Kenai RNDP-001 Dopaminergic Progenitor Cell Therapy for Parkinson's Disease (NCT07106021)

Kenai RND-P001 PD NCT07106021

Overview

Kenai Therapeutics is conducting a pioneering Phase 1b/2a clinical trial evaluating RNDP-001, a human dopaminergic progenitor cell therapy for patients with idiopathic Parkinson's disease. This trial represents a transformative approach in cell replacement therapy, aiming to restore dopaminergic function through surgical implantation of allogeneic stem cell-derived dopaminergic progenitors directly into the putamen. Unlike previous therapeutic approaches that focus on neuroprotection or symptomatic relief, RNDP-001 aims to replace lost dopaminergic neurons, potentially offering disease-modifying benefits for Parkinson's disease patients["@kenai2025"].

Kenai RND-P001 PD NCT07106021

Overview

Kenai Therapeutics is conducting a pioneering Phase 1b/2a clinical trial evaluating RNDP-001, a human dopaminergic progenitor cell therapy for patients with idiopathic Parkinson's disease. This trial represents a transformative approach in cell replacement therapy, aiming to restore dopaminergic function through surgical implantation of allogeneic stem cell-derived dopaminergic progenitors directly into the putamen. Unlike previous therapeutic approaches that focus on neuroprotection or symptomatic relief, RNDP-001 aims to replace lost dopaminergic neurons, potentially offering disease-modifying benefits for Parkinson's disease patients["@kenai2025"].

This trial comes at a critical time in Parkinson's disease therapeutic development. While current treatments effectively manage symptoms for many years, they do not address the underlying loss of dopaminergic neurons in the substantia nigra pars compacta. Cell replacement therapy offers the potential to not just slow or stabilize the disease, but potentially reverse some of the neurological damage by reconstituting the dopaminergic system that is progressively lost["@Lindberg2018"].

The trial is sponsored by Kenai Therapeutics with substantial funding support from the California Institute for Regenerative Medicine (CIRM)[@cirim]. The involvement of CIRM, California's stem cell agency, provides both credibility and financial resources to advance this innovative therapy through clinical development.

Parkinson's Disease Background

Disease Pathology

Parkinson's disease is the second most common neurodegenerative disorder after Alzheimer's disease, affecting approximately 10 million people worldwide. The disease is characterized by[@Kalia2015]:

• Motor Symptoms: Resting tremor, bradykinesia, rigidity, and postural instability
• Non-Motor Symptoms: Sleep disorders, depression, constipation, hyposmia, and cognitive impairment
• Neuropathology: Loss of dopaminergic neurons in the substantia nigra pars compacta and presence of Lewy bodies (alpha-synuclein inclusions)

Current Treatment Limitations

Current Parkinson's disease therapies have significant limitations:

• Levodopa: Loses efficacy over time, with motor complications (dyskinesias) developing in many patients
• Deep Brain Stimulation: Requires invasive surgery and is not suitable for all patients
• Neuroprotective Therapies: No approved therapies have demonstrated clear disease-modifying effects
• Progressive Disability: Despite optimal medical therapy, most patients experience progressive disability over 10-15 years

Rationale for Cell Therapy

Cell replacement therapy addresses the root cause of Parkinson's disease—the loss of dopaminergic neurons:

• Neuron Replacement: Transplanting functional dopaminergic neurons to replace those lost to degeneration
• Dopamine Production: New neurons can produce and release dopamine locally
• Circuit Reconstruction: Potential for newly implanted neurons to integrate into existing neural circuits
• Disease Modification: Unlike symptomatic treatments, addresses the underlying neurobiology

Trial Details

| Property | Value |
|----------|-------|
| Phase | Phase 1b/2a |
| Status | Recruiting |
| Drug | RNDP-001 (human dopaminergic progenitor cells) |
| Sponsor | Kenai Therapeutics |
| ClinicalTrials.gov Identifier | NCT07106021 |
| Study Name | RNDP-001-02 |
| Indication | Idiopathic Parkinson's Disease |
| Enrollment | 12 patients (estimated) |
| Start Date | July 17, 2025 |
| Primary Completion | September 2027 (estimated) |
| Study Completion | June 2031 (estimated) |
| Duration | 15 months follow-up |
| Randomization | Dose escalation design |

Mechanism of Action

Cell Replacement Strategy

RNDP-001 represents a cell replacement therapy approach to Parkinson's disease that aims to reconstitute the damaged dopaminergic system:

