Clinical Trials - Why There Aren't More Of Them

Aside from all the scientific/technical problems with growing and differentiating pluripotent cells, and the ethical grey area regarding human ESCs, there are additional problems on how best to set up a clinical trial for stem cells and how to interpret the data. Unlike standard clinical trials for drugs or medical devices, which have clear and widely accepted parameters for evaluation, people simply don't know how to assess stem cell treatments. Nobody has taken the lead in standardizing the criteria, and each investigator/sponsor has basically used their best judgment when designing such studies. The first problem with this model is the confusion it causes when comparing studies to determine safety and efficacy, because there may be few common points to compare. It leads to further regulatory problems as policy makers and regulators play whack-a-mole in their attempt to safeguard public safety by implementing ever-changing guidelines for stem cell trials. This regulatory uncertainly has discouraged potential sponsors from even attempting such studies, which are far more expensive to run than typical drug trials because of the higher initial costs, the lengthier duration of the study, and the greater risk for unforeseen side effects. Even if the treatment was proven safe and effective, it may only benefit a small portion of the population and so may not be profitable enough to offset the costs of research, development, and trials. Lastly, let's not forget that only a few countries in the world would allow the use of human stem cells for treatment, and the international regulatory nightmare that goes with that.

The news isn't all bad. There is an increasing push for international collaboration to speed up stem cell trials. There is also a new determination from stem cell research societies to standardize guidelines within each country and harmonize those guidelines globally. They are attempting to set up a global network that will not only drive research and development of pluripotent cells for treatment, but also transfer that knowledge into the clinic by creating a streamlined regulatory process. I think the term "global community" just took on another meaning.

Image credit: impactlab.net

Further reading:

Martell K, et al. Stem Cell Therapies in Clinical Trials: Workshop on Best Practices and the Need for Harmonization. Cell Stem Cell (7)4, 451-454 (2010).

Trounson A, et al. Developing a Case Study Model for Successful Translation of Stem Cell Therapies. Cell Stem Cell (6)6, 513-516 (2010).

George B. Regulations and guidelines governing stem cell based products: Clinical considerations. Perspect Clin Res. 2(3), 94-9 (2011)