The promise and perils of stem cell therapeutics

Abstract

Stem cells are the seeds of tissue repair and regeneration and a promising source for novel therapies. However, apart from hematopoietic stem cell (HSC) transplantation, essentially all other stem cell treatments remain experimental. High hopes have inspired numerous clinical trials, but it has been difficult to obtain unequivocal evidence for robust clinical benefit. In recent years, unproven therapies have been widely practiced outside the standard clinical trial network, threatening the cause of legitimate clinical investigation. Numerous challenges and technical barriers must be overcome before novel stem cell therapies can achieve meaningful clinical impact.

Figure 1. Clinical trials of major stem cell types

Pie chart indicating the relative numbers of open trials testing clinical interventions for hematopoietic, neural, mesenchymal, adipose, and embryonic stem cells, as listed on the US NIH website clinicaltrials.gov.

Figure 2. World-wide experimental trials of stem cell-based therapies

World map showing locations of open, closed and pending clinical trials of stem cell-based interventions as listed on US NIH website clinical trials.gov. The relative numbers of trials performed outside of the United States may indeed be markedly understated because of reporting bias at the US government clinical trials website.