Sarepta Therapeutics Announces Positive Expression and Functional Data From the SRP-9003 Gene Therapy Trial to Treat Limb-Girdle Muscular Dystrophy Type 2E

-- In post-treatment muscle biopsies, clinical trial participants in the high-dose cohort showed a dose-dependent increase in transduction and expression when compared with the low-dose cohort, with a mean of 72% beta-sarcoglycan (beta-SG) positive fibers, as measured by immunohistochemistry (IHC), substantially exceeding the pre-defined 50% measure for success -- 
-- A mean signal intensity of 73% in the high-dose group was observed compared to normal control --
-- A mean beta-sarcoglycan expression of 62% as measured by Western blot was observed in the high-dose cohort compared to normal control --
-- An 89% mean reduction of creatine kinase (CK) from baseline was observed in the high-dose cohort --
-- Continued functional improvement was observed in the low-dose cohort at one year --

CAMBRIDGE, Mass., June 08, 2020 (GLOBE NEWSWIRE) -- Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, today announced positive results from a study of SRP-9003,  its investigational gene therapy for limb-girdle muscular dystrophy Type 2E (LGMD2E). Results included safety and expression results from three clinical trial participants in the high-dose cohort measured at 60 days, and one-year functional data from three clinical trial participants in the low-dose cohort. SRP-9003 is in development for the treatment of LGMD2E (also known as beta-sarcoglycanopathy and LGMDR4), a devastating monogenic neuromuscular disease caused by a lack of beta-sarcoglycan (beta-SG) proteins. SRP-9003 is a gene construct that transduces skeletal and cardiac muscle, delivering a gene that codes for the full-length beta-sarcoglycan protein, the absence of which is the sole cause of progressive degeneration and a shortened lifespan characterized by the disease.  

“We were very encouraged by the previously reported results from our first cohort of patients treated with a lower dose of SRP-9003, including impressive expression, good tolerability, and positive functional signals, which continue impressively at one year.  We are excited to have been able to achieve even more impressive expression and other biomarkers in our higher-dose cohort for SRP-9003, along with good tolerability. The SRP-9003 gene construct, vector and promoter were designed with the goal of robustly delivering to skeletal and cardiac muscles a gene coding for the missing beta-sarcoglycan protein that causes LGMD2E. These data support the conclusion that the therapy is achieving its intended purpose, driving robust expression in the muscles where it is needed,” said Doug Ingram, President and CEO, Sarepta. “SRP-9003 employs the same vector, AAVrh74, and same promoter, MHCK7, as SRP-9001, our therapy in development to treat Duchenne muscular dystrophy. And Cohort 2 received a similar dose as our ongoing SRP-9001 studies for Duchenne.  The safety and efficacy results with these two doses of SRP-9003 provide us with additional experience and confidence with the rh74 vector and the MHCK7 promoter as we select the dose for the pivotal trial of SRP-9003 and work to quickly develop this therapy for patients who currently have no treatment options.”