New Model Will Support Drug Discovery for Liver Disease NASH

Non-alcoholic steatohepatitis (NASH) is a form of non-alcoholic fatty liver disease (NAFLD) which can lead to fibrosis of the liver, cirrhosis and, in some cases, liver cancer. Currently, there are no approved therapeutics to treat NASH, and worryingly the prevalence of the disease has increased significantly in recent years.

To drive forward drug discovery for NASH, better disease models are needed to overcome the limitations associated with the use of 2D culture and animal models. A new kit – PhysioMimix™ NASH “in-a-box” – launched today by CN Bio aims to address this issue and provide scientists with access to a human-relevant model that recreates the human liver environment more closely.

To learn more about NASH “in-a-box” and how it can help to advance drug discovery for NASH, Technology Networks spoke to Dr. Audrey Dubourg, product manager at CN Bio. In this interview, Dubourg also discusses some of the factors that scientists looking to adopt organ-on-a-chip (OOC) technology should consider.

Anna MacDonald (AM): There are currently limited treatment options available for NASH patients. Can you explain some of the reasons for this?

Audrey Dubourg (AD): NASH is the most severe form of NAFLD, a common liver disorder that affects 25% of our global population. NASH encompasses a wide spectrum of metabolic diseases in which fat builds up in the liver, mainly due to diet and lifestyle, in the absence of excess alcohol consumption, and leads to steatosis, inflammation, fibrosis and insulin resistance. Due to its complexity and its multifactorial root cause, it is challenging to develop one treatment that will work for all NASH patients. Moreover, most treatment options do not make it to the market because of unsuspected safety issues only identified in clinical trials or a lack of efficacy when testing the compounds in patients. Despite the growing prevalence of this metabolic disorder and much R&D effort, there are currently no regulatory approved NASH therapeutics and as a result, NASH is poised to become a huge economic burden.

Drug failures are mostly due to the inability of current preclinical in vitro and in vivo models to accurately recapitulate the human NASH phenotype and, as a consequence, their ability to reliably predict human outcomes. Despite there being a wide variety of pre-clinical NASH models available, predicting the efficacy of developmental drugs in humans remains a challenge. Most in vitro approaches use 2D monolayer, or spheroid models which are not representative of the human liver. Whilst in vivo models offer a clear “systems” advantage over current in vitro approaches, cross-species differences remain a valid data translatability concern, and unfortunately, no one model can recreate the many phenotypes of human NASH – as discussed in more detail in this blog: Of Mice and Men – Will human organ-on-a-chip disease models replace animal use?

Through the complementary use of human-relevant OOC assays, our aim is to help customers to improve the accuracy and efficiency of drug discovery. By generating high-content and clinically translatable data, that researchers use to unlock disease mechanisms, confirm drug safety and efficacy earlier in the drug development workflow, the ultimate end-goal of OOC is to prevent costly failures in the clinic and end the curse that has so far thwarted all NASH therapeutic discovery efforts.

AM: Can you tell us more about CN Bio’s PhysioMimix NASH “in-a-box” kit?

AD: Most disruptive technologies come with a plethora of hurdles that hinder their rapid adoption. The PhysioMimix “in-a-box” range is designed to circumvent these, fast-tracking the incorporation of human-relevant OOC technology into drug discovery workflows so that the benefits can be realized more quickly.

Our unique PhysioMimix NASH-in-a-box kit contains everything required by a customer to quickly and easily recreate our proprietary, industry-proven in vitro NASH model in their own laboratory; including primary cells validated to grow in 3D, bespoke NASH media and supplements, PhysioMimix Liver-on-a-Chip multi-well plates, plus quality control assay kits (LDH and Albumin) that confirm cell health during culture. To ensure the highest level of human-relevance, these kits are solely compatible with the PhysioMimix OOC range of microphysiological systems.

To support users of any experience, our software-based protocol module guides users step-by-step through the process of co-culturing primary human hepatocytes, stellate and Kupffer cells to form 3D microtissue structures that accurately emulate the human liver and its microarchitecture. By challenging the model with fatty acids, the disease state is induced which recapitulates key NASH stages: intracellular fat accumulation, inflammation and fibrosis. Once created, the model enables the precise mechanistic effects of drugs (of any modality) and disease to be teased out via high content, clinically translatable end-point measurements.

