How human tissue models could transform preclinical drug development

At the same time, scientific, ethical and political momentum is building around the development of alternatives to animal testing. Governments and regulators across the world are beginning to support approaches that reduce reliance on animals while improving the quality and relevance of preclinical data. Among the most promising of these innovations are human tissue platforms – advanced laboratory-grown systems designed to replicate the structure and function of real human organs and tissues. These platforms are a powerful example of how biotechnology could reshape the future of drug testing.

Drug development remains one of the most expensive and uncertain processes in science. Bringing a single therapy to market can take more than a decade and cost tens of millions of dollars.2 Much of this expense comes from failure during clinical trials, when treatments that performed well in preclinical testing fail to demonstrate safety or efficacy in real human patients. A major reason for this disconnect lies in the biological differences between animals and humans. Although animal models can mimic certain aspects of human physiology and disease, they cannot fully reproduce the complexity of human biological systems. Drugs may behave differently across species because of variations in metabolism, immune responses, tissue structure and molecular pathways. This creates a significant challenge for pharmaceutical companies. A therapy that appears safe in animals may later produce harmful side effects in humans, while potentially effective drugs may be discarded because animal studies fail to reveal their full potential.

Muscle toxicity provides a good example of this issue. In preclinical safety studies using animal models, skeletal muscle is disproportionately one of the most commonly affected organs. Detecting muscle-related side effects early is therefore critical during development. However, conventional animal testing does not always provide an accurate picture of how human muscle tissue will respond to a drug candidate. As a result, researchers are increasingly exploring human-relevant systems that can generate more clinically meaningful data earlier in the development process.

Recent advances in tissue engineering, biomaterials and cell culture technologies are enabling scientists to recreate increasingly sophisticated models of human tissue in the laboratory. These systems are often referred to as human tissue platforms, organoids or engineered tissues. Rather than relying on whole-animal experiments, researchers can study drug responses directly in human-derived cells and tissues under controlled laboratory conditions. This provides an opportunity to generate data that may be more predictive of human outcomes than traditional animal studies alone. Human muscle models represent one of the most advanced examples of this approach. Developed using real human muscle cells obtained from donor tissue samples, these systems are designed to replicate the structure and behaviour of skeletal muscle as closely as possible. Importantly, these engineered tissues do not simply resemble muscle visually. Researchers have demonstrated through anatomical and functional assessment techniques that laboratory-grown muscle can develop the same structure and behaviour as native human skeletal muscle. The tissues closely resemble real muscle architecture, while biologically they respond to stimulation and drug exposure in ways that mimic human physiology.

Creating these models requires far more than simply growing cells in a dish. Scientists must recreate the conditions that allow muscle tissue to mature and function correctly. This involves combining human-derived cells with specialised biomaterials, growth factors and mechanical stimulation systems that encourage the tissue to organise into functional muscle fibres. The result is a laboratory platform capable of reproducing key aspects of human muscle biology in a highly controlled and measurable way.

One of the most significant advantages of human tissue platforms like muscle models is their potential to improve the predictive power of preclinical testing. Traditional animal studies often require researchers to administer a compound and wait for physiological changes to emerge over time. Human muscle systems, by contrast, allow scientists to observe cellular responses directly in human-derived tissue. Researchers can rapidly measure toxicity, contractile function, structural damage and other biological changes following drug exposure. This can provide earlier and more clinically relevant insight into how a therapy may behave in patients. By identifying safety concerns earlier, researchers may be able to reduce costly late-stage failures during clinical development. At the same time, compounds that demonstrate positive responses in human tissue systems may progress through development with greater confidence.

The potential applications of human muscle models extend beyond safety screening alone. Because these systems are derived from human tissue, they also offer researchers a powerful tool for studying disease biology itself. Many current platforms are built using samples from healthy donors, enabling scientists to establish baseline models of normal muscle physiology. In the future, it may become possible to generate muscle models using tissue from patients with inherited muscular disorders, neuromuscular diseases or age-related degenerative conditions. Scientists could potentially recreate aspects of diseases such as muscular dystrophy or motor neurone disease in the laboratory, providing an opportunity to study pathological mechanisms directly in human tissue. This could transform how researchers investigate disease progression and identify therapeutic targets.

