Treatment of non-small cell lung cancer (NSCLC) has drastically changed in recent years owing to the robust anticancer effects of immune checkpoint inhibitors (ICI). However, only 20% of the patients with NSCLC benefit from ICIs, highlighting the need to uncover the mechanisms mediating resistance. By analyzing the overall survival (OS) and mutational profiles of 424 patients with NSCLC who received ICI treatments between 2015 and 2021, we determined that patients carrying a loss-of-function mutation in neurotrophic tyrosine kinase receptor 1 (NTRK1) had a prolonged OS when compared with patients with wild-type NTRK1. Notably, suppression of the NTRK1 pathway by knockdown or entrectinib treatment significantly enhanced ICI efficacy in mouse NSCLC models. Comprehensive T-cell population analyses demonstrated that stem-like CD4+ T cells and effector CD4+ and CD8+ T cells were highly enriched in anti-PD-1-treated mice bearing tumors with decreased NTRK1 signaling. RNA sequencing revealed that suppression of NTRK1 signaling in tumor cells increased complement C3 expression, which enhanced the recruitment of T cells and myeloid cells and stimulated M1-like macrophage polarization in the tumor. Together, this study demonstrates a role for NTRK1 signaling in regulating cross-talk between tumor cells and immune cells in the tumor microenvironment and provides a potential therapeutic approach to overcome immunotherapy resistance in patients with NSCLC with NTRK1 wild-type. Significance: Inhibition of NTRK1 signaling confers sensitivity to immunotherapy by enhancing complement C3-mediated T-cell and macrophage functions, leading to improved responses to immune checkpoint inhibitors in patients with lung cancer with NTRK1 mutations.
©2024 American Association for Cancer Research.

Memory T cells demonstrate superior in vivo persistence and antitumor efficacy. However, methods for manufacturing less differentiated T cells are not yet well-established. Here, we show that producing chimeric antigen receptor (CAR)-T cells using berbamine (BBM), a natural compound found in the Chinese herbal medicine Berberis amurensis, enhances the antitumor efficacy of CAR-T cells. BBM is identified through cell-based screening of chemical compounds using induced pluripotent stem cell-derived T cells, leading to improved viability with a memory T cell phenotype. Transcriptomics and metabolomics using stem cell memory T cells reveal that BBM broadly enhances lipid metabolism. Furthermore, the addition of BBM downregulates the phosphorylation of p38 mitogen-activated protein kinase and enhanced mitochondrial respiration. CD19-CAR-T cells cultured with BBM also extend the survival of leukaemia mouse models due to their superior in vivo persistence. This technology offers a straightforward approach to enhancing the antitumor efficacy of CAR-T cells.
© 2024. The Author(s).

Receptor occupancy (RO) assessment by flow cytometry is an important pharmacodynamic (PD) biomarker in the clinical development of large molecules such as monoclonal therapeutic antibodies (mAbs). The total-drug-bound RO assay format directly assesses mAb binding to cell surface targets using anti-drug detection antibodies. Here, we generated a flow cytometry detection antibody specifically binding to mAbs of the IgG1 P329GLALA backbone. Using this reagent, we developed a total-drug-bound RO assay format for RG7769, a bi-specific P329GLALA containing mAb targeting PD-1 and TIM3 on T cells. In its fit-for-purpose validated version, this RO assay has been used in the Phase-I dose escalation study of RG7769, informing on peripheral T cell RO and RG7769 antibody binding capacity (ABC). We assessed RG7769 RO in checkpoint-inhibitor (CPI) naïve patients and anti-PD-1 CPI experienced patients using our novel assay. Here, we show that in both groups, complete T cell RO can be achieved (~100%). However, we found that the maximum number of T cell binding sites for RG7769 pre-dosing was roughly twofold lower in patients recently having undergone anti-PD-1 treatment. We show that this is due to steric hindrance exerted by competing mAbs masking the available drug binding sites. Our findings highlight the importance of quantitative mAb assessment in addition to relative RO especially in the context of patients who have previously received anti-PD-1 treatment.
© 2021 The Authors. Cytometry Part A published by Wiley Periodicals LLC on behalf of International Society for Advancement of Cytometry.

Immune checkpoint inhibitors demonstrate clinical activity in many tumor types, however, only a fraction of patients benefit. Combining CD137 agonists with these inhibitors increases anti-tumor activity preclinically, but attempts to translate these observations to the clinic have been hampered by systemic toxicity. Here we describe a human CD137xPD-L1 bispecific antibody, MCLA-145, identified through functional screening of agonist- and immune checkpoint inhibitor arm combinations. MCLA-145 potently activates T cells at sub-nanomolar concentrations, even under suppressive conditions, and enhances T cell priming, differentiation and memory recall responses. In vivo, MCLA-145 anti-tumor activity is superior to immune checkpoint inhibitor comparators and linked to recruitment and intra-tumor expansion of CD8 + T cells. No graft-versus-host-disease is observed in contrast to other antibodies inhibiting the PD-1 and PD-L1 pathway. Non-human primates treated with 100 mg/kg/week of MCLA-145 show no adverse effects. The conditional activation of CD137 signaling by MCLA-145, triggered by neighboring cells expressing >5000 copies of PD-L1, may provide both safety and potency advantages.
© 2021. The Author(s).

Autologous chimeric antigen receptor engineered T-cell therapies are beginning to dramatically change the outlook for patients with several hematological malignancies. Yet methods to activate and expand these cells are limited, often pose challenges to automation, and have biological limitations impacting the output of the injectable dose. This study describes the development of a novel, highly flexible, soluble DNA-based T-cell activation and expansion platform which alleviates the limitations of current technologies and provides rapid T-cell activation and expansion.