Resolving Ethical Issues in Stem Cell Clinical Trials: The Example of Parkinson Disease

Abstract

Stem cells derived from pluripotent cells offer the hope of new treatments for diseases for which current therapy is inadequate. Clinical trials are essential in developing effective and safe stem cell therapies and fulfilling this promise. However, such clinical trials raise ethical issues that are more complex than those raised in clinical trials using drugs, cord blood stem cells, or adult stem cells. Several clinical trials are now being carried out with stem cells derived from pluripotent cells, and many more can be expected in light of the rapid scientific progress in the field.Degenerative neurological diseases are desirable targets for stem cell clinical trials. The FDA has approved Phase 1 clinical trials of neural stem cell transplantation for Batten Disease, Pelizaeus-Merzbacher Disease, and spinal cord injury. In Parkinson Disease (PD), stem cell transplantation could correct the primary pathophysiological defect — inadequate levels of the neurotransmitter dopamine. Current treatment is unsatisfactory in late-stage PD.