GEMMA Biotherapeutics Secures $34M Seed Funding and Advances Three AAV Gene Therapies for Pediatric Rare Diseases into Clinical Development

Rare diseases are one of the greatest challenges facing human medicine.

Among the wide variety of rare diseases, approximately 80% are caused by genetic defects and are hereditary. In recent years, gene therapy has achieved improved therapeutic outcomes by promoting normal gene expression in the human body through innovative approaches such as gene replacement and gene editing.

GEMMA Biotherapeutics (hereinafter referred to as “GEMMABio”) is a gene therapy company dedicated to developing treatments for rare diseases, committed to bringing hope to more patients with rare conditions.

Previously, GEMMABio announced the completion of a $34 million (approximately RMB 250 million) seed funding round. The round was co-led by Double Point Ventures, Bioluminescence Ventures, and Earlybird Venture Capital, with additional support from Savanne Life Sciences. The funds will drive GEMMABio’s operational expansion and innovative gene therapy programs.

To date, the team led by its founder, James M. Wilson, has achieved numerous notable milestones: three FDA-approved AAV-based gene therapies, more than 40 development projects, 95 patents related to gene therapy technologies, and first-in-human studies for 15 different diseases.

(Founder Dr. James M. Wilson, image source: GEMMABio official website)

Dr. James Wilson is the President and Chief Executive Officer of GEMMABio, with nearly 40 years of experience in the field of gene therapy.

In 1993, Dr. Wilson established the first academic gene therapy program at the University of Pennsylvania and successfully identified adeno-associated virus (AAV) in 2004, laying the foundation for subsequent advances in gene therapy. Furthermore, Dr. Wilson has actively promoted the commercial development of these novel gene therapy platforms and founded eight biotechnology companies.

Passage Bio is one such company. Headquartered in Philadelphia, Pennsylvania, it conducts research and collaborates with the University of Pennsylvania and its Gene Therapy Program (UPenn-GTP), holding certain patent license agreements. Passage Bio is responsible for the clinical development, regulatory filings, regulatory affairs, and commercialization activities of gene therapy products under these agreements. UPenn-GTP focuses on the development of gene therapies and drives preclinical work, including Investigational New Drug (IND) applications. The close partnership between the two entities accelerates the translation of gene therapy innovations into clinical applications.

Dr. May Orfali is the Chief Medical Officer of GEMMABio, with over 30 years of experience in clinical development and medical affairs across oncology, infectious diseases, and rare and orphan diseases. Prior to joining GEMMABio, Dr. Orfali served as Executive Vice President and Chief Medical Officer at Sigilon Therapeutics, a biopharmaceutical company focused on acute and chronic diseases that was acquired by Eli Lilly in 2023.

Leveraging its team’s extensive industry experience, GEMMABio has garnered favor from numerous overseas investors. In October 2024, GEMMABio entered into a partnership with the Fiocruz Foundation, a public health research institution under the Brazilian Ministry of Health, securing $100 million in funding to support its clinical research and manufacturing operations. The collaboration aims to reduce the cost of treating rare diseases and make therapies accessible to patients at prices affordable for Brazil’s public healthcare system.

It is reported that three pediatric lysosomal storage disorder projects in clinical development have been licensed to GEMMABio, including PBGM01 for the treatment of GM1 gangliosidosis, PBKR03 for the treatment of Krabbe disease, and PBML04 for the treatment of metachromatic leukodystrophy.

Will Chou, President and CEO of Passage Bio, stated that licensing multiple pediatric product lines to GEMMABio will enable the company to focus more intently on the research and development of PBFT02 for adult neurodegenerative diseases.

It is worth noting that although the aforementioned products target different rare diseases, they share a common feature: all are AAV gene therapies focused on rare diseases in infants and young children.

Adeno-associated virus (AAV) is a class of vectors that play roles in encapsulation, protection, and delivery in clinical gene therapy. Among all vectors, adeno-associated virus (AAV) is considered an ideal class of gene therapy vectors, offering advantages such as high safety, strong targeting capability, and excellent stability. After the therapeutic genes carried by AAV vectors enter cells, they can be transcribed and translated into functional proteins, thereby achieving therapeutic objectives.

The first product, PBGM01, is indicated for the treatment of GM1 gangliosidosis. GM1 gangliosidosis is a rare and life-threatening disorder of the central nervous system. Its mechanism of action involves cisterna magna injection to deliver a functional GLB1 gene encoding β-galactosidase (β-Gal) to the brain and peripheral tissues, leveraging the AAVhu68 viral capsid. This approach increases β-Gal activity, reduces the accumulation of toxic GM1 gangliosides, reverses neuronal toxicity, and thereby restores patients’ developmental potential.

