Safety Profiling of Tumor-targeted T Cell-Bispecific Antibodies with Alveolus Lung- and Colon-on-Chip.

Traditional drug safety assessments often fail to predict complications in humans, especially when the drug targets the immune system. Rodent-based preclinical animal models are often ill-suited for predicting immunotherapy-mediated adverse events in humans, in part because of the fundamental differences in immunological responses between species and the human relevant expression profile of the target antigen, if it is expected to be present in normal, healthy tissue. While human-relevant cell-based models of tissues and organs promise to bridge this gap, conventional in vitro two-dimensional models fail to provide the complexity required to model the biological mechanisms of immunotherapeutic effects. Also, like animal models, they fail to recapitulate physiologically relevant levels and patterns of organ-specific proteins, crucial for capturing pharmacology and safety liabilities. Organ-on-Chip models aim to overcome these limitations by combining micro-engineering with cultured primary human cells to recreate the complex multifactorial microenvironment and functions of native tissues and organs. In this protocol, we show the unprecedented capability of two human Organs-on-Chip models to evaluate the safety profile of T cell-bispecific antibodies (TCBs) targeting tumor antigens. These novel tools broaden the research options available for a mechanistic understanding of engineered therapeutic antibodies and for assessing safety in tissues susceptible to adverse events. Graphical abstract Figure 1. Graphical representation of the major steps in target-dependent T cell-bispecific antibodies engagement and immunomodulation, as performed in the Colon Intestine-Chip.

Performance assessment and economic analysis of a human Liver-Chip for predictive toxicology.

BACKGROUND: Conventional preclinical models often miss drug toxicities, meaning the harm these drugs pose to humans is only realized in clinical trials or when they make it to market. This has caused the pharmaceutical industry to waste considerable time and resources developing drugs destined to fail. Organ-on-a-Chip technology has the potential improve success in drug development pipelines, as it can recapitulate organ-level pathophysiology and clinical responses; however, systematic and quantitative evaluations of Organ-Chips' predictive value have not yet been reported. METHODS: 870 Liver-Chips were analyzed to determine their ability to predict drug-induced liver injury caused by small molecules identified as benchmarks by the Innovation and Quality consortium, who has published guidelines defining criteria for qualifying preclinical models. An economic analysis was also performed to measure the value Liver-Chips could offer if they were broadly adopted in supporting toxicity-related decisions as part of preclinical development workflows. RESULTS: Here, we show that the Liver-Chip met the qualification guidelines across a blinded set of 27 known hepatotoxic and non-toxic drugs with a sensitivity of 87% and a specificity of 100%. We also show that this level of performance could generate over $3 billion annually for the pharmaceutical industry through increased small-molecule R&D productivity. CONCLUSIONS: The results of this study show how incorporating predictive Organ-Chips into drug development workflows could substantially improve drug discovery and development, allowing manufacturers to bring safer, more effective medicines to market in less time and at lower costs.

Drug development is lengthy and costly, as it relies on laboratory models that fail to predict human reactions to potential drugs. Because of this, toxic drugs sometimes go on to harm humans when they reach clinical trials or once they are in the marketplace. Organ-on-a-Chip technology involves growing cells on small devices to mimic organs of the body, such as the liver. Organ-Chips could potentially help identify toxicities earlier, but there is limited research into how well they predict these effects compared to conventional models. In this study, we analyzed 870 Liver-Chips to determine how well they predict drug-induced liver injury, a common cause of drug failure, and found that Liver-Chips outperformed conventional models. These results suggest that widespread acceptance of Organ-Chips could decrease drug attrition, help minimize harm to patients, and generate billions in revenue for the pharmaceutical industry.

Human immunocompetent Organ-on-Chip platforms allow safety profiling of tumor-targeted T-cell bispecific antibodies.

Traditional drug safety assessment often fails to predict complications in humans, especially when the drug targets the immune system. Here, we show the unprecedented capability of two human Organs-on-Chips to evaluate the safety profile of T-cell bispecific antibodies (TCBs) targeting tumor antigens. Although promising for cancer immunotherapy, TCBs are associated with an on-target, off-tumor risk due to low levels of expression of tumor antigens in healthy tissues. We leveraged in vivo target expression and toxicity data of TCBs targeting folate receptor 1 (FOLR1) or carcinoembryonic antigen (CEA) to design and validate human immunocompetent Organs-on-Chips safety platforms. We discovered that the Lung-Chip and Intestine-Chip could reproduce and predict target-dependent TCB safety liabilities, based on sensitivity to key determinants thereof, such as target expression and antibody affinity. These novel tools broaden the research options available for mechanistic understandings of engineered therapeutic antibodies and assessing safety in tissues susceptible to adverse events.

Toward Automated Additive Manufacturing of Living Bio-Tubes Using Ring-Shaped Building Units.

Tissue engineering has been largely confined to academic research institutions with limited success in commercial settings. To help address this issue, more work is needed to develop new automated manufacturing processes for tissue-related technologies. In this article, we describe the automation of the funnel-guide, an additive manufacturing method that uses living tissue rings as building units to form bio-tubes. We developed a method based on 96-well plates and a modified off-the-shelf liquid-handling robot to retrieve, perform real-time quality control, and transfer tissue rings to the funnel-guide. Cells seeded into 96-well plates containing specially designed agarose micromolds self-assembled and formed ring-shaped microtissues that could be retrieved using a liquid-handling robot. We characterized the effects of time, cell type, and mold geometry on the morphology of the ring-shaped microtissues to inform optimal use of the building parts. We programmed and modified an off-the-shelf liquid-handling robot to retrieve ring-shaped microtissues from the 96-well plates, and we fabricated a custom illuminated pipette to visualize each ring-shaped microtissue prior to deposit in the funnel guide. Imaging at the liquid-air interface presented challenges that were overcome by controlling lighting conditions and liquid curvature. Based on these images, we incorporated into our workflow a real-time quality control step based on visual inspection and morphological criteria to assess each ring prior to use. We used this system to fabricate bio-tubes of endothelial cells with luminal alignment.

Design of a Fibrin Microthread-Based Composite Layer for Use in a Cardiac Patch.

The ability to modulate the mechanical properties, and cell alignment within a cardiac patch without hindering cell functionality may have significant impact on developing therapies for treating myocardial infarctions. We developed fibrin-based composite layers comprising aligned microthreads distributed uniformly throughout a hydrogel. Increasing the microthread volume fraction (∼5%, 11% and 22%) significantly increased the moduli of the scaffolds (20.6 ± 8.1, 46.4 ± 23.0, and 97.5 ± 49.3 kPa, respectively), p < 0.05. Analyses of cell-mediated contractile strains and frequencies showed no significant differences among composite layers and fibrin hydrogel controls, suggesting that microthread-based composite layers exhibit similar active functional properties. Cell orientation in composite layers suggests an increase in nuclear alignment within 100 µm of fibrin microthreads and suggests that microthreads influence the alignment in adjacent areas. In this study, we developed composite layers with tunable, mechanical patch properties that improve cell alignment and support cell functionality.