On the morning of May 14, US Eastern Time, at the 29th Annual Meeting of the American Society of Gene & Cell Therapy (ASGCT), Byongen Therapeutics delivered an oral presentation, disclosing for the first time the core achievements of a novel muscle-targeting AAV capsid discovered via in vivo screening in non-human primates (NHPs). This breakthrough technology serves as the core vector support for the joint development of a next-generation Duchenne Muscular Dystrophy (DMD) gene therapy by Genecradle Therapeutics and Byongen Therapeutics.

Title: Directed Evolution in Nonhuman Primates Identifies AAV Capsids with a Novel Motif Enabling Efficient Muscle Targeting with Reduced Liver Tropism Authors: Gang Wang, Ying Ba, Qingyu Deng, Yan Zhao, Ruxue Chen, Yangyang Zhong Affiliation: Byongen Therapeutics, Beijing, China Venue & Date: Boston, Massachusetts, May 14, 2026

Since the strategic cooperation was established in February 2025, the two parties have carried out R&D collaboration with complementary strengths. Byongen Therapeutics has developed a new generation of highly efficient AAV delivery capsids, while Genecradle Therapeutics has independently developed Smart-Dystrophin, the original core therapeutic element. By combining advanced vectors with self-developed therapeutic cores, the two parties jointly advance the development of DMD gene therapy solutions. The capsid research results released at this conference lay an important foundation for the follow-up joint R&D and implementation of the two parties.

The key pain point of DMD gene therapy lies in the low muscle transduction efficiency and high off-target liver toxicity of traditional AAV vectors, which require high-dose administration and carry safety risks. The novel muscle-targeting motif disclosed by Byongen Therapeutics achieves potent delivery to systemic skeletal muscle in NHP models while greatly reducing non-specific liver expression, combining excellent efficacy and safety. The NHP data are highly consistent with human physiology, indicating great clinical translation potential.

If the optimized novel capsid is the "precision navigation" for targeted delivery, then Genecradle Therapeutics’ original Smart-Dystrophin is the "core engine" that determines the efficacy of gene therapy. Different from the widely adopted mini/micro-dystrophin truncation strategy in the industry, Genecradle, on the premise of fully adapting to the packaging capacity limit of AAV vectors, has systematically optimized and retained key functional domains through in-depth analysis of the structure and function of natural dystrophin. This enables Smart-Dystrophin to maintain more comprehensive biological activity and be closer to the physiological function of the natural protein even under the constraint of molecular size. At present, Smart-Dystrophin has completed systematic validation in a variety of DMD preclinical animal models, accurately anchors to the muscle cell membrane, and significantly improves muscle strength and motor capacity at the functional level.

In terms of transcriptional regulation, Genecradle has simultaneously developed a muscle-specific promoter with independent intellectual property rights. In the current DMD gene therapy field, including some investigational pipelines, synthetic promoters such as SPC5-12 are commonly used to drive transgene expression. The drive strength of the novel muscle promoter is significantly higher than that of SPC5-12 used in RGX-202 (with an average increase of more than 10 times), which can further amplify the expression level of therapeutic proteins and enhance the overall efficacy.

With stronger expression drive capacity, Genecradle’s gene therapy strategy not only focuses on changes in biomarkers such as reduced creatine kinase (CK) levels, but also takes the tangible improvement of patients’ motor function and quality of life as its core goal, striving to bring clinically meaningful functional benefits to DMD patients.

This cooperation is not a simple superposition of capabilities, but an organic integration of two core technical systems: Genecradle Therapeutics’ profound accumulation in therapeutic gene design, drug R&D and clinical translation, and Byongen Therapeutics’ cutting-edge capabilities in AAV capsid engineering and directed evolution technology are closely integrated and synergized, forming a complete closed technical loop of "high-performance delivery capsid + optimized therapeutic core".

As an indication with high dosage demand in the field of AAV gene therapy, the large-scale treatment of DMD imposes higher requirements on the manufacturing of AAV gene drugs. Efficient and low-cost large-scale production is the key to ensuring the accessibility of DMD gene therapy. Relying on its profound accumulation in the manufacturing of AAV gene drugs, Genecradle Therapeutics has built an efficient large-scale production system to meet the dosage demand of DMD treatment. By optimizing production processes and improving production efficiency, it helps control drug costs and provides solid Chemistry, Manufacturing and Controls (CMC) support for the wide implementation of DMD gene therapy.

In the future, Genecradle Therapeutics will continue to work with Byongen Therapeutics to accelerate the preclinical research and clinical trial process of the next-generation DMD gene therapy, and strive to bring this breakthrough treatment to DMD patients worldwide as soon as possible. Meanwhile, taking the R&D cooperation of DMD therapy as an opportunity, Genecradle Therapeutics will further improve the full-chain layout of AAV gene drugs from technology R&D, clinical translation to large-scale production, continuously strengthen core CMC capabilities, and lay a solid foundation for the implementation of various AAV gene therapy drugs.