From bench to bedside: Difficulties in spinal cord injury clinical trials
In developing new treatments for any disease or disorder, translating lab results to clinical benefits is a major challenge. The ‘valley of death’ is research speak for this bridge between lab results and treating patients. Spinal cord injury research is no exception, with a chasm between lab-based research and clinical practice and is an even more treacherous and difficult bridge to cross than many other research fields
One thing is for certain: research isn’t predicting clinical trial results. This could be down to the simplified nature of preclinical models, or the diversity of patients. This means huge numbers of potential treatments are being put into clinical trials and tested at large expense many of which are unsuccessful. Is there a better way to predict which treatments are more likely to be successful?
In clinical trials preclinical testing is carried out on treatments using experimental models of spinal cord injury. Could it be that these models are insufficient at mimicking patients? Usually the models are based on observations of patients with spinal cord injuries, but they may not portray the whole picture of the complex injury process, and factors which are observable but not included in the model.
Furthermore, spinal cord injuries come in various forms. They could be from high impact road accidents in young populations, low impact falls in elderly populations, or non-traumatic causes such as cancers or degenerative disease. Clinical trials incorporate all of these patient groups and injury causes. If a drug does not work across all patient groups it is often discounted. However, it could be the case that a novel treatment does not work for all groups of patients and instead only helps in one type of injury or patient group. This finding may not be detected in large scale clinical trials, with the treatment discounted because of low success rates across a patients with different kinds of injuries.
Overall, the clinical trial methodology is in need of modernising and improving. We need to go back to the basics in order to develop and test treatments in the most efficient way possible. Better characterisation of injuries and understanding of the differences between patient populations and injury types is fundamental. Once researchers can gain this understanding, improved preclinical models can be developed and a stratified approach can be undertaken in clinical trials. Only then can we gain a real picture of what works and what doesn’t in new treatment for spinal cord injury.
This article was written by Katie Timms a PhD student at the University of Leeds at the Institute of Medical and Biological Engineering where she is researching spinal cord injury. You can reach her on twitter @KVTimms