Optimized pharmacological control over the AAV-Gene-Switch vector for regulable gene therapy

Area of Science:

• Neuroscience
• Pharmacology
• Gene Therapy

Background:

• Current gene therapy is irreversible, lacking control over therapeutic expression and side effects.
• The Gene-Switch (GS) system offers pharmacologically regulable neurotrophic factor expression for Parkinson's disease.
• Mifepristone controls GS vector expression but exhibits variable pharmacokinetics/dynamics across species and genders.

Purpose of the Study:

• To investigate formulation effects on mifepristone's activation of the GS system.
• To evaluate ritonavir as a booster to overcome mifepristone's pharmacokinetic/dynamic variability.
• To demonstrate GS system control in a humanized model accounting for human plasma protein interactions.

Main Methods:

• Assessed the impact of mifepristone formulation on GS system activation.
• Administered ritonavir as a pharmacological booster to enhance mifepristone efficacy.
• Utilized a "humanized" rat model expressing human α1-acid glycoprotein to mimic human physiology.

Main Results:

• Mifepristone formulation significantly influences GS system activation.
• Ritonavir robustly enhanced mifepristone's effect, overcoming species- and gender-specific variability.
• The GS vector was effectively controlled by mifepristone in the presence of human α1-acid glycoprotein in a humanized rat model.

Conclusions:

• Mifepristone formulation and ritonavir co-administration significantly improve GS system control.
• The enhanced GS system overcomes key pharmacokinetic and dynamic barriers for therapeutic application.
• This improved gene therapy approach holds substantial promise for treating Parkinson's disease and other conditions.