The growing interest in human-derived tissue platforms is taking place alongside wider efforts to reduce animal use in scientific research. For many years, researchers and policymakers have worked within the framework of the ‘3Rs’: replacement, reduction and refinement.3 These principles aim to replace animals where possible, reduce the number used and refine experimental methods to minimise suffering. Recent statistics suggest meaningful progress is being made. In Great Britain, the number of scientific procedures involving living animals fell from more than four million in 2015 to approximately 2.64 million in 2024, the lowest level recorded since 2001.4 Similar reductions have been observed across Europe. Regulatory attitudes are also evolving. In the US, the Food and Drug Administration has announced plans to make animal testing the exception rather than the norm in drug safety and toxicity testing over the coming years.5 The UK government has similarly pledged funding to accelerate the development of alternative methods, while the European Commission is developing strategies aimed at reducing animal testing in chemical safety assessments.

Despite this momentum, a complete transition away from animal testing will not happen overnight. Animal studies remain deeply embedded within international regulatory frameworks designed to protect patient safety. Any alternative approach must demonstrate robust scientific evidence before it can achieve widespread acceptance. For now, the greatest impact of human tissue platforms may lie in refinement and reduction rather than outright replacement. By enabling researchers to answer certain biological questions earlier using human-derived systems, tissue models can help streamline the experimental process. Studies that previously required multiple rounds of animal experimentation may instead be narrowed down using laboratory-grown human tissues first. Researchers can identify ineffective or toxic compounds earlier, reducing the number of animal studies ultimately required. In practical terms, this creates a more targeted and efficient research pathway while simultaneously improving the relevance of the data being generated.

The movement towards human-relevant drug testing technologies represents more than an ethical response to concerns about animal welfare. It also reflects a growing recognition that more human-centred science may ultimately produce better medicines. Human tissue platforms are not yet capable of fully replicating the complexity of the human body. Despite the development of ‘organ-on-a-chip’ technology, entire physiological systems remain difficult to model in vitro. As a result, animal studies are likely to continue playing a role in some areas of biomedical research for the foreseeable future. Nevertheless, the direction of travel is clear. Advances in tissue engineering, stem cell biology, biomaterials and biofabrication are rapidly improving the sophistication of laboratory-grown human systems. Models are becoming more physiologically realistic, more reproducible and more scalable for industrial use. Human muscle platforms provide a strong example of this progress. By replicating key structural and functional features of skeletal muscle, they offer researchers an opportunity to study drug responses directly in human tissue, generating faster and potentially more predictive data than conventional approaches alone.

As scientific validation grows and regulatory frameworks evolve, these technologies could fundamentally reshape the early stages of drug development. While the transition will likely be gradual, the combination of technological innovation, regulatory support and increasing demand for better models suggests that the future of preclinical testing may look very different from the past. For researchers, pharmaceutical companies and patients, that transformation could mark the beginning of a more efficient, more ethical and ultimately more human-centred era in medicine.

Professor Mark Lewis is co-founder and chief executive officer of Myomaker Bio. He has held leadership positions in a number of academic institutions in different spheres of the higher education sector while maintaining his status as a fully research-active academic. He has been involved in line, change and group management and also held a number of directorships and consultancies with companies in the life sciences sector, including involvement in multiple projects in a leadership capacity within these roles. Alongside this, he has dedicated more than 25 years to the development and applications of human muscle organs. He has authored and co-authored over 50 publications in the skeletal muscle field.

How human tissue models could transform preclinical drug development

The limitations of traditional preclinical models

The rise of human tissue platforms

Improving predictive power in drug development

Beyond toxicity testing

Supporting the transition away from animal testing

A gradual but transformative shift