Everolimus decreases [U-C]glucose utilization by pyruvate carboxylase in breast cancer cells in vitro and in vivo.

Reprogrammed metabolism is a hallmark of cancer, but notoriously difficult to target due to metabolic plasticity, especially in response to single metabolic interventions. Combining mTOR inhibitor everolimus and mitochondrial complex 1 inhibitor metformin results in metabolic synergy in in vitro models of triple-negative breast cancer. Here, we investigated whether the effect of this drug combination on tumor size is reflected in changes in tumor metabolism using [U-C]glucose labeling in an MDA-MB-231 triple negative breast cancer xenograft model.

Assessing the role of tumour-associated macrophage subsets in breast cancer subtypes using digital image analysis.

Purpose: The number of M1-like and M2-like tumour-associated macrophages (TAMs) and their ratio can play a role in breast cancer development and progression. Early clinical trials using macrophage targeting compounds are currently ongoing. However, the most optimal detection method of M1-like and M2-like macrophage subsets and their clinical relevance in breast cancer is still unclear.

Preclinical development of ZED8, an Zr immuno-PET reagent for monitoring tumor CD8 status in patients undergoing cancer immunotherapy.

Background: ZED8 is a novel monovalent antibody labeled with zirconium-89 for the molecular imaging of CD8. This work describes nonclinical studies performed in part to provide rationale for and to inform expectations in the early clinical development of ZED8, such as in the studies outlined in clinical trial registry NCT04029181 [1].

Methods: Surface plasmon resonance, X-ray crystallography, and flow cytometry were used to characterize the ZED8-CD8 binding interaction, its specificity, and its impact on T cell function.

Zr-3,2-HOPO-Mesothelin Antibody PET Imaging Reflects Tumor Uptake of Mesothelin-Targeted Th-Conjugate Therapy in Mice.

The mesothelin (MSLN)-targeted Th conjugate is a novel α-therapy developed to treat MSLN-overexpressing cancers. We radiolabeled the same antibody-chelator conjugate with Zr to evaluate whether PET imaging with Zr-MSLN matches Th-MSLN tumor uptake, biodistribution, and antitumor activity. Serial PET imaging with protein doses of 4, 20, or 40 μg of Zr-MSLN and Zr-control was performed up to 168 h after tracer injection in human tumor-bearing nude mice with high (HT29-MSLN) and low (BxPc3) MSLN expression.

Radiolabeled Monoclonal Antibody Against Colony-Stimulating Factor 1 Receptor Specifically Distributes to the Spleen and Liver in Immunocompetent Mice.

Macrophages can promote tumor development. Preclinically, targeting macrophages by colony-stimulating factor 1 (CSF1)/CSF1 receptor (CSF1R) monoclonal antibodies (mAbs) enhances conventional therapeutics in combination treatments. The physiological distribution and tumor uptake of CSF1R mAbs are unknown.

Preclinical PET imaging of bispecific antibody ERY974 targeting CD3 and glypican 3 reveals that tumor uptake correlates to T cell infiltrate.

Background: Bispecific antibodies redirecting T cells to the tumor obtain increasing interest as potential cancer immunotherapy. ERY974, a full-length bispecific antibody targeting CD3ε on T cells and glypican 3 (GPC3) on tumors, has been in clinical development However, information on the influence of T cells on biodistribution of bispecific antibodies, like ERY974, is scarce. Here, we report the biodistribution and tumor targeting of zirconium-89 (Zr) labeled ERY974 in mouse models using immuno-positron emission tomography (PET) imaging.

Zr-labeled Bispecific T-cell Engager AMG 211 PET Shows AMG 211 Accumulation in CD3-rich Tissues and Clear, Heterogeneous Tumor Uptake.

Purpose: Biodistribution of bispecific antibodies in patients is largely unknown. We therefore performed a feasibility study in 9 patients with advanced gastrointestinal adenocarcinomas to explore AMG 211 biodistribution (also known as MEDI-565), an approximately 55 kDa bispecific T-cell engager (BiTE®) directed against carcinoembryonic antigen (CEA) on tumor cells and cluster of differentiation 3 (CD3) on T-cells.

Experimental Design: Zr-labeled AMG 211 as tracer was administered alone or with cold AMG 211, for PET imaging before and/or during AMG 211 treatment.

Tumor-associated macrophages in breast cancer: Innocent bystander or important player?

Tumor-associated macrophages (TAMs) are important tumor-promoting cells in the breast tumor microenvironment. Preclinically TAMs stimulate breast tumor progression, including tumor cell growth, invasion and metastasis. TAMs also induce resistance to multiple types of treatment in breast cancer models.

Molecular Imaging of Radiolabeled Bispecific T-Cell Engager Zr-AMG211 Targeting CEA-Positive Tumors.

AMG 211, a bispecific T-cell engager (BiTE) antibody construct, targets carcinoembryonic antigen (CEA) and the CD3 epsilon subunit of the human T-cell receptor. AMG 211 was labeled with zirconium-89 (Zr) or fluorescent dye to evaluate the tumor-targeting properties. Zr-AMG211 was administered to mice bearing CEA-positive xenograft tumors of LS174T colorectal adenocarcinoma or BT474 breast cancer cells, as well as CEA-negative HL-60 promyelocytic leukemia xenografts.

Molecular Imaging in Cancer Drug Development.

Development of new oncology drugs has increased since the improved understanding of cancer's complex biology. The oncology field has become the top therapeutic research area for new drugs. However, only a limited number of drugs entering clinical trials will be approved for use as the standard of care for cancer patients.

Biodistribution and PET Imaging of Labeled Bispecific T Cell-Engaging Antibody Targeting EpCAM.

Unlabelled: AMG 110, a bispecific T cell engager (BiTE) antibody construct, induces T cell-mediated cancer cell death by cross-linking epithelial cell adhesion molecule (EpCAM) on tumor cells with a cluster of differentiation 3 ε (CD3ε) on T cells. We labeled AMG 110 with (89)Zr or near-infrared fluorescent dye (IRDye) 800CW to study its tumor targeting and tissue distribution.

Methods: Biodistribution and tumor uptake of (89)Zr-AMG 110 was studied up to 6 d after intravenous administration to nude BALB/c mice bearing high EpCAM-expressing HT-29 colorectal cancer xenografts.

Activation of AKT by hypoxia: a potential target for hypoxic tumors of the head and neck.

Background: Only a minority of cancer patients benefits from the combination of EGFR-inhibition and radiotherapy in head and neck squamous cell carcinoma (HNSCC). A potential resistance mechanism is activation of EGFR and/or downstream pathways by stimuli in the microenvironment. The aim of this study was to find molecular targets induced by the microenvironment by determining the in vitro and in vivo expression of proteins of the EGFR-signaling network in 6 HNSCC lines.