Additional Preclinical Data Supports Clinical Advancement of First AAV-Based Gene Therapy for Adrenomyeloneuropathy
SBT101 preclinical studies demonstrate improvement in behavioral and biochemical markers of disease
Further support for dosing strategy for Phase 1/2 study initiating later in 2022
PHILADELPHIA, May 17, 2022 – SwanBio Therapeutics, a gene therapy company advancing adeno-associated virus (AAV)-based therapies for the treatment of devastating, inherited neurological conditions, is presenting additional details from studies of SBT101 in non-human primates (NHPs) and rodent models. These data support the ongoing clinical advancement of SBT101 as a potential treatment for adrenomyeloneuropathy (AMN), a progressive, inherited, and debilitating neurodegenerative disease.
The SBT101 preclinical data, presented at the American Society of Gene & Cell Therapy (ASGCT) 2022 Annual Meeting in Washington, DC, demonstrate dose-dependent functional improvement as measured by grip strength in a mouse model of AMN. Additional details from previously reported studies on efficacy, biodistribution, and safety data also support the dosing strategy SwanBio will be implementing in its upcoming Phase 1/2 study, expected to initiate by the end of the year.
“Over the past few months, we’ve been pleased to share a range of insights from our SBT101 preclinical data that have informed the design of our upcoming first-in-human study, including decisions we have made about dosing and administration,” said Karen Kozarsky, Ph.D., chief scientific officer and co-founder, SwanBio Therapeutics. “Now armed with evidence of functional improvement in an animal model, we are extremely encouraged for the potential of SBT101 to become a meaningful therapy for people living with AMN, a disease with no treatment options.”
The underlying cause of AMN is a deficiency in the ABCD1 gene, which disrupts the function of cells in the spinal cord and other tissues, leading to the accumulation of very long-chain fatty acids (VLCFAs) within affected organs, nerve degeneration and often adrenal gland dysfunction, causing the symptoms of the disease. These symptoms include loss of mobility in adulthood, incontinence, debilitating pain, and sexual dysfunction, which all negatively impact quality of life. SBT101 is designed to increase ABCD1 expression and address the root cause of the disease.
Summary of Findings
- In mouse models of AMN, intrathecal (IT) delivery of SBT101 demonstrated dose-dependent improvements in both disease markers and functional endpoints:
- Four-paw grip strength was significantly improved at 7-8 months after administration. Grip strength was maintained 10-11 months after SBT101 administration.
- VLCFA levels in the lumbar spinal cord tissue were reduced at post-mortem evaluation approximately 10-11 months after SBT101 administration.
- hABCD1 messenger RNA (mRNA) expression was detected in the lumbar, thoracic, and cervical spinal cord at post-mortem evaluation approximately 10-11 months after SBT101 administration.
- In all mouse model and NHP studies, IT administration of SBT101 was well tolerated at doses predicted to be clinically relevant in people with AMN, and no drug-associated adverse events were noted.
- In NHPs, biodistribution studies following IT delivery of SBT101 demonstrated:
- Dose-dependent presence of AAV9 vector genomes and hABCD1 mRNA in target (CNS) tissues
- Extended administration (a 24-hour infusion time) of AAV9 provided more widespread transduction of AMN target tissues (spinal cord and dorsal root ganglia) as compared to bolus administration
- A six-hour administration was shown to be equivalent to the extended infusion time in terms of delivering widespread distribution of AAV9 vector to AMN target tissues
Abstract #57: Selection of Clinical Doses for SBT101, an AAV9-hABCD1 Vector for the Treatment of Adrenomyeloneuropathy
Session: Oral Presentation – “AAV Preclinical CNS Gene Therapy” Room 204
Date & Time: May 16, 2022, 3:45-4:00 pm ET
Abstract #162 / Poster Board #M-43: Preclinical Pharmacology and Toxicology of Intrathecally Infused AAV9-hABCD1 (SBT101), a Gene Therapy Candidate for AMN, in Non-Human Primates
Session: Poster Presentation – “AAV Vectors – Preclinical and Proof-concept Studies I” Hall D
Date & Time: May 16, 2022, 5:30-6:30 pm ET
Abstract #529 / Poster Board #Tu-34: An AAV9-Encoding Human ABCD1 Shows Functional Improvement Following Spinal Cord Delivery in a Rodent Model of AMN
Session: Poster Presentation – “AAV Vectors – Preclinical and Proof-concept Studies II” Hall D
Date & Time: May 17, 2022 5:30-6:30 pm ET
Abstract #922 / Poster Board #W-48: Optimization of Intrathecal Delivery of an Infused AAV9 Vector for Delivery of a Gene Therapy Candidate for AMN in Non-Human Primates
Session: Poster Presentation – “AAV Vectors – Preclinical and Proof-concept Studies III” Hall D
Date & Time: May 18, 2022, 5:30-6:30 pm ET
SBT101 is the first AAV-based gene therapy candidate cleared by the FDA for human studies, designed to compensate for the disease-causing ABCD1 mutation in people living with adrenomyeloneuropathy (AMN). In preclinical studies, treatment with SBT101 demonstrated dose-dependent improvement of disease markers and functional improvement in AMN mouse models. SBT101 was also shown to be well-tolerated in non-human primates at six months post-treatment. The clinical program for SBT101 builds on this positive preclinical data, plus the company’s deep understanding of the underlying pathophysiology of the disease and the patient experience of AMN, including new insights being gathered in an ongoing, proprietary natural history study, CYGNET.
SwanBio expects to initiate a randomized, controlled Phase 1/2 clinical trial designed to assess the safety and efficacy of SBT101 in patients with AMN in the second half of 2022. In early 2022, the FDA cleared SwanBio’s Investigational New Drug application for SBT101 and granted SBT101 Fast Track and Orphan Drug Designation.
Adrenomyeloneuropathy (AMN) is a progressive and debilitating neurodegenerative disease caused by mutations in the ABCD1 gene that disrupt the function of spinal cord cells and other tissues. AMN is characterized by loss of mobility in adulthood, incontinence, pain, and sexual dysfunction which all affect quality of life. Between 8,000-10,000 men in the United States and European Union are living with AMN. There are no approved therapies for the treatment of the disease; current standard of care is limited to symptom management.
About SwanBio Therapeutics
SwanBio Therapeutics is a gene therapy company that aims to bring life-changing treatments to people with devastating, inherited neurological conditions. SwanBio is advancing a pipeline of gene therapies, designed to be delivered intrathecally, that can address targets within both the central and peripheral nervous systems. This approach has the potential to be applied broadly across three disease classifications – spastic paraplegias, monogenic neuropathies, and polygenic neuropathies. SwanBio’s lead program is being advanced toward clinical development for the treatment of adrenomyeloneuropathy (AMN). SwanBio is supported by long-term, committed investment partners, including its primary investors Syncona Limited (lead investor and majority shareholder) and Mass General Brigham Ventures. For more information, visit SwanBioTx.com.
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