Solid Biosciences has announced that the FDA has cleared its Investigational New Drug (IND) application for SGT-212, a novel gene therapy candidate for Friedreich's ataxia (FA). The therapy employs a dual route of administration to target both the neurological and cardiac aspects of the disease. A Phase 1b clinical trial is expected to begin in the second half of 2025.
SGT-212: A Dual-Action Gene Therapy
SGT-212 is an adeno-associated virus (AAV)-based gene therapy designed to deliver a full-length human frataxin (Fxn) gene. It utilizes a dual route of administration: intradentate nucleus (IDN) infusion, guided by MRI, to target the cerebellum, and intravenous (IV) infusion to reach cardiomyocytes in the heart. This approach aims to increase therapeutic Fxn levels in both the cerebellar dentate nuclei and the heart, addressing both the neurologic and systemic clinical manifestations of FA.
"SGT-212 has been intentionally designed to enable highly targeted delivery of our gene therapy to both the dentate nuclei and cardiac tissue," said Bo Cumbo, President and CEO of Solid Biosciences. "The IND was supported by a robust preclinical package demonstrating safe transduction and frataxin expression in these target tissues, with significant restoration of neurologic function and reversal of the cardiac implications of the disorder in mice."
Clinical Trial Details
The planned Phase 1b study will enroll adult patients with FA, both ambulatory and non-ambulatory, across up to three cohorts. The trial will evaluate the safety and tolerability of SGT-212 when administered systemically and bilaterally via IDN. Patients will be followed for five years after receiving the gene therapy.
Jennifer Farmer, CEO of the Friedreich's Ataxia Research Alliance (FARA), stated, "Gene therapy approaches are aimed at the underlying causes of FA, and thus important in the overall strategy to treat and cure this disease... Through our work with individuals living with FA and their families, we know they seek therapies designed to treat the debilitating neurologic symptoms that people living with FA face day-to-day, such as loss of ambulation and coordination, dysarthria, along with the life-shortening cardiac disease."
Addressing Delivery Challenges
One of the key challenges in treating FA is delivering the therapy effectively to both the brain and the heart. Solid Biosciences' approach involves direct injection into the dentate nucleus, the largest of the deep cerebellar nuclei. According to Gabriel Brooks, MD, Chief Medical Officer at Solid Biosciences, MRI-guided, convection-enhanced delivery (CED) will be used to ensure predictable and homogenous distribution of SGT-212 within the dentate nucleus.
"The gadolinium enhancement demonstrates the exact distribution of the drug, so by the end of the treatment procedure, we will know, to the minute, 'Did we deliver the drug to where it needed to go?'" said Brooks. "When we're sharing our initial safety and tolerability data, and initial cardiac transduction and expression, we will be able to say we had profound real-time imaging to provide proof that the target organ, the dentate nucleus of the cerebellum, received delivery of the drug."
Friedreich's Ataxia: An Unmet Need
Friedreich's ataxia is a debilitating, inherited disease affecting approximately 5,000 people in the United States and 15,000 in Europe. It is caused by a deficiency in the frataxin protein, leading to progressive nervous system damage, movement problems, and cardiac dysfunction. Cardiac complications are the primary cause of death in FA patients. Currently, there are no treatments that can cure or halt the progression of the disease, highlighting the urgent need for new therapeutic options.
Solid Biosciences' Pipeline
In addition to SGT-212, Solid Biosciences is developing a portfolio of gene therapy candidates for other neuromuscular and cardiac diseases, including SGT-003 for Duchenne muscular dystrophy (DMD), SGT-501 for catecholaminergic polymorphic ventricular tachycardia, SGT-601 for TNNT2-mediated dilated cardiomyopathy, and SGT-401 for BAG3-mediated dilated cardiomyopathy.