AM: How can the range of “in-a-box” kits help to advance drug discovery for conditions such as NASH? What benefits do the kits offer researchers?

AD: To advance drug discovery, NASH-in-a-box provides access to CN Bio’s proprietary Liver-on-a-chip technology, found by the US FDA to offer a superior performance versus traditional in vitro approaches (Rubiano A. et al., 2021). From this foundation, our best-in-class NASH disease model was developed and validated through collaboration with industry (Kostrzewski T. et al., 2021) and academic experts (Vacca M et al., 2020) over the last five years.

Previously, the only way to access this advanced human in vitro NASH model was via the Services arm of our business. Now the NASH-in-a-box kit, (used in conjunction with a PhysioMimix OOC Single-or Multi-Organ System), enables users to bring this capability in-house. Customers can now derive human-relevant insights into disease mechanism, drug efficacy and safety toxicology from the convenience of their own laboratory. 

Researchers using the kit benefit from a decade of CN Bio’s R&D experience saving them significant time, money and resource in terms of assay development. Along the way, we have learnt that the key to a successful assay stretches far beyond just the protocol and therefore we leave nothing to chance with respect to our kit components and our approach.

Sourcing high quality primary cells, for example, does not guarantee assay success because of donor to donor and lot to lot variation in performance. The most important part of any successful in vitro OOC model is assessing how well primary cells mimic their human counterpart when co-cultured together. As you can imagine, this is a costly and time-consuming task! To ensure that any user, irrespective of experience, can generate reliable and clinically translatable data from our kits, we provide pre-qualified and validated primary cells and their cell culture media.

Getting started with OOC assays could be daunting for those who have never cultured cells, or cultured cells in 3D before, so we have designed a software-based protocol module that guides users through the process in a step-by-step manner. Quality control assays are also included so that users feel confident that data they generate from NASH-in-a-box assays can be used to inform decisions about which NASH therapeutics to put forward to the clinic.

AM: What factors should scientists looking to adopt OOC technology consider?

AD: They are many factors to consider when evaluating which OOC technology to adopt. OOC solutions come in different shapes and flavors, each bringing different benefits, as well as limitations. The most important factor to consider is – does this technology meet my research needs? For example, is throughput and automation compatibility more important than physiological relevance and high content endpoint measurements, or vice versa? Where high human relevance is required, fluidic flow is an essential feature. Fluidic flow mimics the blood stream, providing nutrients, removing waste and delivering human-relevant sheer forces, all of which are essential for maintaining culture longevity, accurately recapitulating human organ pathophysiology and function.

Flexibility is an important consideration. Do you prefer a prescriptive, one-size fits all approach, or would you like the freedom to fine-tune/adapt models to match human counterparts as closely as possible, in which case an open architecture system is preferable.

Finally, to future proof an investment, the ability to run single-, and multi-organ models should be considered. New, interconnected multi-organ (gut and liver) models recreate human processes in the laboratory, such as first-pass metabolism to estimate drug bioavailability, a parameter that is predominantly derived using animal models that poorly predict human outcomes. A more detailed discussion can be found in a recent blog, Debunking the 9 myths of organ-on-a-chip technology.

AM: What further steps need to be taken before OOC technology becomes more widely integrated into the drug development pipeline by pharmaceutical companies?

AD: The main challenge faced is regulatory acceptance. Very few investigational new drug (IND) submissions currently use OOC data to support clinical development, with regulators still expecting studies to provide animal model data. Although this is slowly changing as OOC technology becomes more widely known, regulators remain conservative. Following on from this, there is the issue of standardization. Without all OOC technology and models working to the same reference standards, this remains a hurdle to adoption and therefore a key focus for us.

A key aspect of our approach is to closely collaborate with stakeholders in academia, pharma and biotech, plus regulators, such as the FDA, to expand the body of evidence that demonstrates the utility and reliance of OOC. Alongside this, we work with consortiums, such as the IQ-MPS Affiliative who assess new technologies and standardize endpoint assays to help fast-track the widespread adoption of OOC and kits, such as ours, into drug development workflows and hopefully IND submissions in the not-too-distant future.

Dr. Audrey Dubourg was speaking to Anna MacDonald, Science Writer for Technology Networks.