The International Society for Stem Cell Research announced on July 9 the presentation of new clinical data from the STEM-PD Phase I/II clinical trial at the ISSCR 2026 Annual Meeting. The study reports 12-month outcomes evaluating a cryopreserved, off-the-shelf dopaminergic progenitor cell product derived from human pluripotent stem cells for the treatment of Parkinson's disease.
The findings provide insights into the safety, feasibility, and biological activity of stem cell-derived dopaminergic cell transplantation in patients with Parkinson's disease. This represents another step in translating regenerative medicine into treatments for neurodegenerative diseases.
"These data represent the culmination of decades of research aimed at translating stem cell biology into a clinically viable therapy," said Malin Parmar, Professor in Cellular Neuroscience at Lund University, Sweden, who presented the findings at the meeting. "They demonstrate that a stem cell-derived dopaminergic cell product can be manufactured, delivered, and evaluated within a rigorous clinical trial framework. More broadly, they show that regenerative medicine is moving beyond proof-of-concept and into a stage where stem cell-based therapies are being tested in patients for complex neurodegenerative diseases."
Parkinson's disease involves progressive loss of dopamine-producing neurons, leading to worsening motor symptoms over time. Current therapies improve symptoms but do not replace lost neurons as the disease progresses. Stem cell-based approaches aim to restore dopamine production by replacing these cells and may offer more durable treatment strategies.
The STEM-PD trial enrolled individuals with moderately advanced Parkinson's disease who continued to experience significant symptoms despite optimized medical therapy. Participants received transplanted human pluripotent stem cell-derived dopaminergic progenitor cells designed to replace lost dopamine-producing neurons.
Researchers will continue to follow participants in the STEM-PD trial to evaluate long-term safety and graft function. Future studies will examine durability of transplanted cells, identify which patients benefit most, optimize dosing, and improve functional integration into the brain. Investigators are also exploring strategies to reduce immune suppression needs using autologous grafts or engineered cells designed to avoid immune detection.
"This field has been driven by decades of work from scientists, clinicians, regulatory experts, medical ethicists, and patients who believed stem cell therapy could become a reality," Parmar added. "It is especially meaningful to present results that demonstrate how discoveries in stem cell biology are now being translated into clinical testing. For me personally, these findings build directly on pioneering work initiated in Lund more than 40 years ago when the concept of cell therapy for Parkinson's disease first began to take shape."
