Autologous Cell Therapy Sasineprocel Demonstrates 12-Month Safety, Engraftment in Parkinson Disease

New 12-month data from the ongoing phase 1/2a ASPIRO trial (NCT06344026) suggest that sasineprocel (ANPD001; Aspen Neuroscience), an autologous induced pluripotent stem cell-derived dopaminergic neuron precursor cell therapy, was associated with continued safety and sustained clinical benefit in patients with Parkinson disease (PD).

In the first 8 treated patients, investigators reported numerical improvements across motor function, activities of daily living, patient-reported outcomes, and quality of life, while also showing imaging evidence of graft survival and engraftment.¹

Presented in a late-breaking oral session at the 2026 AD/PD International Conference in Copenhagen, the update expands on earlier ASPIRO findings reported in 2025.¹ The company plans to advance sasineprocel into phase 3 testing later this year, making the durability of these early findings especially relevant for clinicians following restorative approaches in PD.¹

12-Month Findings Build on Earlier 6-Month Signals

The new analysis included the first 8 treated patients in ASPIRO, with 4 receiving a lower dose and 4 receiving a higher dose of sasineprocel. At 12 months, both cohorts showed numerical improvement across commonly followed PD measures, with mean good ON time increasing by 2.1 hours in the low-dose group and 2.4 hours in the high-dose group.

Overall, mean MDS-UPDRS Part III OFF scores improved by 15.5 points and 13.5 points, respectively, while mean MDS-UPDRS Part II scores improved by 5.3 points and 2.3 points. Mean PDQ-39 scores improved by 51.6% in the low-dose cohort and 28.5% in the high-dose cohort, with several patients also reducing levodopa equivalent daily dose during follow-up.¹

Investigators also reported that FDOPA PET imaging showed cell survival and successful engraftment, adding biologic support to the observed clinical changes. In addition, real-time intraoperative imaging confirmed accurate placement of dopaminergic neuron precursor cells into the post-commissural putamen.¹

In the presentation, trial investigator Chad Christine, MD, noted in a statement that the findings support “the potential for sustained clinical benefit without the need for chronic immunosuppression,” emphasizing the therapy’s goal of restoring dopamine and rebuilding neural circuitry essential for movement.¹

Safety Profile Remained Favorable Through 1 Year

At 12 months, no serious surgical adverse events (AEs) and no severe graft-induced dyskinesia were observed. The company also reported no symptomatic hemorrhages or infarctions.¹

These findings are consistent with earlier 6-month ASPIRO data, which described the first 3 treated patients and similarly showed no hemorrhages, serious intraoperative or postoperative complications, or severe graft-induced dyskinesia.² The most commonly reported AE at that time was swollen tongue, along with other procedure-related events such as back pain, hypoesthesia, incision-site pain, musculoskeletal stiffness, tongue injury, and urinary retention.²

The 6-month analysis also demonstrated early efficacy signals, including a 45% mean improvement in MDS-UPDRS Part III OFF scores and a 71% improvement in MDS-UPDRS Part II scores, alongside reductions in OFF time and increases in good ON time.² The updated 12-month data extended these findings in a larger cohort and suggest that benefit may persist over time.¹

Sasineprocel’s Mechanism and Rationale

ASPIRO is an open-label, first-in-human, multicenter phase 1/2a study evaluating bilateral intracranial delivery of autologous iPSC-derived dopaminergic neuron precursor cells in patients with PD aged 50 to 70 years.³ The primary objective is safety and tolerability, with secondary outcomes assessing clinician- and patient-reported measures of disease severity.

Sasineprocel is generated from a patient’s own skin fibroblasts, which are reprogrammed into induced pluripotent stem cells and then differentiated into dopaminergic neuron precursor cells prior to intracranial delivery.¹ This autologous approach eliminates the need for chronic immunosuppressive therapy, which is often required with allogeneic cell therapies and can limit broader use.¹

Looking Ahead to Phase 3

The ASPIRO data remain early and are derived from a small, open-label cohort, limiting conclusions regarding dose response and long-term durability. Still, the combination of favorable safety, imaging-confirmed engraftment, and sustained improvements across multiple clinical endpoints strengthens the signal compared with earlier reports.¹

With plans to initiate a phase 3 trial later in 2026, the next stage of development will be critical in determining whether these findings can be replicated in a larger, controlled population.¹ For clinicians, the broader question remains whether autologous cell replacement strategies can deliver durable, clinically meaningful improvements in motor and functional outcomes in routine PD care.

REFERENCES
1. Aspen Neuroscience Announces Positive 12‑Month Data from its ASPIRO Clinical Trial in a Late‑Breaking Oral Presentation at the AD/PD™ 2026 International Conference on Alzheimer's and Parkinson's Diseases. News release. Aspen Neuroscience. March 18, 2026. Accessed March 18, 2026. https://www.prnewswire.com/news-releases/aspen-neuroscience-announces-positive-12month-data-from-its-aspiro-clinical-trial-in-a-latebreaking-oral-presentation-at-the-adpd-2026-international-conference-on-alzheimers-and-parkinsons-diseases-302716505.html
2. Fraint A, Larsen PS, Christine CW, et al. Safety, tolerability, and efficacy of intracranial delivery of autologous iPSC-derived dopaminergic precursors in moderate to advanced Parkinson disease. Parkinsonism Relat Disord. 2025;134:107630. doi:10.1016/j.parkreldis.2025.107630
3. ClinicalTrials.gov. A study of ANPD001 in Parkinson disease (ASPIRO). NCT06344026. https://clinicaltrials.gov/study/NCT06344026. Updated March 20, 2025. Accessed March 18, 2026.