Researchers identify way to increase gene therapy success
October 29, 2013
Scientists in The Research Institute at Nationwide Children's Hospital have found a way to overcome one of the biggest obstacles to using viruses to deliver therapeutic genes: how to keep the immune system from neutralizing the virus before it can deliver its genetic payload. In a study published recently in Molecular Therapy, researchers found that giving subjects a treatment to temporarily rid the body of antibodies provides the virus safe passage to targeted cells, allowing it to release a corrective or replacement gene to treat disease.
Sarepta Therapeutics Introduces Online Resource Center on Exon Skipping for the Duchenne Muscular Dystrophy Community
October 02, 2013
Sarepta Therapeutics, Inc. (NASDAQ: SRPT), a developer of innovative RNA-based therapeutics, today announced a new online resource center, called Let's Skip Ahead, for families affected by Duchenne muscular dystrophy (DMD) and their healthcare providers.
Development of Multiexon Skipping Antisense Oligonucleotide Therapy for Duchenne Muscular Dystrophy
August 30, 2013
Skipping multiple exons at the same time, by using a combination of antisense oligonucleotides, offers the potential to treat a significant number of Duchenne patients. This would address one of the major limitations of current antisense therapy, in that the approach is â€œpersonalizedâ€ù and designed to skip a single exon. Specifically, exons 45 to 55 cover the main mutation â€œhotspotâ€ù of the DMD gene and this area is thought to harbor mutations that are present in more than half of Duchenne patients. Individuals with this specific 45-55 deletion show almost asymptomatic skeletal muscle involvement or exceptionally mild clinical symptoms and it is this observation that has spurred interest in developing strategies for multi-exon skipping. This review (http://www.hindawi.com/journals/bmri/2013/402369/), by leading researchers in the field of multiexon skipping, highlights novel findings from a DMD mouse model utilizing systemic multiexon skipping targeting exons 45â€“55. The authors highlight the hurdles and limitations impeding the clinical translation of this approach and provide a perspective on the opportunity for exon 45â€“55 skipping in DMD patients. Title: Development of Multiexon Skipping Antisense Oligonucleotide Therapy for Duchenne Muscular Dystrophy. Ref. BioMed Research International, Volume 2013 (2013), http://dx.doi.org/10.1155/2013/402369 Authors: Yoshitsugu Aoki, Toshifumi Yokota, and Matthew J. A. Wood
Mutation Types and Aging Differently Affect Revertant Fiber Expansion in Dystrophic Mdx and Mdx52 Mice
July 30, 2013
Skeletal muscles have been shown to display sporadic dystrophin-positive revertant fibers, both in animal models of DMD as well as in Duchenne patients. These dystrophin-positive fibers arise from spontaneous exon skipping events (alternative splicing of the mRNA) and lead to the production of an in-frame truncated dystrophin protein. The revertant events are thought to arise within a subset of muscle precursor cells which proliferate in response to the ongoing muscle degeneration and the expansion the clusters of revertant fibers is known to be dependent on active muscle regeneration. The mechanisms by which revertant fibers arise and expand are not understood, and in the present study, Toshifumi Yokoto et al. (Echigoya Y, Lee J, Rodrigues M, Nagata T, Tanihata J, et al. (2013) Mutation Types and Aging Differently Affect Revertant Fiber Expansion in Dystrophic Mdx and Mdx52 Mice. PLoS ONE 8(7): e69194. doi:10.1371/journal.pone.0069194) examined the effects of two types of mutation (mdx mice containing a nonsense mutation in exon 23 and mdx52 mice containing deletion mutation of exon 52) and aging on revertant fibers expansion and muscle regeneration. Their results demonstrate that revertant fiber expansion and muscle regeneration is influenced by both ageing and the specific type of mutation.
Threats to Validity in the Design and Conduct of Preclinical Efficacy Studies: A Systematic Review of Guidelines for In Vivo Animal Experiments
July 29, 2013
The translation of preclinical drug discover to clinical development has historically suffered a high attrition rate resulting in the majority of clinical studies failing in Phase I and Phase II clinical trials. The reasons for this are as varied and complex as the disease we aim to treat. To combat this, improvements are simultaneously needed in multiple areas; both preclinical and clinical as well as understanding the limitations of certain preclinical models as they relate to human disease. A recent paper by Kimmelman et al. (http://www.plosmedicine.org/article/fetchObject.action?uri=info%3Adoi%2F10.1371%2Fjournal.pmed.1001489&representation=PDF) examines guidelines for in vivo experiments in animals in order to help improve the fidelity of preclinical studies. The researchers identified preclinical guidelines that met their predefined eligibility criteria, and offered 55 different recommendations for the design and execution of preclinical in vivo animal studies.
Reading Frame Correction by Targeted Genome Editing Restores Dystrophin Expression in Cells From Duchenne Muscular Dystrophy Patients
June 04, 2013
A recent paper from Gersbach et al. (Molecular Therapy, 4th June, 2013) entitled â€œReading Frame Correction by Targeted Genome Editing Restores Dystrophin Expression in Cells From Duchenne Muscular Dystrophy Patientsâ€ù highlights the recent advances in approaches to correct genetic mutations in patient derived cells using an engineered nuclease.
Phase IIb Study of PRO045 in Subjects With Duchenne Muscular Dystrophy
April 09, 2013
The purpose of the study is to see whether PRO045 is safe and effective to use as medication for Duchenne Muscular Dystrophy (DMD) patients with a mutation around location 45 in the DNA for the dystrophin protein.
Review of Phase II and Phase III Clinical Trials for Duchenne Muscular Dystrophy
April 01, 2013
Evidence-based therapeutics in Duchenne muscular dystrophy (DMD) has been limited to corticosteroids for the past 30 years. There have been a host of other therapeutic interventions studied in mice, canines and more recently humans, but they are yet to show effectiveness in clinical trials. Newer genetic approaches are in early stages of clinical trials.