Sarepta Therapeutics’ Investigational Gene Therapy SRP-9003 for the Treatment of Limb-Girdle Muscular Dystrophy Type 2E Shows Sustained Expression and Functional Improvements 2 Years After Administration

-- Protein expression in muscle was sustained for two years following treatment in the low dose cohort, with mean beta-sarcoglycan expression of 54% at 24 months, compared to 36% at Day 60, as measured by western blot --
-- Mean NSAD score improvement of 5.7 points from baseline was sustained through 24 months in low-dose cohort, and mean NSAD score improvement of 4.0 points from baseline at one year in high-dose cohort --
-- Results in both cohorts continue to reinforce the safety and tolerability profile of SRP-9003 --

CAMBRIDGE, Mass., March 18, 2021 (GLOBE NEWSWIRE) -- Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, today shared new results from the ongoing study of SRP-9003 (rAAVrh74.MHCK7.hSGCB), the Company’s investigational gene therapy for limb-girdle muscular dystrophy Type 2E (LGMD2E). In the first look at expression data from biopsies taken two years after a single administration of SRP-9003, results found sustained protein expression in muscle tissue. In functional outcomes assessments taken two years following treatment in Cohort 1 (low-dose cohort) and one year after treatment in Cohort 2 (high-dose cohort), patients continued to demonstrate stability in their NSAD (North Star Assessment for Dysferlinopathies) total score and improvements on timed function tests. Results are being presented today at the 2021 Muscular Dystrophy Association (MDA) Annual Clinical and Scientific Conference.

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 therapy construct that transduces skeletal and cardiac muscle, delivering a gene that codes for the full-length beta-SG protein, the absence of which is the sole cause of the progressive degeneration and a shortened lifespan characterized by the disease.

“This data is the first look at longer-term expression data with any gene therapy for muscular dystrophy. The meaningful and sustained levels of beta-sarcoglycan protein expression at two years and continued strength of the functional outcomes measured are tremendously positive and support continued advancement of this investigational treatment for patients,” said Louise Rodino-Klapac, Ph.D., executive vice president and chief scientific officer, Sarepta Therapeutics. “In Cohort 2, we also saw strong expression of delta-sarcoglycan and gamma-sarcoglycan proteins in addition to beta-sarcoglycan, which suggests that SRP-9003 is working to restore the dystrophin associated protein complex, or DAPC, which provides biological support for the sustained functional benefits observed in both cohorts. LGMD2E is one of the most severe forms of LGMD and causes significant disability in children while frequently leading to early mortality and the data continue to suggest this treatment could bring much needed hope to these patients.”