Clinical Trials of Human Embryonic Stem Cells Expand

We are seeing the era of full clinical evaluation of stem cell therapies unfold. This week brings an announcement by Advanced Cell Technology in California that the FDA has approved two more clinical trials using human embryonic stem cells (hESC) for retinal transplantation in patients with severe opthamalogic disease. In the laboratory, the stem cells were differentiated into retinal cells. The cells are transplanted, and these initial infusions will asses safety and tolerability of the cells in these individuals. The first FDA-approved clinical trial of hESC was announced last fall by Geron in which the stem cells were differentiated into neuronal cells and transplanted into patients with spinal cord injury, in an attempt to restore motor activity and induce nerve repair. The clinical trials began with the FDA approval of the Geron trial in January, 2009, just after the start of the Obama administration, which had vowed to lift the Bush-era restrictions on research into hESC. An Executive Order was issued in March, 2009, which did exactly that, unambiguously:

For the past 8 years, the authority of the Department of Health and Human Services, including the National Institutes of Health (NIH), to fund and conduct human embryonic stem cell research has been limited by Presidential actions. The purpose of this order is to remove these limitations on scientific inquiry, to expand NIH support for the exploration of human stem cell research, and in so doing to enhance the contribution of America’s scientists to important new discoveries and new therapies for the benefit of humankind.

The full determination of the clinical promise of hESC therapies (or those derived from adult stem cells) will take years. But the field certainly cannot contend with an erratic regulatory climate and unsettled expectations, which is what has happened for nearly a decade.