N. Engl. J. Med. 382, 1926–1932 (2020)

A tailored therapy approach with induced pluripotent stem cells improved the symptoms of a patient’s Parkinson’s disease.

Parkinson’s disease is a progressive, debilitating disease and is linked to neuronal loss in the substantia niagra, which causes striatal dopamine deficiency. Approaches attempting to replace or regenerate these neurons have been studied for a long time; however, nothing has proven effective.

A group of researchers in the USA were able to derive induced pluripotent stem cells from a patient with Parkinson’s disease and were able to differentiate these into dopaminergic progenitor cells. Two separate transfers of these cells into the patient’s brain were made with no immunosuppressants. At 18–24 months after the transfers, there was an improvement in the patient’s symptoms without any adverse effects. The approach needs to be further tested in a clinical trial and needs to be analyzed after additional follow-up before it can be considered for clinical use.