Oryon Cell Therapies (“Oryon”), a clinical-stage biotechnology company focused on developing autologous neuron replacement medicines for Parkinson’s disease and other neurodegenerative disorders, announced new clinical and neuroimaging data from an ongoing Phase 1b/2a study evaluating its autologous dopaminergic neuron replacement therapy for Parkinson’s disease. The study is being conducted in collaboration with expertise across Mass General Brigham led by the Neuroregeneration Institute at McLean Hospital. Study participants received unilateral neuronal implants. The data show improvements in motor function, together with neuroimaging consistent with restoration of dopaminergic signaling in the transplanted brain region.

The data were reported in an oral presentation at the AD/PD™ 2026 International Conference on Alzheimer’s and Parkinson’s Diseases and Related Neurological Disorders in Copenhagen, by Penelope Hallett, Ph.D., Co-Director of the Neuroregeneration Institute at McLean.

Key findings:

• Well-tolerated
• No serious adverse events to date
• Early and meaningful motor improvement in all participants
• Continued improvement beyond six months in all participants
• Imaging evidence of increased dopaminergic signaling on the implanted side of the brain, that aligned with functional improvements
• Improvement in the Parkinson's Disease Questionnaire-39 (PDQ-39), a self-report questionnaire designed to measure the health-related quality of life for individuals with Parkinson's disease
• No need for immunosuppression

Clinical Improvements Observed in People with Parkinson’s Disease Receiving Therapy

Interim results from the first five participants showed substantial improvements in motor function. A sixth participant had not yet had their first post-implant assessment. In each of the first five participants, OFF-state MDS-UPDRS Part III motor scores decreased by approximately 29%–62% from baseline at assessments 6–18 months after treatment. Improvements were observed in core Parkinson’s motor symptoms, including bradykinesia, rigidity, and gait.

Most study participants also showed improvements in additional functional measures, including mobility assessments such as Timed Up and Go. Several also experienced reductions in levodopa equivalent daily dose (LEDD), indicating a reduced need for dopamine-replacement medication.

“These results provide encouraging evidence that replacing dopaminergic neurons may restore biological function in Parkinson’s disease,” said Dr. Hallett. “The alignment of clinical improvements, imaging evidence of dopaminergic activity, and reduced medication use suggests that the implanted neurons are integrating into the brain’s circuitry and helping restore function lost to the disease.”

Neuroimaging Biomarker Shows Dopaminergic Synapse Restoration

Dopamine transporter DaT-SPECT imaging demonstrated marked increases in dopaminergic signal within transplanted regions of the brain. In one patient, DaT signal in the implanted putamen increased more than five-fold at six months, compared with baseline, while the untreated side of the brain showed a decrease in signal.

“We are encouraged by these data from the first cohort in this clinical trial who received unilateral neuronal implants,” said Nikola Kojic, M.D., Ph.D., Oryon’s Co-Founder and Chief Innovation Officer. “In collaboration with the team at Mass General Brigham, we expect to begin bilateral implantations in a second cohort this quarter to test the hypothesis that outcomes will improve even further compared to those seen with unilateral implants."