This shift is largely driven by increased confidence in New Approach Methods (NAMs). These include AI-powered analysis, human-derived cell models and many more advanced computational tools that can predict drug safety and efficacy without relying on animal studies. In fact, the MHRA believes advances in this technology could see some medicines entering human trials without undergoing traditional animal testing at all.

This is not just a technological evolution, but a regulatory one as well. The new guidance introduces stricter limitations on when animal testing is allowed, reflecting the UK government’s broader ambition to phase out animal testing unless necessary. Drugs that are not pharmacologically active in animals, for example, can no longer be tested on them and toxicity studies will only be allowed where there is clearly a benefit to the animal.

Additionally, the MHRA is beginning to create a pathway for non-animal evidence. Developers using AI and other NAMs will be able to submit early data for regulatory review, which allows for a more iterative and collaborative approval process compared to the traditional linear and often rigid evidence requirements.

Success will increasingly depend on the ability to generate credible, human-relevant evidence using AI. However, this shift is also raising the bar for validation, as regulators will expect these methods to be robust, transparent and accurate.

For PV teams, the implications are just as important. Earlier, more accurate toxicity predictions could reduce late-stage failures and improve the quality of safety data in post-market monitoring. Though this is not the end of animal testing overnight, we still need new approaches to validation and oversight, but it is a clear signal of direction. Regulators are actively encouraging alternative methods. One day in the future, we may find the debate over the ethics of animal testing is largely finished.

“Advances such as AI-driven analysis and human-derived cell models mean some medicines no longer require animal studies.”

Julian Beach, MHRA Interim Executive Director