For decades, animal models have served as the primary gateway for biomedical research and drug development. However, the high failure rate of drugs in human clinical trials—estimated at 92% for all drugs entering the U.S. system—has fueled criticism regarding the reliability of animal surrogates. Researchers are increasingly turning to New Approach Methodologies (NAMs), which include organoids, organ-on-a-chip systems, and artificial intelligence to model human biology more accurately than mice or monkeys.

One prominent example is the 'lung-on-a-chip' technology. Developed at Harvard University’s Wyss Institute, these devices use microfluidic channels lined with human cells to mimic the mechanical forces of breathing. Unlike static tissue cultures, these chips can simulate inflammatory responses to bacteria and the absorption of nanoparticles. While these technologies have existed for years, their adoption has been hindered by a regulatory environment that historically mandated animal data. This is beginning to shift; in 2026, the FDA issued a rule to replace 'animal tests' with the broader term 'nonclinical tests' in drug-development regulations, explicitly opening the door for validated human-cell systems and computer models.

A person's hand holding a small clear plastic organ-on-a-chip device with internal channels.
A handheld organ-on-a-chip device demonstrates the miniaturized scale of microfluidic systems used to mimic human organ functions.spectrum.ieee.org

This image illustrates the 'lung-on-a-chip' and similar microfluidic technologies mentioned in the second paragraph.

Despite this regulatory progress, the transition faces significant engineering and logistical hurdles. To be accepted by agencies like the FDA, these systems must move beyond academic prototypes to become mass-produced commercial products that meet strict performance criteria. Variations in materials, such as the hydrogels used as tissue scaffolds, can significantly alter cell growth patterns, making standardization a primary challenge. Furthermore, experts note that the shift is as much about 'change management' as it is about technology, requiring a fundamental update to institutional culture, training, and international policy alignment to fully replace animal models in the research pipeline.