Targeting chelatable iron as a therapeutic modality in Parkinson's disease

Area of Science:

• Neuroscience
• Biochemistry
• Pharmacology

Background:

• Iron deposition in the brain is implicated in Parkinson's disease (PD) pathogenesis.
• Oxidative stress, exacerbated by iron, contributes to neurodegeneration in PD.
• Current therapeutic strategies for PD primarily focus on symptomatic relief.

Purpose of the Study:

• To assess the pathophysiological role of iron in Parkinson's disease (PD) using a targeted chelation strategy.
• To evaluate the efficacy of deferiprone (DFP) in reducing oxidative damage and improving motor function in preclinical and clinical models of PD.
• To investigate DFP's impact on brain iron deposition and neuronal dopamine levels.

Main Methods:

• Translational studies involved cell and animal models systemically treated with deferiprone (DFP).
• Assessments included motor function, striatal dopamine levels (HPLC, MRI-PET), brain iron deposition (R2*-MRI), and markers of oxidative damage.
• A pilot, double-blind, placebo-controlled randomized clinical trial in early-stage PD patients using DFP (30 mg/kg/day) over 12 months with a delayed-start (DS) paradigm.

Main Results:

• DFP significantly reduced labile iron and oxidative damage in cells and animals, improving motor function and increasing striatal dopamine.
• Early-start PD patients (n=19) showed significantly earlier and sustained improvements in substantia nigra iron deposits (R2*-MRI) and motor scores (UPDRS) compared to DS patients (n=18).
• The treatment was well-tolerated, with the main adverse event being transient neutropenia in three patients.

Conclusions:

• A moderate iron chelation regimen with DFP, targeting regional brain iron without affecting systemic levels, represents a novel therapeutic approach for PD.
• The promising results from translational models and pilot clinical trials warrant comprehensive evaluation of DFP's symptomatic and disease-modifying potential in PD.