Lauren Dong, Hyejin Choi, Sadna Budhu, Isabell Schulze, Svena Verma, Levi M Mangarin, Valeria Estrada Nevarro, Nezar Mehanna, Jonathan F Khan, Divya Venkatesh, Daniel Thach, Neal Rosen, Jedd D Wolchok, Taha Merghoub
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引用次数: 0
Abstract
MEK inhibitors (MEKi) have shown limited success as a treatment for MAPK/ERK pathway-dependent cancers due to various resistance mechanisms tumor cells can employ. CH5126766 (CKI27) is an inhibitor that binds to MEK and prevents release of RAF, reducing the relief of negative feedback commonly observed with other MEKis. We observed that CKI27 increased MHC expression in tumor cells and improved T cell-mediated killing. Yet, CKI27 also decreased T-cell proliferation, activation, and cytolytic activity by inhibiting the MAPK/ERK pathway that is activated downstream of T-cell receptor signaling. Therefore, we aimed to balance the positive and negative immunomodulatory effects of MEKis for optimal combination with immunotherapy. Intermittent administration of CKI27 allowed T cells to partially recover and costimulation via GITR and OX-40 agonist antibodies completely alleviated inhibition of function. In Kras mutant lung and colon tumor mouse models, intermittent CKI27 and anti-GITR significantly decreased tumor growth and prolonged survival when further combined with CTLA-4 immune checkpoint blockade. Moreover, this triple combination increased CD8+ and CD4+ T-cell proliferation, activation, and effector/memory subsets in the tumor-draining lymph nodes and tumors and led to intratumoral regulatory T-cell destabilization. These data, collectively, will allow for more informed decisions when optimizing combination regimens by overcoming resistance, reducing toxicity, and generating long-term immune responses.
期刊介绍:
Cancer Immunology Research publishes exceptional original articles showcasing significant breakthroughs across the spectrum of cancer immunology. From fundamental inquiries into host-tumor interactions to developmental therapeutics, early translational studies, and comprehensive analyses of late-stage clinical trials, the journal provides a comprehensive view of the discipline. In addition to original research, the journal features reviews and opinion pieces of broad significance, fostering cross-disciplinary collaboration within the cancer research community. Serving as a premier resource for immunology knowledge in cancer research, the journal drives deeper insights into the host-tumor relationship, potent cancer treatments, and enhanced clinical outcomes.
Key areas of interest include endogenous antitumor immunity, tumor-promoting inflammation, cancer antigens, vaccines, antibodies, cellular therapy, cytokines, immune regulation, immune suppression, immunomodulatory effects of cancer treatment, emerging technologies, and insightful clinical investigations with immunological implications.