GEMMABio Announces Clinical Trial Authorization for New SMA1 Gene Therapy

Program deemed safe-to-proceed in Brazil with the first dosing expected within the next few months

PHILADELPHIA, Nov. 24, 2025 /PRNewswire/ -- Gemma Biotherapeutics ("GEMMABio"), a leading global genetic medicines company, announced that its novel gene therapy for spinal muscular atrophy type 1 (SMA1) is cleared for clinical trial by ANVISA, the health regulatory agency in Brazil. The promising preclinical data from GEMMABio's first clinical-stage program was presented by the company's President and CEO, James M. Wilson, MD, PhD, at the INAME 2025 Spinal Muscular Atrophy Congress which took place on November 21-23, 2025, in São Paulo, Brazil.

In a talk entitled "Gene Therapy for SMA1: History, R&D on Next Generation Therapy, and the Challenge of Affordability," Dr. Wilson described his team's approach to creating GB221, a next-gen therapy for SMA1. GB221 is a one-time gene therapy that consists of an adeno-associated virus (AAV) human isolate, AAVhu68, encasing a functional copy of a codon-optimized SMN1 gene in a modified transgene cassette designed to reduce motor and sensory neurotoxicity. It is delivered directly to the cerebrospinal fluid (CSF) via intra-cisterna magna (ICM) injection.

In preclinical studies, GB221 improved survival and neuromotor function in a mouse model of SMA1. Furthermore, the investigational new therapy demonstrated high levels of motor neuron transduction without toxicity in non-human primates (NHPs). In addition, off-target delivery to the liver was substantially reduced in NHP preclinical studies.

"We look forward to opening SMA1 clinical trial sites in Brazil and moving this program into the clinic," said GEMMABio CEO Dr. Jim Wilson, who also serves as a Member of the International Expert Advisory Board at Brazil's Casa dos Raros ("House of Rare"). "SMA1 is a devastating motor neuron disease with high unmet need, as existing disease-modifying therapies are expensive and the cost sharply restricts access to care. Without treatment, patients will not survive to their second birthday."

The proprietary central nervous system (CNS) platform technology, developed by Dr. Wilson's research team and licensed from the University of Pennsylvania, showed a reassuring preclinical safety profile and durable expression in NHP studies. Notably, in research animals, the direct CNS delivery via ICM injection allows lower vector doses to be used without compromising therapeutic gene expression in the target tissues. In preclinical studies, this strategy mitigates systemic toxicity related to higher vector doses observed in other intravenously administered gene therapies. In addition, the lower doses used by ICM delivery are anticipated to reduce the cost of goods sold (COGS), enhancing the affordability of this novel treatment and expanding access to patients.

The SMA1 clinical activities are a core element in the partnership agreement between GEMMABio and the Oswaldo Cruz Foundation (Fiocruz) which was announced in October 2024. Over the past year, ANVISA, the Brazil Ministry of Health, Fiocruz, and Intrials (a clinical research organization based in Brazil which will help manage the clinical trials), worked closely with GEMMABio to ensure SMA1 program readiness. The publicly funded healthcare system in Brazil, Sistema Único de Saúde (SUS), is the largest in the world and serves 200 million people.

Under the partnership agreement, GEMMABio is also transferring vector production technology to the Institute of Technology on Immunobiologicals (Bio-Manguinhos) at Fiocruz. This unique component of the relationship aligns with the Brazil Ministry of Health's current directive to strengthen the health and economic industrial complex of the country. According to Mario Moreira, PhD, MPH, Fiocruz President, this collaboration will bring new technology to Brazil, reduce costs, and increase access to these therapies in the national healthcare system.

"Historically, SMA1 patients in Latin America experienced an inconsistent standard of care due to variability in access to medical treatment," said Jonas Morales Saute, MD, PhD, who specializes in neurology and neurogenetics at the Hospital de Clínicas de Porto Alegre in Brazil and who was tapped to be a principal investigator on the clinical trial. "A more affordable, one-time treatment option distributed through research and treatment centers (RTCs) in Brazil has the potential to revolutionize SMA1 patient care in LATAM in a very short period of time."

The company anticipates opening three clinical sites in Brazil and dosing the first patient there within the next few months. Brazil will serve as a regional hub in Latin America for GEMMABio's gene therapy programs.

In addition to Brazil, GEMMABio has a key international relationship with Abu Dhabi which will serve as a regional center for gene therapy in the Middle East. The SMA1 clinical trial will be open in both regions, with the Middle East clinical site anticipated to initiate later in 2026.

For information on the clinical trial design for GB221, please visit ClinicalTrials.gov. Please note that enrollment is not yet open for the clinical trial.

About SMA1
Spinal muscular atrophy (SMA) is a progressive neurodegenerative disease that affects motor neurons in the spinal cord and adversely affects the skeletal muscles. Progressive muscle weakness impairs breathing, eating, crawling/walking, and other activities. SMA is caused by a mutation in the survival motor neuron gene 1 (SMN1), and it follows an autosomal recessive pattern of inheritance. The global incidence of all types of SMA, whose severity is modulated by the number of SMN2 gene copies, is approximately 1:10,000 live births.

SMA Type 1 (SMA1) is a very severe form with early onset and diagnosis occurring at less than 6 months of age. Untreated SMA1 patients do not survive beyond 18 months of age. SMA1 patients typically have 1-2 copies of the SMN2 gene. The global incidence of SMA1 is approximately 1:17,000 live births.

About GEMMABio
GEMMABio is a therapeutics company focused on speeding the research of and global access to life-changing advanced therapies for those living with rare diseases. The company conducts research and product development functions to bring gene therapy discoveries from the bench to the bedside faster and affordably. GEMMABio is led by gene therapy industry pioneer Jim Wilson and his team of experts, who previously conducted their work in academia. Learn more about GEMMABio at gemmabiotx.com and follow us on LinkedIn.

University of Pennsylvania Financial Disclosure
The University of Pennsylvania ("Penn") owns an equity interest in GEMMABio. Penn has either received, or may receive in the future, financial consideration related to the licensing of certain Penn intellectual property to GEMMABio.

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SOURCE GEMMA Biotherapeutics