First-in-human study of an EGFRvIII x CD3 T cell bispecific antibody in the treatment of newly diagnosed glioblastoma.

Background: This first-in-human study evaluated EGFRvIII × CD3 TCB, a novel T cell bispecific antibody, in patients with newly diagnosed EGFRvIII-positive glioblastoma.

Methods: Patients with newly diagnosed glioblastoma received escalating doses of EGFRvIII × CD3 TCB following chemoradiation. The primary objectives were to evaluate safety/tolerability and define the maximum tolerated dose (MTD); secondary objectives included pharmacokinetics (PK), immunogenicity, pharmacodynamics, and clinical activity.

IL-17A-secreting γδ T cells promote resistance to CDK4/CDK6 inhibitors in HRHER2 breast cancer via CX3CR1 macrophages.

Resistance to cyclin-dependent kinase 4/6 (CDK4/CDK6) inhibitors leads to treatment failure and disease progression in women with hormone receptorHER2 (HRHER2) breast cancer (BC). We delineated a hypoxia-sensitive, CCL2-dependent pathway recruiting interleukin-17A (IL-17A)-secreting γδ T cells to mouse HRHER2 BCs following CDK4/CDK6 inhibition, resulting in repolarization of tumor-associated macrophages (TAMs) toward an immunosuppressive CX3CR1 phenotype associated with resistance. Increased IL-17A signaling and intratumoral γδ T cell abundance positively correlated with advanced grade and/or reduced survival in two cohorts of individuals with HRHER2 BC.

Monocyte-lineage tumor infiltration predicts immunoradiotherapy response in advanced pretreated soft-tissue sarcoma: phase 2 trial results.

Immunoradiotherapy holds promise for improving outcomes in patients with advanced solid tumors, including in soft-tissue sarcoma (STS). However, the ideal combination of treatment modalities remains to be determined, and reliable biomarkers to predict which patients will benefit are lacking. Here, we report the results of the STS cohort of the SABR-PDL1 phase II trial that evaluated the anti-PDL1 atezolizumab combined with stereotactic body radiation therapy (SBRT) delivered concurrently with the 2nd cycle to at least one tumor site.

Safety and Antitumor Activity of a Novel aCD25 Treg Depleter RG6292 as a Single Agent and in Combination with Atezolizumab in Patients with Solid Tumors.

Purpose: Therapeutic depletion of immunosuppressive regulatory T cells (Treg) may overcome resistance to cancer immunotherapies. RG6292 is an anti-CD25 antibody that preferentially depletes Tregs while preserving effector T-cell functions in preclinical models. The safety, pharmacokinetics, pharmacodynamics, and antitumor efficacy of selective Treg depletion by RG6292 administered as monotherapy or in combination with atezolizumab were evaluated in two phase I studies.

4-1BB agonist targeted to fibroblast activation protein α synergizes with radiotherapy to treat murine breast tumor models.

Background: Ionizing radiation (IR) is a double-edged sword for immunotherapy as it may have both immunosuppressive and immunostimulatory effects. The biological effects of IR on the tumor microenvironment (TME) are a key factor for this balance. Fibroblast activation protein (FAP) is expressed on the surface of cancer-associated fibroblasts (CAF) in many cancer types and its abundance is associated with the poor immune response to immune-checkpoint-blockade in patients.

Cross-priming in cancer immunology and immunotherapy.

Cytotoxic T cell immune responses against cancer crucially depend on the ability of a subtype of professional antigen-presenting cells termed conventional type 1 dendritic cells (cDC1s) to cross-present antigens. Cross-presentation comprises redirection of exogenous antigens taken from other cells to the major histocompatibility complex class I antigen-presenting machinery. In addition, once activated and having sensed viral moieties or T helper cell cooperation via CD40-CD40L interactions, cDC1s provide key co-stimulatory ligands and cytokines to mount and sustain CD8 T cell immune responses.

NKG2C/ tumor cell expression enhances immunotherapeutic efficacy against glioblastoma.

Background: Activating and inhibitory receptors of natural killer (NK) cells such as NKp, NKG2, or CLEC are highly relevant to cold tumors including glioblastoma (GBM). Here, we aimed to characterize the expression of these receptors in GBM to gain insight into their potential role as modulators of the intratumoral microenvironment.

Methods: We performed a transcriptomic analysis of several NK receptors with a focus on the activating receptor encoded by NKG2C, among bulk and single-cell RNA sequencing GBM data sets.

