Following positive results obtained in Phase I/II trial of SRP-4053 (Golodirsen), Sarepta Therapeutics has announced a plan to submit a new drug application (NDA) for accelerated approval of Golodirsen in patients with Duchenne muscular dystrophy (DMD).
According to the results of the clinical study, Golodirsen significantly boosted dystrophin protein production in 25 boys with confirmed deletions of the DMD gene amenable to exon 53 skipping. This mutation affects about 8 percent of all DMD patients.
What is Golodirsen?
Golodirsen uses exon-skipping technology and works by binding to exon 53 of the dystrophin sequence to exclude, or skip, this part of the line. This helps produce a smaller but functional form of dystrophin protein.
Positive results
Golodirsen showed the potential to treat Duchenne muscular dystrophy (DMD) in the first clinical trial of DMD patients. Press release
Why do we need to skip an exon?
DMD is caused by specific errors (mutations) in the gene that codes for dystrophin. Dystrophin is a protein that plays a crucial role in the function of muscle cells and protects them from damage as muscles contract and relaxes. These mutations in the dystrophin gene lead to a lack of dystrophin protein in muscles. Without enough dystrophin, muscles gradually grow weaker until they can’t move at all, and eventually, breathing and heart function are lost.
The condition is universally fatal, and death usually occurs before the age of 30, generally due to respiratory or cardiac failure.
More about Golodirsen
Golodirsen uses Sarepta’s proprietary phosphorodiamidate morpholino oligomer (PMO)* chemistry and exon-skipping technology to skip exon 53 of the DMD gene. Golodirsen is designed to bind to exon 53 of dystrophin pre-mRNA, resulting in exclusion, or “skipping,” of this exon during mRNA processing in patients with genetic mutations that are amenable to exon 53 skipping. Exon skipping is intended to allow for the production of an internally truncated but functional dystrophin protein.
Golodirsen is one of the investigational candidates currently being evaluated in the ESSENCE study, a global, randomized, double-blind, placebo-controlled study evaluating efficacy and safety in patients amenable to skipping exons 45 or 53.
*a phosphorodiamidate Morpholino oligomer (PMO), is a type of oligomer molecule (colloquially, an oligo) used in molecular biology to modify gene expression.
More about the clinical trial
ESSENCE: Phase III Study
Purpose: The main objective of this study is to evaluate the efficacy of SRP-4045 and SRP-4053 compared to placebo in Duchenne muscular dystrophy (DMD) patients with out-of-frame deletion mutations amenable to skipping exon 45 and exon 53, respectively.
Location: United States, Europe, Canada, Israel
For more information, please visit www.clinicaltrials.gov or www.essencetrial.com
Sources:
Portrait of Duchenne – Exon skipping and gene therapy – Blog
