Sarepta Therapeutics Reports Sustained Functional Improvement Two Years After Treatment with SRP-9001, its Investigational Micro-dystrophin Gene Therapy for Duchenne Muscular Dystrophy
- Category: DNA RNA and Cells
- Published on Monday, 28 September 2020 18:14
- Hits: 1638
--Results demonstrate continued safety and tolerability of SRP-9001 in four participants with Duchenne --
--All four participants demonstrated improvements in NSAA scores compared to baseline and showed a durable response two years after administration of SRP-9001 --
CAMBRIDGE, MA, USA I September 28, 2020 I Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, today announced two-year follow up results from four Duchenne muscular dystrophy (DMD) clinical trial participants who received SRP-9001 (AAVrh74.MHCK7.micro-dystrophin). SRP-9001 is an investigational gene transfer therapy intended to deliver its micro-dystrophin-encoding gene to muscle tissue for the targeted production of micro-dystrophin protein. Results presented at the 25th International Annual Congress of the World Muscle Society demonstrated that two years after a one-time infusion of SRP-9001, trial participants exhibited a mean 7.0 point improvement on the North Star Ambulatory Assessment (NSAA) compared to baseline.
“We continue to be encouraged by the safety profile and enduring treatment response that we have seen to date with SRP-9001 gene transfer therapy,” said Doug Ingram, President and CEO, Sarepta. “The consistent results and functional improvements sustained over two years give us added confidence as we prepare for the results from Study 102, our randomized, double-blind, placebo-controlled study of SRP-9001. We continue to work with urgency to bring this potentially transformative treatment to patients as quickly as possible.”
In the open-label trial, known as Study 101, four ambulatory participants between the ages of 4 and 7 were treated with an infusion of SRP-9001 at a dose of 2x1014 vg/kg. The therapy was well-tolerated in all participants over the two-year time period. All adverse events were considered mild or moderate, and occurred within 90 days of treatment. There were no serious adverse events or evidence of complement activation.
At day 90, all participants had confirmed vector transduction and showed functional improvement on the NSAA scale and reduced creatine kinase (CK) levels. Participants demonstrated a mean increase of 5.5 points from baseline one year after treatment and 7.0 points from baseline two years after treatment. The NSAA is a validated scale developed to measure functional motor abilities in ambulant children with Duchenne, with scores ranging from 0-34.
As previously disclosed, micro-dystrophin protein levels for participants in Study 101 were as follows: 12-weeks post-infusion, a mean of 81.2% muscle fibers expressing micro-dystrophin with a mean intensity at the sarcolemma by immunohistochemistry of 96% compared to normal biopsies. Adjusted for fat and fibrotic tissue, western blot showed a mean expression of 95.8%.
SRP-9001 is an investigational gene transfer therapy intended to deliver the micro-dystrophin-encoding gene to muscle tissue for the targeted production of the micro-dystrophin protein. Sarepta is responsible for global development and manufacturing for SRP-9001 and plans to commercialize SRP-9001 in the United States. In December 2019, the Company announced a licensing agreement granting Roche the exclusive right to launch and commercialize SRP-9001 outside the United States. Sarepta has exclusive rights to the micro-dystrophin gene therapy program initially developed at the Abigail Wexner Research Institute at Nationwide Children’s Hospital.
About Duchenne Muscular Dystrophy
Duchenne muscular dystrophy (DMD) is a rare, fatal neuromuscular genetic disease that occurs in approximately one in every 3,500-5,000 males worldwide. DMD is caused by a change or mutation in the gene that encodes instructions for dystrophin. Symptoms of DMD usually appear in infants and toddlers. Affected children may experience developmental delays such as difficulty in walking, climbing stairs or standing from a sitting position. As the disease progresses, muscle weakness in the lower limbs spreads to the arms, neck and other areas. Most patients require full-time use of a wheelchair in their early teens, and then progressively lose the ability to independently perform activities of daily living such as using the restroom, bathing and feeding. Eventually, increasing difficulty in breathing due to respiratory muscle dysfunction requires ventilation support, and cardiac dysfunction can lead to heart failure. The condition is universally fatal, and patients usually succumb to the disease in their twenties.
About Sarepta Therapeutics
At Sarepta, we are leading a revolution in precision genetic medicine and every day is an opportunity to change the lives of people living with rare disease. The Company has built an impressive position in Duchenne muscular dystrophy (DMD) and in gene therapies for limb-girdle muscular dystrophies (LGMDs), mucopolysaccharidosis type IIIA, Charcot-Marie-Tooth (CMT), and other CNS-related disorders, with more than 40 programs in various stages of development. The Company’s programs and research focus span several therapeutic modalities, including RNA, gene therapy and gene editing. For more information, please visit www.sarepta.com or follow us on Twitter, LinkedIn, Instagram and Facebook.
SOURCE: Sarepta Therapeutics