CEA-CD3 bispecific antibody cibisatamab with or without atezolizumab in patients with CEA-positive solid tumours: results of two multi-institutional Phase 1 trials.

Cibisatamab is a bispecific antibody-based construct targeting carcinoembryonic antigen (CEA) on tumour cells and CD3 epsilon chain as a T-cell engager. Here we evaluated cibisatamab for advanced CEA-positive solid tumours in two open-label Phase 1 dose-escalation and -expansion studies: as a single agent with or without obinutuzumab in S1 (NCT02324257) and with atezolizumab in S2 (NCT02650713). Primary endpoints were safety, dose finding, and pharmacokinetics in S1; safety and dose finding in S2.

Safety, Pharmacokinetics, Pharmacodynamics, and Antitumor Activity from a Phase I Study of Simlukafusp Alfa (FAP-IL2v) in Advanced/Metastatic Solid Tumors.

Purpose: Simlukafusp alfa [fibroblast activation protein α-targeted IL2 variant (FAP-IL2v)], a tumor-targeted immunocytokine, comprising an IL2 variant moiety with abolished CD25 binding fused to human IgG1, is directed against fibroblast activation protein α. This phase I, open-label, multicenter, dose-escalation, and extension study (NCT02627274) evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of FAP-IL2v in patients with advanced/metastatic solid tumors.

Patients And Methods: Participants received FAP-IL2v intravenously once weekly.

Low-Dose Ionizing γ-Radiation Elicits the Extrusion of Neutrophil Extracellular Traps.

Purpose: Patients with cancer frequently undergo radiotherapy in their clinical management with unintended irradiation of blood vessels and copiously irrigated organs in which polymorphonuclear leukocytes circulate. Following the observation that such low doses of ionizing radiation are able to induce neutrophils to extrude neutrophil extracellular traps (NET), we have investigated the mechanisms, consequences, and occurrence of such phenomena in patients undergoing radiotherapy.

Experimental Design: NETosis was analyzed in cultures of neutrophils isolated from healthy donors, patients with cancer, and cancer-bearing mice under confocal microscopy.

Radiotherapy protocols for mouse cancer model.

Radiotherapy is a crucial treatment modality for cancer patients, with approximately 60% of individuals undergoing ionizing radiation as part of their disease management. In recent years, there has been a growing trend toward minimizing irradiation fields through the use of image-guided dosimetry and innovative technologies. These advancements allow for selective irradiation, delivering higher local doses while reducing the number of treatment sessions.

Cytotoxicity as a form of immunogenic cell death leading to efficient tumor antigen cross-priming.

Antigen cross-priming of CD8 T cells is a critical process necessary for the effective expansion and activation of CD8 T cells endowed with the ability to recognize and destroy tumor cells. The cross-presentation of tumor antigens to cross-prime CD8 T cells is mainly mediated, if not only, by a subset of professional antigen-presenting cells termed type-1 conventional dendritic cells (cDC1). The demise of malignant cells can be immunogenic if it occurs in the context of premortem stress.

Intratumoral neoadjuvant immunotherapy based on the BO-112 viral RNA mimetic.

BO-112 is a poly I:C-based viral mimetic that exerts anti-tumor efficacy when intratumorally delivered in mouse models. Intratumoral BO-112 synergizes in mice with systemic anti-PD-1 mAbs and this combination has attained efficacy in PD1-refractory melanoma patients. We sought to evaluate the anti-tumor efficacy of BO-112 pre-surgically applied in neoadjuvant settings to mouse models.

A simple method to assess clonogenic survival of irradiated cancer cells.

The clonogenic assay is an in vitro method based on the ability of a single cell to proliferate indefinitely into a colony. This assay is the gold standard method to analyze cell viability and quantify reproductive cell survival fraction after treatment with ionizing radiation and other cytotoxic agents in vitro. After the cytotoxic effect, only some cells retain their ability to grow from one cell and form colonies.

Flow cytometry-assisted quantification of immune cells infiltrating irradiated tumors in mice.

The immunomodulatory properties of local hypofractionated radiotherapy are known to promote the generation of anti-tumor immune responses. Such responses are largely due to the infiltration of cytotoxic lymphocytes (TILs) into the tumors that are able to destroy malignant lesions. In this context, characterizing the tumor immune microenvironment following radiotherapy is crucial for the study of its mechanism of action.

Intratumoral BO-112 in combination with radiotherapy synergizes to achieve CD8 T-cell-mediated local tumor control.

