Look back in anger - what clinical studies tell us about preclinical work

Abstract

Misled by animal studies and basic research? Whenever we take a closer look at the outcome of clinical trials in a field such as, most recently, stroke or septic shock, we see how limited the value of our preclinical models was. For all indications, 95% of drugs that enter clinical trials do not make it to the market, despite all promise of the (animal) models used to develop them. Drug development has started already to decrease its reliance on animal models: In Europe, for example, despite increasing R&D expenditure, animal use by pharmaceutical companies dropped by more than 25% from 2005 to 2008. In vitro studies are likewise limited: questionable cell authenticity, over-passaging, mycoplasma infections, and lack of differentiation as well as non-homeostatic and non-physiologic culture conditions endanger the relevance of these models. The standards of statistics and reporting often are poor, further impairing reliability. Alarming studies from industry show miserable reproducibility of landmark studies. This paper discusses factors contributing to the lack of reproducibility and relevance of pre-clinical research.

The conclusion: Publish less but of better quality and do not rely on the face value of animal studies.

Fig. 1. Clinical trials are based on the pillars of basic research / pre-clinical drug development, and toxicology

Fig. 2. Typical problems commonly causing overinterpretation of results in basic research

Fig. 3. If the overall conclusion of an article depends on a number of experiments, each with an error rate of 5%, the overall probability of a non-chance result decreases steadily

Fig. 4. Karyograms of commercial CHO cells (parental) and CHO cells transfected with different CYP-450

Taken from the thesis work of Dr Alessia Bogni, co-supervised by Dr Sandra Coecke.