Stem cells in the clinic

Abstract

Treatments that aim to alleviate the symptoms of Parkinson’s disease (PD) are only effective at the early stages and eventually lead to complications. Sawamoto et al. conduct an open-label, phase 1/2 clinical trial to test induced pluripotent stem (iPS) cell-derived dopaminergic cells as a therapeutic approach for PD.

The researchers bilaterally transplanted allogeneic iPS cell-derived dopaminergic progenitors into seven patients with PD, in which three received a low-dose treatment (2.1 –2.6 × 10⁶ cells per hemisphere), four received high-dose treatment (5.3–5.5 × 10⁶ cells per hemisphere), and all patients received tacrolimus as an immunosuppressant. No serious adverse events were detected, and MRI imaging revealed a gradual increase in the graft volume over 24 months, with no tumour-like features. Although the major purpose of the trial was to assess safety, Sawamoto et al. also reported some overall symptom improvements, thus providing data on the potential efficacy of the approach.