Only 5% of therapies tested in animals reach human use

From when a therapy is tested on animals to its approval for human use there is a long journey and many of them fall by the wayside, according to a study indicating that only 5% achieve regulatory approval for use in people.

A study led by the University of Zurich and what publishes Plos Biology reviewed 122 biomedical research publications describing 54 human diseases and 367 therapeutic interventions.

The overall proportion of therapies moving from animal studies to human studies was 50%; 40% progressed to randomized controlled clinical trials and only 5% (one in 20 therapies) managed to obtain regulatory authorization from the authorities.

The average time frames to reach the various stages were five years to any human studies, seven years to randomized controlled trials, and 10 years to regulatory approval.

The work also concludes that there is agreement in the positive results in animal models and in humans in 86% of cases.

Animal studies are used in basic research to understand aspects of human diseases and have paved the way for certain therapeutic innovations, although there are several steps to follow before a treatment can be approved for human use.

In debates about the ethics of animal research, clinical translation is one of the main justifications for this type of work, despite the fact that there is little data on how many studies pass each step and are finally approved.

Although the number of studies that pass the first phase is greater than previous evidence suggested, The low final approval rate suggests that there could be deficiencies to be addressed in the design of studies both in animals and in the early clinical phases.

The authors advocate, to improve the translation of research, “for greater robustness in the design of studies in animals and humans, which will not only benefit experimental animals, but also affected patients.”

The investigator Lluís Montoliuof National Biotechnology Centerpointed out about the work, in which he did not participate, that it agrees with the authors' interpretation to explain that only 5% of animal studies are approved in humans.

That is to say, there are “limitations in the design of both experiments with animals and trials with people,” said Montoliu, quoted by the Science Media Centre, a resource platform for scientific journalism.

Experiments on animals continue to be necessary in biomedicine to advance the development of therapies to treat diseases that affect both animals themselves and humans.

But he considers that surely we should “try to improve experimental designs, both at a preclinical and clinical level, in order to increase the percentage of animal studies that are confirmed in humans.”

In another comment on the study, Jordi Gracia-Sancho, research professor at IDIBAPS-Hospital Clínic of Barcelona, ​​wrote that its conclusions should be taken “with caution,” since the analysis is based on an evaluation of already published review articles. and therefore, there may be some bias derived from the conclusions or opinions of the authors.”