Only one in 20 therapies tested on animals ends up being authorized for humans, according to an unprecedented review study from the University of Zurich. This compiled the results of 122 studies on 367 different therapies for 54 human diseases.
‘It doesn’t seem like much, but some therapies can be life-saving for some people,’ Benjamin Ineichen, head of the study published in the specialist journal ‘PLOS Biology’, told Keystone-ATS.
Researchers have known for a long time that the proportion was low, but this is the first time that reliable figures have been available.
Half of these 367 therapies tested on laboratory animals led to clinical research on humans. 40% in so-called randomized and controlled studies. Such studies are considered the ‘gold standard’ of clinical research. They are conducted with placebo therapies and neither participants nor researchers know whether a study participant received a placebo or a real therapy.
It took on average five years to carry out a first human trial, seven years for randomized controlled trials and ten years to obtain authorization from the authorities. In some cases, it can even take several decades before a therapy is tested on humans.
‘False positives’
The researchers further showed that there was high concordance between animal studies and human studies: 86% of therapies successfully tested on animals were also effective in humans.
Despite this, after ten years, 95% of therapies tested on animals have never been authorized for humans. ‘It is very likely that a lack of quality in some animal studies has led to false positive results, i.e. the data suggests a therapeutic effect when in reality there is none. not,’ Ineichen explained. ‘This has the consequence that these drugs are then rejected during very rigorous tests on humans’
So are animal experiments useless? No study can really answer this question, according to Mr. Ineichen. ‘At the end of the day, it’s always a weighing of different interests,’ he noted.
/ATS
