How AI is Improving Animal Use in Preclinical CRO Research

The ethical use of animals in research has always been a cornerstone of modern science. The 3Rs, Replace, Reduce, and Refine, developed over 50 years ago, form the global standard for humane and responsible practices. For a preclinical CRO, honoring these principles is rooted in compliance and serves as a commitment to advancing both science and ethics.
Today, artificial intelligence (AI) is helping shape that commitment into the modern era. By reshaping how studies are designed, monitored, and analyzed, AI is enabling preclinical CROs to improve animal welfare while accelerating the pace of drug discovery.
Replace: Smarter Alternatives for Preclinical CROs
The ultimate aim of the 3Rs is to replace animal models whenever possible. With the FDA Modernization Act 2.0 formally recognizing in vitro, in silico, and microphysiological systems as valid nonclinical tests, AI is accelerating this shift. By supporting virtual screening and predictive modeling, AI reduces reliance on animal testing while maintaining scientific rigor.
Virtual Screening
AI can analyze massive compound datasets to flag likely failures early, reducing the need for extensive animal testing. For a preclinical CRO, this means faster and more efficient lead optimization. For example, a "virtual lab" developed at Stanford University used AI agents to generate 92 novel vaccine candidates in a matter of days, with human researchers doing just one percent of the work [1]. This demonstrates AI's potential to conduct early-stage research in a virtual environment, minimizing the need for physical and in vivo testing early in the screening process.
Organ-on-Chip
With AI processing their complex data, advanced human-mimicking systems become more reliable alternatives to animal studies. Biotech firm, Emulate, a leader in organ-on-a-chip technology, has demonstrated that their Liver-Chip has a higher predictive accuracy for human drug-induced liver injury [2]. This technology provides a preclinical CRO with a powerful tool to generate robust data to marry with data from animal models.
Reduce: Doing More with Fewer Animals for Preclinical CROs
Reduce focuses on minimizing the number of animals used in a study without compromising scientific validity. AI enables a more efficient and data-driven approach to experimental design.
Optimized Study Design
AI draws on literature and historical data to fine-tune parameters like sample size, dosage, and timing, preventing wasted animal use. This is where ModernVivo fits in. For a preclinical CRO, using an AI-powered platform to analyze vast amounts of research literature will identify the most efficient study parameters, making research more targeted and reducing the number of animals needed for a study.
Longitudinal Monitoring
AI-powered imaging enables repeat measurements in the same animal, eliminating the need for multiple test groups. US labs like The Jackson Laboratory have developed AI-powered home-cage monitoring systems for mice. These systems use deep learning algorithms to continuously track an animal's behavior and health in its own environment. This allows a preclinical CRO to gather a more comprehensive and authentic picture of the animal's health over time, reducing the need for multiple, one-off tests that would require different animals [3].
Refine: Elevating Care and Welfare for Preclinical CROs
Refine is about improving the care and procedures for animals to minimize pain, suffering, and distress. AI provides new ways for a preclinical CRO to monitor and improve animal well-being.
Continuous Monitoring
AI-enabled sensors track subtle signs of stress or pain in real time, triggering early interventions. At Cornell University, Jennifer Sun is applying AI to improve animal welfare by analyzing veterinary and video data. Her work aims to create automated systems that can detect subtle signs of illness or stress in animals, helping veterinarians and researchers provide earlier, more targeted care [4].
Automated Data Collection
Less human handling means less stress, more accurate data, and better living conditions. US-based biotech companies like Recursion are leveraging AI and automation in their "smart" vivaria to minimize human interference. Their platforms automate data collection from sensors and instruments, reducing the need for frequent human handling of animals. This not only minimizes stress for the animals but also generates more reliable data [5].
The Future: Ethical and Intelligent Preclinical CROs
AI is no longer just a technology upgrade; it's an ethical accelerator. For a preclinical CRO, integrating AI into workflows strengthens their commitment to the 3Rs, builds sponsor confidence, and advances research in a more humane way.
Solutions like ModernVivo are at the forefront, ensuring that the next generation of drug development is both scientifically rigorous and ethically responsible.
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References
- Stanford Medicine (2025). Stanford scientists develop "virtual lab" for AI-driven vaccine research. https://med.stanford.edu/news/all-news/2025/07/virtual-scientist.html
- Emulate (2025). Alternatives to animal testing in drug development. Retrieved from https://emulatebio.com/alternatives-to-animal-testing-in-drug-development/
- The Scientist (2025). AI-powered tech enables continuous lab animal monitoring. https://www.the-scientist.com/ai-powered-tech-enables-continuous-lab-animal-monitoring-72714
- Cornell University (2025). How can we use AI to improve animal welfare? A Q&A with Jennifer Sun. https://bowers.cornell.edu/news-stories/how-can-we-use-ai-improve-animal-welfare-qa-jennifer-sun
- Recursion (2025.). Modeling animal data for more efficient AI drug discovery.https://www.recursion.com/news/modeling-animal-data-for-more-efficient-ai-drug-discovery