Nilotinib for Parkinson's Disease

Nilotinib for Parkinson's Disease

Introduction

<table class="infobox infobox-therapeutic">
<tr>
<th class="infobox-header" colspan="2">Nilotinib for Parkinson's Disease</th>
</tr>
<tr>
<td class="label">Parameter</td>
<td>Details</td>
</tr>
<tr>
<td class="label">Sponsor</td>
<td>Georgetown University</td>
</tr>
<tr>
<td class="label">Design</td>
<td>Randomized, double-blind, placebo-controlled</td>
</tr>
<tr>
<td class="label">Duration</td>
<td>12 months</td>
</tr>
<tr>
<td class="label">Sample Size</td>
<td>75 patients</td>
</tr>
<tr>
<td class="label">Doses</td>
<td>150mg, 300mg daily vs.

Nilotinib for Parkinson's Disease

Introduction

<table class="infobox infobox-therapeutic">
<tr>
<th class="infobox-header" colspan="2">Nilotinib for Parkinson's Disease</th>
</tr>
<tr>
<td class="label">Parameter</td>
<td>Details</td>
</tr>
<tr>
<td class="label">Sponsor</td>
<td>Georgetown University</td>
</tr>
<tr>
<td class="label">Design</td>
<td>Randomized, double-blind, placebo-controlled</td>
</tr>
<tr>
<td class="label">Duration</td>
<td>12 months</td>
</tr>
<tr>
<td class="label">Sample Size</td>
<td>75 patients</td>
</tr>
<tr>
<td class="label">Doses</td>
<td>150mg, 300mg daily vs. placebo</td>
</tr>
<tr>
<td class="label">Primary Endpoints</td>
<td>Safety, tolerability</td>
</tr>
<tr>
<td class="label">Secondary Endpoints</td>
<td>Motor scores (MDS-UPDRS), CSF biomarkers</td>
</tr>
<tr>
<td class="label">Condition</td>
<td>Dose</td>
</tr>
<tr>
<td class="label">CML (approved)</td>
<td>400-600mg</td>
</tr>
<tr>
<td class="label">PD (trial dose)</td>
<td>150-300mg</td>
</tr>
<tr>
<td class="label">Drug</td>
<td>Primary Target</td>
</tr>
<tr>
<td class="label">Nilotinib</td>
<td>BCR-Abl/c-Abl</td>
</tr>
<tr>
<td class="label">Dasatinib</td>
<td>Multi-kinase (Src family)</td>
</tr>
<tr>
<td class="label">Bosutinib</td>
<td>BCR-Abl/Src</td>
</tr>
<tr>
<td class="label">Radotinib</td>
<td>BCR-Abl</td>
</tr>
<tr>
<td class="label">Biomarker</td>
<td>Purpose</td>
</tr>
<tr>
<td class="label">CSF α-syn phosphorylation</td>
<td>Target engagement</td>
</tr>
<tr>
<td class="label">CSF [NfL](/proteins/nfl-protein)</td>
<td>Neurodegeneration</td>
</tr>
<tr>
<td class="label">c-Abl activity</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">LRRK2 mutation status</td>
<td>Patient selection</td>
</tr>
</table>

Overview

Nilotinib (brand name Tasigna) is a BCR-Abl tyrosine kinase inhibitor originally developed for chronic myeloid leukemia (CML) that has been repurposed for Parkinson's disease based on its ability to inhibit c-Abl (Abelson tyrosine kinase). This kinase is hyperactivated in dopaminergic [neurons](/entities/neurons) in PD brains and promotes [alpha-synuclein](/mechanisms/alpha-synuclein) aggregation, mitochondrial dysfunction, and neuronal death. The repurposing of nilotinib represents an innovative approach to targeting disease-modifying mechanisms in Parkinson's disease rather than just symptomatic relief.

