AVI BioPharma, MDA to initiate exon-51 Phase 2 trial in Duchenne muscular dystrophy

More than a decade of targeted Muscular Dystrophy Association-funded research, made possible as a result of generous public support of the MDA Labor Day Telethon and thousands of grass-roots special events, has today culminated in MDA providing financial assistance for the start of the first Phase 2 placebo-controlled, multiple dose efficacy, safety, tolerability and pharmacokinetics clinical trial of an exon-51 skipping drug, eteplirsen, as a potential therapy for Duchenne muscular dystrophy (DMD).

The first three of 12 DMD boys participating in the AVI BioPharma clinical trial at Nationwide Children's Hospital in Columbus, Ohio today received the first of 24 weekly doses of eteplirsen or a placebo by intravenous infusion (i.v.).  Four more participants had muscle biopsies vital to measuring the presence of the essential muscle protein dystrophin both before and after treatments.  The seven boys traveling in for the study launch are from Calif., Ill., Fla., Wis., Va. and Mo.

"This is an important day for families fighting muscular dystrophy," said R. Rodney Howell, M.D., Chairman of the MDA Board of Directors. "AVI BioPharma already completed a 19-patient clinical trial in the United Kingdom confirming the potential of eteplirsen to be a safe and effective disease-modifying drug for DMD (The Lancet, July 25, 2011).  Now, a team led by Dr. Jerry Mendell is receiving funding from MDA to help initiate this randomized, double-blind, placebo-controlled 12-patient trial needed to further test safety, efficacy and optimal dosing."

"Twenty-five years ago, MDA-funded investigators identified the dystrophin gene that, when mutated (or defective) causes Duchenne muscular dystrophy as well as the somewhat milder Becker muscular dystrophy (BMD)," explained Mendell, Curran-Peters Chair of Pediatric Research at Nationwide Children's Hospital, and Professor of Pediatrics and Neurology at Ohio State University. "Today, we're underway with a clinical trial of a drug that ultimately could create a shortened but functional dystrophin protein for DMD boys with certain out-of-frame gene deletions that may be corrected by skipping exon 51."

"By administering eteplirsen by i.v. for 24 weeks," Mendell added, "our goal is to find the best dosage to trick the body into skipping over genetic disruptions present in some cases of DMD, to produce dystrophin levels typical of Becker muscular dystrophy.  In Becker many patients are able to walk into late adulthood and to have normal or near normal life spans."

The introduction of exon skipping to restore the open reading frame using splice-switching oligomers targeting dystrophin exons is one of several attractive therapeutic strategies for Duchenne muscular dystrophy being pioneered by MDA-funded investigators.  

"MDA has been funding exon skipping research for Duchenne muscular dystrophy for more than a decade," noted Valerie Cwik, M.D., MDA Executive Vice President – Research and Medical Director.  "We're very pleased to now be collaborating with AVI BioPharma on this trial and are hopeful that eteplirsen will become an effective therapy for those living with Duchenne muscular dystrophy."