Suzhou, China | April 14, 2026

XellSmart has announced the initiation of a multicenter Phase II clinical trial evaluating its iPSC-derived dopaminergic neural progenitor cell therapy (XS411) for the treatment of primary Parkinson’s disease. This milestone follows encouraging Phase I results demonstrating safety, tolerability, and early efficacy signals, positioning XS411 as a promising regenerative medicine approach aimed at addressing the underlying cause of neurodegeneration rather than merely managing symptoms. The trial, conducted in collaboration with leading institutions including Beijing Tiantan Hospital, reflects growing momentum in stem cell-based therapies for neurodegenerative diseases and highlights China’s advancing role in cutting-edge clinical innovation.

Phase II Trial Design Targets Efficacy and Long-Term Outcomes

The newly launched Phase II trial adopts a randomized, controlled, and blinded endpoint design, enrolling approximately 30 patients aged 50–75 years with clinically confirmed Parkinson’s disease. Participants will be assigned in a 2:1 ratio to receive either XS411 cell therapy or standard pharmacological treatment, with a 12-month primary evaluation period followed by extended follow-up to assess long-term outcomes up to 24 months post-transplantation.

This design aims to generate robust data on clinical efficacy, durability of response, and safety, providing a foundation for future Phase III registrational trials. The inclusion of a crossover opportunity for control group patients further enhances the ethical and scientific value of the study, ensuring broader access to the investigational therapy.

Promising Phase I Results Demonstrate Functional Recovery

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The progression to Phase II is supported by compelling Phase I clinical data, where patients receiving a single transplantation of XS411 demonstrated significant improvements in motor function and quality of life. Key efficacy measures, including the MDS-UPDRS Part III motor score, showed marked improvement beyond clinically meaningful thresholds. Patients experienced longer durations of “ON” time without dyskinesia, indicating enhanced daily functioning and symptom control.

Additionally, advanced imaging using 18F-DOPA PET-CT revealed increased dopamine activity in the brain, confirming successful cell engraftment, differentiation, and functional integration. Importantly, no serious adverse events related to the transplanted cells were reported, underscoring the therapy’s favorable safety profile.

iPSC Technology Drives Next-Generation Regenerative Medicine

At the core of XS411 is induced pluripotent stem cell (iPSC) technology, which enables the generation of dopaminergic neurons capable of replacing damaged cells in the brain. Parkinson’s disease is characterized by the progressive loss of these neurons, leading to debilitating motor symptoms such as tremors, rigidity, and impaired movement. Unlike traditional treatments that focus on dopamine replacement or symptom management, XS411 aims to restore neural function by repairing damaged circuits. This allogeneic, off-the-shelf therapy overcomes historical limitations associated with earlier cell transplantation approaches, including ethical concerns and limited cell availability. By leveraging scalable and standardized cell production, XellSmart is advancing a new paradigm in treating neurodegenerative disorders.

The launch of the Phase II trial by XellSmart marks a significant step forward in the development of cell-based therapies for Parkinson’s disease, highlighting the transformative potential of iPSC-derived regenerative medicine. With strong early clinical evidence and a robust trial design, XS411 represents a promising candidate for addressing one of the most challenging neurological disorders. As global prevalence of Parkinson’s disease continues to rise, innovative approaches like this could redefine treatment strategies, offering renewed hope for patients and advancing the frontier of neuroscience and clinical therapeutics.

Source: XellSmart press release