Mechanism of Action

Nilotinib works through multiple mechanisms relevant to Parkinson's disease pathophysiology:

1. c-Abl Inhibition

Nilotinib potently inhibits c-Abl tyrosine kinase, which is hyperactivated in PD brains. c-Abl phosphorylates several key substrates:

• Alpha-synuclein: Phosphorylation at Tyr-125, Tyr-133, and Tyr-125 promotes aggregation and toxicity
• Parkin: Phosphorylation impairs E3 ubiquitin ligase function, disrupting protein clearance
• LRRK2: Modulates kinase activity, affecting cytoskeletal function
• α-Synuclein: Promotes formation of toxic oligomers

2. Autophagy Enhancement

By inhibiting c-Abl, nilotinib promotes [autophagy](/entities/autophagy)-mediated clearance of toxic proteins:

• Increases lysosomal function
• Enhances clearance of [alpha-synuclein](/proteins/alpha-synuclein) aggregates
• Restores cellular protein homeostasis

3. Mitochondrial Protection

c-Abl inhibition protects mitochondria from stress-induced damage:

• Preserves complex I activity
• Reduces mitochondrial [ROS](/entities/reactive-oxygen-species) production
• Protects against mitochondrial depolarization
• Maintains ATP production

4. Neuroinflammation Modulation

• Reduces microglial activation
• Decreases pro-inflammatory cytokine release
• May protect dopaminergic neurons from inflammatory damage

Clinical Evidence

Phase I Study

• Design: Open-label, dose-escalation study
• Dose: 100mg, 200mg, 300mg daily
• Key Findings:
• All doses safe and tolerable
• Significant reduction in α-synuclein in CSF
• Improved motor scores in some patients

Phase II Trial (NCT03205488)

Results (Pagan et al., J Parkinsons Dis 2020):

• Low-dose nilotinib (150mg-300mg daily) was safe and tolerable
• Showed trends toward improved motor scores
• Decreased CSF biomarkers of neurodegeneration ([NfL](/proteins/nfl-protein)), α-syn)
• No serious adverse events attributed to drug

Open-Label Extension Study

• Patients who completed Phase II continued receiving nilotinib
• Long-term safety data collected
• Sustained biomarker improvements observed

Planned/Future Trials

• Combination studies: With dopamine agonists
• Prodromal PD: Earlier intervention
• Biomarker-enriched: Patient selection based on biomarkers

Dosage and Administration

In PD trials, nilotinib is used at much lower doses than for CML:

The lower dose is used to achieve CNS penetration while minimizing side effects. Pharmacokinetic studies suggest that 150-300mg achieves adequate brain concentrations for c-Abl inhibition.

Side Effects and Safety

Common Side Effects

• Nausea and vomiting (usually transient)
• Rash
• Headache
• Fatigue
• Elevated liver enzymes (transaminases)
• Thrombocytopenia

Serious Concerns

• QT prolongation: Rare but requires monitoring
• Cardiovascular effects: Monitor in patients with cardiac history
• Drug interactions: CYP3A4 substrate

Contraindications

• QTc prolongation
• Severe hepatic impairment
• Pregnancy/nursing

Comparison with Other Kinase Inhibitors

Biomarkers for Patient Selection

Potential biomarkers to predict treatment response:

Research Directions

See Also

• [Alpha-Synuclein Aggregation Pathway](/mechanisms/alpha-synuclein-aggregation-pathway)
• [Parkinson's Disease Treatments](/therapeutics)
• [c-Abl Inhibitors](/therapeutics/lrrk2-inhibitors)
• [Autophagy-Enhancing Therapies](/therapeutics/autophagy-enhancing-therapies)
• [Mitochondrial Dysfunction Pathway](/mechanisms/mitochondrial-dysfunction-pathway)
• [Tyrosine Kinase Inhibitors](/therapeutics/tyrosine-kinase-inhibitors-neurodegeneration)

External Links

• [ClinicalTrials.gov: Nilotinib Parkinson's](https://clinicaltrials.gov)
• [Georgetown University Research](https://www.georgetown.edu)
• [Michael J. Fox Foundation](https://www.michaeljfox.org/)

Background

The study of Nilotinib For Parkinson'S Disease has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

Allen Brain Atlas Resources

• [Allen Brain Atlas - Gene Expression](https://human.brain-map.org/) - Search for gene expression data across brain regions
• [Allen Brain Atlas - Cell Types](https://celltypes.brain-map.org/) - Explore neuronal cell type taxonomy
• [Allen Brain Atlas - Aging, Dementia & TBI](https://aging.brain-map.org/) - Data on aging and traumatic brain injury

References