Differentiation Protocol

The development of dopaminergic progenitors follows a sophisticated differentiation process:

• Pluripotent Stem Cell Starting Material: Human embryonic stem cells (hESCs) or induced pluripotent stem cells (iPSCs)
• Directed Differentiation: Growth factors and small molecules guide cells toward dopaminergic lineage
• Midbrain Specification: Protocols emulate development of substantia nigra pars compacta neurons
• Purification: Progenitors are enriched for expression of markers including LMX1A, FOXA2, and TH
• Quality Control: Each lot undergoes extensive characterization for identity, potency, and safety

Maturation and Integration

Following implantation, the progenitor cells are expected to:

• Mature: Differentiate into fully functional dopaminergic neurons
• Extend Processes: Project axons to appropriate target regions in the striatum
• Establish Synapses: Form functional synapses with host neurons
• Produce Dopamine: Synthesize and release dopamine in response to physiological signals
• Integrate: Receive synaptic input from host neurons, becoming part of the nigrostriatal circuit

Surgical Delivery

The cells are delivered using a specialized Syringe Front-Loading Device designed for precise neural cell implantation:

Dose Groups

The trial uses a sequential dose escalation design with three dose groups:

| Group | Description | Dose Level | Safety Focus |
|-------|-------------|------------|---------------|
| First patient group | Low dose | Initial dose cohort | Primary safety assessment |
| Second patient group | Higher dose | Escalated dose | Dose-response relationship |
| Third patient group | Best dose | Optimal dose based on safety/efficacy | Confirmatory |

This design follows established principles for first-in-human cell therapy trials, starting with the lowest expected therapeutic dose and escalating based on safety review[@Barker2015].

Stem Cell Therapy Background

Historical Context

Cell replacement therapy for Parkinson's disease has a long history:

• 1979: First fetal tissue transplants in rodents
• 1987: First human fetal tissue transplants
• 1990s: Multiple trials of fetal ventral mesencephalic transplants
• 2000s: Mixed results from controlled trials, with some patients showing benefit but others experiencing dyskinesias
• 2010s: Development of stem cell-derived dopaminergic neurons
• 2020s: First-in-human trials of pluripotent stem cell-derived neurons

Advances in Cell Therapy

The field has advanced significantly:

• Pluripotent Stem Cells: Human ESCs and iPSCs provide unlimited source of dopaminergic neurons[@Takahashi2007]
• Defined Protocols: Highly reproducible differentiation procedures
• Cell Purity: Advanced sorting and enrichment techniques
• Safety: Gene editing and screening reduce risks of tumor formation
• Standardization: Master cell banks enable consistent product manufacturing

Advantages of RNDP-001

This approach offers several potential advantages:

• Off-the-shelf Availability: Unlike autologous iPSC approaches, can be manufactured in advance
• Standardized Dosing: Consistent cell product allows precise dosing
• Young Cells: Cells are derived from young donors, potentially offering better survival
• Scalable Manufacturing: Can produce sufficient cells for widespread clinical use

Inclusion Criteria

• Diagnosis of idiopathic Parkinson's disease consistent with the Movement Disorders Society Clinical Criteria
• Age 45 to 75 years
• Disease duration 5-15 years from diagnosis
• MMSE score ≥ 24 (no significant cognitive impairment)
• Stable Parkinson's disease medications for ≥3 months
• Medically stable to undergo a surgical procedure
• Able to provide informed consent

Exclusion Criteria

• Known Parkinson's disease gene mutation or variant (e.g., [LRRK2](/genes/lrrk2), [GBA](/genes/gba), [SNCA](/genes/snca)) — to ensure idiopathic PD population
• Previous infusion therapy or surgery for Parkinson's disease (e.g., gene therapy, deep brain stimulation)
• History of allergic reaction or intolerance to an immunotherapeutic agent
• Contraindication to MRI
• Clinically significant medical conditions likely to interfere with the surgical procedure or study assessments
• Active malignancy or history of malignancy within 5 years
• Significant psychiatric disease
• Active participation in other clinical trials

Outcomes

Primary Outcomes

| Measure | Description | Timeframe |
|---------|-------------|-----------|
| Safety and Tolerability | Incidence of adverse events (AEs), serious AEs, AEs of special interest, and patient withdrawals | Baseline to 15 months post-transplant |
| Treatment-Emergent Adverse Events | Frequency and severity of AEs related to treatment | Throughout study |

