Inside The FOXG1 Gene Therapy Program

We’re developing the groundbreaking FOXG1 AAV9 gene replacement therapy—the first-ever treatment designed for FOXG1 syndrome.

Learn everything about this historic parent-led program and how you can help us reach our $22 million goal to bring this gene therapy to children worldwide.

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What is the FOXG1 Gene Therapy?

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Gene therapy is a cutting-edge approach that targets the root cause of genetic disorders by replacing or correcting a faulty gene.

In FOXG1 syndrome, a single gene mutation disrupts brain development and function. Our gene replacement therapy aims to restore healthy FOXG1 expression by delivering a working copy of the gene directly to brain cells.

To do this, we use an AAV9 viral vector—a trusted and widely used delivery system for gene therapy in the brain. Think of the vector as a boat, carrying the healthy FOXG1 gene (the passenger) to the cells that need it. Once delivered, the goal is to replace the loss of FOXG1 protein caused by the mutation, helping the cells function more normally.

Why Is Gene Therapy So Promising?

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Gene therapy has transformed what once seemed impossible into reality: the ability to treat, and in some cases reverse, devastating genetic diseases with a single treatment. In spinal muscular atrophy (SMA)—a disease that was once universally fatal in infants—gene therapy (Zolgensma®) has enabled babies to sit, stand, and even walk. In Leber congenital amaurosis, a form of inherited blindness, gene therapy (Luxturna®) has restored vision in children. And in metachromatic leukodystrophy (MLD), gene therapy has halted disease progression and preserved neurological function in young patients who would otherwise have faced severe decline.

While every disorder is unique, these breakthroughs show the extraordinary potential of gene therapy to change lives—not just manage symptoms, but rewrite the course of disease.

Why Gene Therapy is a Promising Approach for FOXG1 Syndrome

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FOXG1 syndrome is caused by a mutation in just one copy of the FOXG1 gene. That means the body still has one working copy—it simply needs more of the correct FOXG1 protein. Gene therapy is uniquely suited to this type of disorder because it can deliver a working copy of the gene directly to the brain, increasing FOXG1 protein levels and potentially improving key neurological functions. Current scientific data and preclinical models give us real reason to believe that gene therapy can make a meaningful difference in the lives of children with FOXG1. That’s why we’re moving urgently—and carefully—toward and through clinical trials.

Our preclinical data shows that this technique works using various types of AAV vectors (boats) in animal models of FOXG1 syndrome, where we observe treatment-induced increase in expression of FOXG1 in animals’ brains and correspondingly we observe improvement in symptoms in the animals models, which recapitulate some of the symptoms characteristic of human FOXG1 syndrome patients. We found groundbreaking results showing restoration of the brain structural abnormalities (agenesis of the corpus callosum).

FOXG1 Gene Therapy Team

Gai Ayalon, Ph.D.

Chief Drug Development Officer

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Dr. Gai Ayalon, Ph.D., is a neuroscientist with a passion for bringing treatments to children with ultra-rare diseases. As Chief Drug Development Officer, Dr. Ayalon is leading the FOXG1 Research Foundation’s gene therapy program through clinical development. He has built and leads the Foundation’s core gene therapy team, which includes Charles River Laboratories and other key partners advancing the program toward clinical trials.

Previously, Dr. Ayalon led clinical development programs for pediatric neurodevelopmental disorders at Ultragenyx Pharmaceutical, where he also launched and piloted clinical readiness teams to accelerate the transition from preclinical research to human trials.

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IQVIA FOXG1 Partnership
  • Close-up of a woman with short dark hair smiling in front of a brick wall.

    Elli Brimble

    FRF Chief Clinical Data Officer

  • A woman with long, wavy reddish-brown hair smiling at the camera, wearing a black top and blazer, in a bright, modern indoor setting.

    Mallory Lauth, MS

    Founder & CEO, Lauth Life Sciences | Program Management & Clinical Operations Consulting

  • A woman with short dark hair and glasses, wearing a blue top and a blue scarf, standing indoors.

    Lauren E. Black PhD

    Scientific Advisory, Preclinical Strategy, Charles River Laboratories

  • A smiling woman with short blonde curly hair wearing a navy blazer and a pearl necklace.

    Carol Zoltowski, VMD

    Principal of CZ Associates, LLC | Regulatory Affairs & Quality Consulting

Clinical Trial FAQ

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As the FOXG1 Research Foundation advances toward clinical trials for our FOXG1 gene replacement therapy, naturally, parents and caregivers have many questions. This page will be updated regularly to serve as a communication touch-point to answer Frequently Asked Questions.

View Clinical Trial FAQ

FOXG1 Gene Therapy Roadmap

FOXG1 Gene Therapy Roadmap

Help Us Drive the FOXG1 Gene Therapy Through Patient Trials—Starting in 2026.

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Our “Yes, They Can!” FOXG1 Gene Therapy campaign is raising $22 million to independently fund this life-changing treatment through full-scale, multi-site patient trials.

Support the "Yes, They Can!" Campaign

Watch Dr. Gai Ayalon discuss the FOXG1 gene therapy

At the 2024 FOXG1 Syndrome Parents Conference in Florida, Dr. Gai Ayalon presented on the roadmap to deliver the FOXG1 gene therapy to patients around the world. Watch Gai’s presentation here.