On Mar 19,2025 GenAssist Ltd (GenAssist) disclosed the interim results of its base editing DMD drug, GEN6050X, from its investigator-initiated trial (IIT) (NCT06392724) at the 2025 Muscular Dystrophy Association (MDA) Clinical & Scientific Conference. The early findings indicated the encouraging therapeutic potential for this in vivo base editing drug.
As of the reporting date, the IIT study at Peking Union Medical College Hospital has dosed two DMD patients at a dose of 5×10¹³ vg/kg. The first participant (10 years old) and the second participant (6.5 years old) have completed 7-month and 5-month follow-ups, respectively.
Initial safety data from the first two participants showed favorable tolerability, with only transient and manageable serious adverse events. No hepatic toxicity and no suspected unexpected serious adverse reactions were observed. All adverse events fully resolved within the scheduled two-week inpatient period, with no subsequent clinically significant symptoms or laboratory abnormalities in the follow-up period.
Topline efficacy data from the first patient at 6 months post-treatment demonstrated clinically meaningful functional improvements: 1 point increase on the North Star Ambulatory Assessment , 3 points gain on the Performance of Upper Limb scale driven by shoulder (+1) and distal hand/wrist (+2) improvements, and more than 100 meters increase in the 6-Minute Walk Test. Cardiac function remained stable throughout follow-up.
“GEN6050X was developed on GenAssist’s RNA editing-free TAM base editing technology. GEN6050X demonstrates strong therapeutic potential in this study,” said Dr. Chunyan He, CEO of GenAssist, “Our findings have preliminarily validated the potential of gene editing as a transformative strategy for DMD, which provides patients with an alternative therapeutic option”.
The preclinical findings presented in the poster session of the conference demonstrated that GEN6050X can efficiently restore dystrophin protein and improve muscle function in DMD animal models. The GLP NHP toxicology study confirmed no severe toxicity in NHPs up to 2×1014 vg/kg, and all toxicity findings had fully resolved at 6 months. In addition, comprehensive off-target analysis showed no detectable off-target effects at DNA and RNA levels, indicating a low risk of genotoxicity.
About GEN6050X
GEN6050X is an intravenously administered base editing drug developed for DMD patients amenable to exon 50 skipping. It consists of two AAV9 vectors: one vector encoding the oTAM base editor driven by a muscle-specific promoter, while the other AAV9 vector carries 3 copies of single-guide RNA and the human ACTG1 gene, driven by another muscle-specific promoter. The action mechanism of GEN6050X includes base editor-mediated exon skipping to restore dystrophin expression and ACTG1 overexpression to enhance the cytoskeleton and improve muscle function. GEN6050X received FDA IND approval on March 6, 2025. GenAssist has a plan to initiate clinical trial globally.
For physicians interested in clinical collaboration or patients seeking to enroll in this clinical trial, please contact us: xinya@genassisttx.com.