Existing clinical trial data have demonstrated that PBGM01 has a favorable safety profile.According to the trial data disclosed on Passage Bio’s official website, no treatment-related serious adverse events (SAEs) were observed during the 3- to 20-month follow-up period. All treatment-related adverse events (AEs) were mild to moderate in severity, indicating an overall favorable safety profile.

The second product, PBKR03, is indicated for the treatment of Krabbe disease. Krabbe disease is a rare inherited lysosomal storage disorder in children caused by mutations in the galactocerebrosidase (GALC) gene. The life expectancy for infants with the most severe form of Krabbe disease is only two years.

PBKR03 utilizes a proprietary AAV capsid and is administered via intracisternal magna (ICM) injection to deliver the GALC gene into the cerebrospinal fluid. In March 2022, Passage Bio initiated the Phase I/II clinical trial of PBKR03, known as GALax-C.

The third product, PBML04, is indicated for the treatment of metachromatic leukodystrophy (MLD) and received Investigational New Drug (IND) clearance from the U.S. FDA in June 2022.

Metachromatic leukodystrophy (MLD) is a rare, fatal genetic disorder that causes sulfatides to accumulate in the brain and other parts of the body, leading to neurological damage and developmental regression. In the most severe cases, infants develop normally at first but later rapidly lose the ability to walk, speak, and interact with their surroundings. These children may eventually deteriorate into a vegetative state, requiring 24-hour intensive care.

In the United States, metachromatic leukodystrophy (MLD) affects approximately 1 in 100,000 live births. Among patients with the late-infantile and early-juvenile forms, the mortality rate is 50% within five years of onset and 44% within ten years. There is currently no effective cure for MLD; treatment primarily focuses on supportive care and symptom management.

This licensing agreement will help accelerate the clinical development and commercialization of three products, enabling Passage Bio’s gene therapies to reach patients more quickly.

Gene therapy fills the gap in treatment options for refractory diseases, offering novel therapeutic concepts and approaches for intractable conditions such as genetic disorders and cancer, and has become one of the most competitive arenas in the global innovative drug sector.

The global gene therapy market is showing significant growth. According to BCC Research, the global cell and gene therapy market is projected to grow from $7.2 billion in 2023 to $23.3 billion by the end of 2028, representing a compound annual growth rate (CAGR) of 26.4% during the forecast period from 2023 to 2028.

Driven by broad market prospects and patient demand, the number of companies in China laying out strategies in novel cell and gene therapies has increased. Particularly in the field of gene drug development based on adeno-associated virus (AAV) vectors, multiple Chinese biotech firms have entered this arena. In terms of indications, approved and investigational gene therapy drugs currently cover areas such as ophthalmic diseases, hematologic disorders, genetic diseases, and rare diseases. Just this year, AAV gene therapy products from companies such as Belief Therapeutics, Huayi Lejian, and Jinlan Genes have made significant progress.

It is reported that on April 10, Betta Pharmaceuticals’ Boperdaco base injection was approved for market launch in China for the treatment of adult patients with moderate to severe hemophilia B (congenital factor IX deficiency). This marks the first recombinant adeno-associated virus (AAV) gene therapy approved in China for hemophilia B, filling a gap in the domestic gene therapy market for this condition.

On April 22, the first patient in China was successfully dosed with Huayi Lejian’s GS1191-0445 injection in the Phase III clinical trial at the Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences. This marks the official launch of the Phase III clinical study of this drug, representing a critical milestone for the project.

In May, GEMMABio successfully held the kick-off meeting for the primary center of the pivotal Phase III clinical trial of GC101, an adeno-associated virus (AAV) injection for the treatment of type 2 spinal muscular atrophy (SMA), at the Seventh Medical Center of the Chinese PLA General Hospital. This marks the entry of GC101 injection into the pivotal Phase III stage of clinical research.

AAV vectors have emerged as the most widely used gene delivery tools in the field of gene therapy, owing to their significant advantages such as high transduction efficiency, strong tissue and cell targeting capabilities, and low immunogenicity. However, it is also important to recognize that alongside the rapid development of China’s gene therapy industry, critical issues regarding the efficacy, safety, payment mechanisms, and indication landscape of gene therapies remain urgent challenges to address. In the future, with continuous optimization of delivery technologies, AAV-based gene therapies are expected to achieve breakthroughs in a broader range of indications.

Reference Article:

1.  https://www.passagebio.com/our-science/our-approach/default.aspx 

2.  https://www.gemmabiotx.com/

3. Feng Xuejiao, Heng Chao, Yu Xinyu, Wang Junshu: “Market Analysis and Prospects of the Gene Therapy Industry,” Chinese Journal of Biotechnology, Vol. 43, No. 6, 2023.

4. Leaf, “China’s First AAV Gene Therapy Approved for Market Launch: How to Break Through the AAV Scale-up Bottleneck from Plasmid to Transfection,” YiMaiKe, April 15, 2025.