Research Triangle Park, N.C. — October 10, 2025 — Leads & Copy — AskBio Inc., a gene therapy company wholly owned and independently operated as a subsidiary of Bayer AG, announced initial safety data from the first cohort of participants from its Phase 1/Phase 2 LION-CS101 clinical trial of investigational gene therapy AB-1003 in participants with limb-girdle muscular dystrophy (LGMD) 2I/R9.
Data from the first cohort of five participants suggested an acceptable safety profile for AB-1003, with no dose-limiting toxicities or serious adverse events reported up to 52 weeks post-treatment. Based on these data, the Data Safety Monitoring Board recommended advancing to the second cohort, announced earlier in 2025.
The presentation represents interim, blinded Cohort 1 safety data. Participants enrolled in Cohort 1 received a single intravenous infusion of AB-1003 or placebo and were followed for 52 weeks post-treatment during the main trial before entering a planned four-year long-term follow-up period. Safety assessments included adverse event monitoring, laboratory testing, physical exams, vital signs, electrocardiograms, and echocardiograms.
Commonly reported treatment-emergent adverse events were mild-to-moderate in severity and included headaches, falls, and nausea. Three participants reported asymptomatic transient transaminase elevations without changes in bilirubin levels, which returned to baseline levels after adjusting corticosteroid treatment.
The data will be presented by Chris Passalacqua, MD, Vice President of Neuromuscular Medical Affairs, AskBio, at 3:45 p.m. CEST Friday, October 10, 2025.
The LION-CS101 clinical trial is a double-blind, randomized, placebo-controlled, dose-escalation trial to evaluate the safety of AB-1003 gene therapy in adult participants (18–65 years) who have genetic confirmation of LGMD2I/R9. The trial includes two sequential, dose-level cohorts. Adult participants diagnosed with LGMD2I/R9 will receive a single intravenous infusion of AB-1003 or placebo. The trial was initiated in 2023 and will include up to 14 participants at six sites throughout the United States.
AB-1003 is an investigational recombinant adeno-associative virus (AAV)-based gene therapy that has not been approved by any regulatory authority, and its efficacy and safety have not been fully established or evaluated. It is designed to restore fukutin-related protein (FKRP) enzyme activity, primarily inside muscle cells, for the treatment of LGMD2I/R9 as a one-time intravenous (IV) infusion.
LGMD2I/R9 is a rare form of LGMD caused by mutations in the FKRP gene and is associated with weakness and wasting of arm and leg muscles. Currently, there is no approved treatment, and management is based on the signs and symptoms present in each individual.
Phil McNamara AskBio Inc. (AskBio) +1 (984) 5207211 pmcnamara@askbio.com
Source: AskBio Inc.
