24-hour coculture of murine CAR T cells with or without mSCLC cells. **P < 0.01, ****P < 0.0001 (2-way ANOVA, n = 2). (C) Survival of mice with metastatic mSCLC that were treated with the indicated doses of SC16.8m28mz CAR T cells (day 7) with or without 50 mg/kg cyclophosphamide pretreatment (day 6). **P < 0.01 (log-rank test, n = 4–6). (D) Schematic of CAR design with SC16.8 scFv, murine CD28 and CD3ζ signaling domains, and the murine Il12 fusion transgene or murine Il18 transgene. IRES, internal ribosome entry site. (E) IFN-γ production by the respective CAR T cells in the absence and presence of mSCLC cells. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 (2-way ANOVA and Student’s t test, n = 2–3). (F) Luciferase killing assay with SC16.8 CAR T cells that express IL-12, IL-18, or no cytokine and 4H11 CAR T cells as negative control (n = 3). (G and H) Serum IFN-γ and TNF-α levels (n = 12–15) and circulating CAR T cells (n = 5) in the blood of mice collected 3 days after treatment with the indicated CAR T cells. **P < 0.01, ***P < 0.001, ****P < 0.0001 (1-way ANOVA). (I) Tumor growth in mice that were treated with 2 × 106 CAR T cells intravenously 7 days after systemic mSCLC administration (n = 12–15). (J) Survival of mice in I. *P < 0.05, ****P < 0.0001 (log-rank test). (K) DLL3 surface expression on end-stage tumors from mice treated with SC16.8m28mz_mIL12 (red) or SC16.8m28mz_mIL18 (blue) CAR T cells.