Background: Radioimmunotherapy combines irradiation of tumor lesions with immunotherapy to achieve local and abscopal control of cancer. Most immunotherapy agents are given systemically, but strategies for delivering immunotherapy locally are under clinical scrutiny to maximize efficacy and avoid toxicity. Local immunotherapy, by injecting various pathogen-associated molecular patterns, has shown efficacy both preclinically and clinically.

The Lymphatic Endothelium in the Context of Radioimmuno-Oncology.

The study of lymphatic tumor vasculature has been gaining interest in the context of cancer immunotherapy. These vessels constitute conduits for immune cells' transit toward the lymph nodes, and they endow tumors with routes to metastasize to the lymph nodes and, from them, toward distant sites. In addition, this vasculature participates in the modulation of the immune response directly through the interaction with tumor-infiltrating leukocytes and indirectly through the secretion of cytokines and chemokines that attract leukocytes and tumor cells.

Assessment of hypoxia by pimonidazole staining following radiotherapy.

The rapid proliferation of cancer cells and the aberrant vasculature present in most solid tumors frequently result in the lack of oxygen generating a hypoxic tumor microenvironment. Low levels of oxygen not only affect the tumor cell biology and tumorigenesis, but also the other components of the tumor microenvironment such as the tumor stroma and the immune infiltrate, promoting a more suppressive environment. In addition, tumor hypoxia has been associated with reduced sensitivity to chemotherapy (CH) and radiotherapy (RT), leading to poor outcomes in cancer patients.

Charting roadmaps towards novel and safe synergistic immunotherapy combinations.

Checkpoint inhibitor-based cancer immunotherapy is often combined in the clinic with other immunotherapy strategies, targeted therapies, chemotherapy or standard-of-care treatments to achieve superior therapeutic efficacy. The large number of immunotherapy combinations that are currently undergoing clinical testing necessitate the establishment of faithful criteria to prioritize optimal combinations with evidence of synergy, to determine their safety and optimal sequence of administration and to identify biomarkers of therapy resistance and response. In this review, we focus on recent developments in immunotherapy combinations and reflect on how combinations should be optimized to maximize the impact of immunotherapy in clinical oncology.

Soluble CD137 as a dynamic biomarker to monitor agonist CD137 immunotherapies.

Background: On the basis of efficacy in mouse tumor models, multiple CD137 (4-1BB) agonist agents are being preclinically and clinically developed. The costimulatory molecule CD137 is inducibly expressed as a transmembrane or as a soluble protein (sCD137). Moreover, the CD137 cytoplasmic signaling domain is a key part in approved chimeric antigen receptors (CARs).

Tumor ENPP1 (CD203a)/Haptoglobin Axis Exploits Myeloid-Derived Suppressor Cells to Promote Post-Radiotherapy Local Recurrence in Breast Cancer.

Abstract: Locoregional failure (LRF) in patients with breast cancer post-surgery and post-irradiation is linked to a dismal prognosis. In a refined new model, we identified ectonucleotide pyrophosphatase/phosphodiesterase 1/CD203a (ENPP1) to be closely associated with LRF. ENPP1hi circulating tumor cells (CTC) contribute to relapse by a self-seeding mechanism.

Preclinical Characterization and Phase I Trial Results of a Bispecific Antibody Targeting PD-L1 and 4-1BB (GEN1046) in Patients with Advanced Refractory Solid Tumors.

Unlabelled: Checkpoint inhibitors (CPI) have revolutionized the treatment paradigm for advanced solid tumors; however, there remains an opportunity to improve response rates and outcomes. In preclinical models, 4-1BB costimulation synergizes with CPIs targeting the programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) axis by activating cytotoxic T-cell-mediated antitumor immunity. DuoBody-PD-L1×4-1BB (GEN1046) is an investigational, first-in-class bispecific immunotherapy agent designed to act on both pathways by combining simultaneous and complementary PD-L1 blockade and conditional 4-1BB stimulation in one molecule.

Three-dimensional colon cancer organoids model the response to CEA-CD3 T-cell engagers.

The CEA-CD3 T cell bispecific antibody cibisatamab (CEA-TCB) is currently undergoing clinical trials. Here we study its performance against three-dimensional tumor organoids in cocultures with T cells as compared to a higher affinity CEACAM5-CD3 (CEACAM5-TCB) bispecific antibody using time-lapse confocal microscopy. Pre-labelled spheroids derived from colon cancer cell lines and primary organoids derived from four colorectal cancer surgical specimens, which expressed different graded levels of CEA, were exposed in cocultures to T lymphocytes.