Secondary Outcomes

| Measure | Description | Timeframe |
|---------|-------------|-----------|
| Quality ON time | Changes from Baseline measured by PD diary (patient-reported) | Baseline to 15 months post-transplant |
| Motor Function | MDS-UPDRS scores in ON and OFF medication states | Baseline to 15 months |
| Dopaminergic Function | Changes in F-DOPA-positron emission tomography (PET) | Baseline to 15 months |
| Quality of Life | PDQ-39 and EQ-5D-5L | Baseline to 15 months |
| Cognitive Function | MoCA and detailed neuropsychological testing | Baseline to 15 months |
| Dyskinesias | Rush Dyskinesia Rating Scale | Baseline to 15 months |

Exploratory Outcomes

• Biomarker studies (alpha-synuclein, neurofilament light chain)
• Neuroimaging (MRI to assess graft survival)
• Pharmacokinetic assessments

Study Locations

| Institution | Location | Status |
|------------|----------|--------|
| University of Arizona | Tucson, AZ | Recruiting |
| Keck Medical Center of University of Southern California | Los Angeles, CA | Recruiting |
| The Ohio State University Wexner Medical Center | Columbus, OH | Recruiting |

Contact Information

• Sponsor Email: patients@kenaitx.com
• University of Arizona: Marisa Valletta — COM-Neurosurgtrials@arizona.edu — (520) 626-7322
• Ohio State University: Caitlyn Evanovich — Caitlyn.Evanovich@osumc.edu — (614) 366-1648

Regulatory Status

• FDA Regulated: Yes (IND drug)
• Unapproved Device: Yes (delivery device)
• Data Monitoring Committee: Yes — independent committee monitoring safety data
• Regulatory Interactions: Fast Track designation may be pursued pending results

Risks and Safety Considerations

Surgical Risks

• Intracranial hemorrhage
• Infection
• Cerebrospinal fluid leak
• headache

Cell Therapy Risks

• Immune rejection (allogeneic cells)
• Tumor formation (theoretical risk)
• Dyskinesias (as seen in historical fetal transplant trials)
• Graft failure or insufficient engraftment
• Inflammation or immune response to cells

Monitoring

• Regular neurological examinations
• MRI brain imaging at key timepoints
• PET imaging to assess graft function
• Comprehensive safety laboratory testing

Comparison with Other Approaches

Gene Therapy Approaches

This trial represents one of several regenerative approaches for Parkinson's disease being investigated:

• [AB-1005 GDNF Gene Therapy](/clinical-trials/ab-1005-gdnf-gene-therapy-regenerate-pd) — Gene therapy to express GDNF in the putamen
• AAV2-GDNF — Adeno-associated virus delivery of GDNF
• AAV2-AADC — Gene therapy to enhance L-DOPA conversion

• Gene therapy ([AB-1005](/clinical-trials/ab-1005-gdnf-gene-therapy-regenerate-pd)) delivers genes that cause the brain to produce neurotrophic factors
• Cell therapy (RNDP-001) transplants actual dopamine-producing cells into the brain

Stem Cell Approaches Worldwide

Multiple groups are developing stem cell therapies for PD:

• International Stem Cell Initiative: Developing pluripotent stem cell-derived dopamine neurons
• Japanese Trials: Kyoto University and others conducting iPSC-derived cell trials
• European Consortium: EU-funded research on stem cell therapy
• US Trials: Multiple groups advancing toward clinical translation

Future Directions

Potential Indications

If successful, this therapy could potentially be applied to:

• Other parkinsonian syndromes (with caution regarding specific pathologies)
• Early-stage Parkinson's disease (before extensive neuron loss)
• Combination with other regenerative approaches
• Pediatric populations with genetic forms of Parkinsonism

Manufacturing Scale-Up

Successful trials will require:

• Expansion of manufacturing capacity
• Development of cryopreservation protocols
• Optimization of delivery devices
• Establishment of quality control standards

Related Mechanisms and Pages

This trial relates to several key NeuroWiki pages:

• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Dopaminergic Neurons](/cell-types/dopaminergic-neurons)
• [Cell Therapy for Parkinson's](/therapeutics/cell-therapy-parkinsons)
• [Neuroprotection](/therapeutics/neuroprotection)
• [GDNF Pathway](/proteins/gdnf-protein)
• [LRRK2 Pathogenesis](/mechanisms/lrrk2-pathogenesis)
• [GBA and Parkinson's](/genes/gba)

References