Experimental Design Considerations for MASH Drug Screening

An ongoing challenge in MASH drug screening and discovery, formerly known as NASH drug discovery, is selecting “fit-for-purpose” models for preclinical drug screening. InSphero liver expert Sue Grepper and Head of Liver Solutions Eva Thoma recently wrote a GEN Tutorial on this topic to help MASH researchers choose the right experimental design considerations for MASH/NASH drug screening while testing for promising lead candidates and combination therapies before advancing to clinical trials.

Here's what they recommend.

What makes a MASH/NASH model clinically relevant for drug testing?

A clinically relevant MASH/NASH model should reflect the biological features that matter for the drug development question being asked. These may include steatosis, inflammation, fibrosis-related mechanisms, metabolic dysfunction, long-term treatment compatibility, and measurable endpoints that can support candidate selection or mechanistic interpretation.

No single model can fully reproduce the complete progression of human MASH. The right model should therefore be selected based on the study objective: early compound screening, mechanism-of-action work, combination testing, fibrosis-related biology, or translational decision support.

Choosing the right model system for MASH drug screening and discovery

Preclinical model systems are invaluable tools for drug discovery and development. But many complex diseases, such as metabolic dysfunction-associated steatohepatitis, or MASH, remain difficult to recapitulate in the laboratory. Previously known as nonalcoholic steatohepatitis, or NASH, MASH is a progressive metabolic disease that takes years, if not decades, to develop in humans.

Successfully modeling all the key physiological events (from steatosis to inflammation and fibrosis) evident in clinical MASH has been extremely challenging in both in vivo animal models and in vitro cell-based models.

Conventional in vitro models, such as human hepatocytes cultured in 2D, offer a fast, efficient means to assess certain characteristics of MASH with compound testing (for example, the compound’s EC₅₀), but they lack other cell types involved in the disease’s progression and are often suitable only for short-term assays.

More advanced tissue-specific, human 3D co-culture systems, such as InSphero’s 3D InSight™ Human Liver Microtissues, are more appropriate for evaluating compound mechanisms of action in long-term experiments, but they, too, are limited in their ability to mimic NASH progression.

So...how do you choose the most suitable model at each stage of MASH drug development?

How to choose between MASH models for drug development

Model selection should start with the decision the study needs to support. Mouse models may be useful for systemic disease biology, while human in vitro models can provide controlled, scalable, and human-relevant data for compound screening and mechanistic studies.

For early drug discovery, researchers should consider whether the model supports relevant disease features, reproducible endpoints, sufficient treatment duration, and practical throughput. The best model is not necessarily the most complex one, but the one that produces decision-enabling data for the specific stage of development.

A checklist for data-driven experimental design in MASH drug discovery

One of the first things we do when we meet with a new MASH discovery partner with a promising lead candidate or a long list of potential combination therapies is to develop a detailed experimental program.

Together, we discuss what type of information is needed to answer the pathophysiological and mechanistic questions at hand. We can then make informed decisions about which models, assays, and endpoints are best suited to answer those questions.

We've found that it often helps to organize this information into a simple checklist that we can use as we map out a strategy for rigorously testing monotherapies and combination therapies in vitro.

Which endpoints matter in MASH drug screening?

Relevant endpoints depend on the therapeutic mechanism and the question the study is designed to answer. In MASH drug screening, useful endpoints may include lipid accumulation, inflammatory markers, fibrosis-related markers, viability, dose response, and treatment-related changes in disease phenotype.

For early screening, the goal may be to identify compounds that reduce steatosis or improve disease-associated readouts. For more advanced studies, the goal may be to understand the mechanism of action, compare monotherapies and combinations, or generate stronger translational evidence before moving toward later development stages.

Resources about InSphero's MASH Drug Screening

If you'd like to know more about InSphero's MASH Drug Screening, I encourage you to:

• Read our tutorial in Genetic Engineering and Biotechnology News. We take a closer look at experimental design considerations for selecting the most appropriate models for different types of experiments at various stages in the drug development pipeline, using an antisteatotic drug candidate as an example.
• Register for my webinar on Redefining NASH Discovery: A New Approach to Complex Disease Modeling. I'll show you how quickly and efficiently you can screen compounds and combination therapies using an in vitro platform—6x faster than mouse models—that reflects the full disease progression in humans —from fat accumulation in hepatocytes to inflammation and fibrosis of liver tissue. You'll also get a preview of RNASeq data that confirms the induction of the MASH phenotype in our model.

Watch this video to learn how we applied our scalable Akura™ technology and 10 years of experience in perfecting 3D in vitro human liver models to develop the first automation-compatible 3D in vitro human liver disease platform for NAFLD and NASH. And read about how pharma companies are applying this platform in their drug discovery programs.

Both Eva and I would love to hear your thoughts and welcome any suggestions for future topics you'd like us to cover in our blogs or upcoming webinars. Please use the comments section below to share your ideas!

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