Clinical trial highlights: Dopamine cell-replacement therapies.

Parkinson's disease is a common neurodegenerative disorder, which is characterised by motor features, many of which relate to the loss of the dopaminergic nigrostriatal pathway. The use of grafted cells to replace the lost dopaminergic neurons as a therapy for Parkinson's has been explored since the 1980s, with mixed clinical outcomes. Much of the heterogeneity in outcomes has been related to the major problems with the cell source for these trials, being derived from human fetal brain tissue. It is, however, now possible to derive authentic midbrain dopamine cells from human pluripotent stem cells and several first-in-human clinical trials are now underway to explore this approach.