Parent Project Muscular Dystrophy (PPMD) announced that it has funded $59,000 to Krista Vandenborne, PhD of the University of Florida in Gainesville to test the ability of magnetic resonance imaging (MRI) to detect changes in the muscles of those living with Duchenne muscular dystrophy (Duchenne) who participated in the Sarepta phase II trial of Eteplirsen.
"This supplemental funding from PPMD allowed us to very quickly take advantage of a trial in progress to see if MRI can detect changes in the amount and quality of muscle in response to an experimental treatment," said Dr. Vandenborne.
Eteplirsen is an antisense oligonucleotide-based drug that allows skipping of exon 51 in the dystrophin gene. For approximately 13% of those with Duchenne, skipping exon 51 may lead to the production of a shorter, but functional dystrophin protein. Sarepta Therapeutics recently completed a phase II study of the drug in 12 participants and found evidence of dystrophin production and some improvement in the distance walked in six minutes.
Although the six minute walk test has been used as a primary outcome in almost all of the current clinical trials for Duchenne, study sponsors are also interested in identifying "biomarkers" or other types of measurements that might indirectly predict which study participants are responding to a therapeutic intervention. If such biomarkers can be identified and demonstrated to be linked to functional benefits, such as walking ability, they may one day be used in place of functional tests or to add supporting evidence to those tests.
Dr. Vandenborne's group has been using a technique known as "magnetic resonance imaging" or "MRI" to generate pictures of the muscles to demonstrate how much tissue is there, differentiating it from fatty scar tissue. Due to pilot data generated from an earlier End Duchenne award from PPMD, Dr. Vandenborne received a $7 million grant from the National Institutes of Health to test the ability of MRI to accurately predict the loss of muscle function in boys not undergoing treatment trials.
Now PPMD has provided an additional $59,000 to Dr. Vandenborne to test the ability of MRI to detect changes in the muscle in response to a treatment – in this case Sarepta's Eteplirsen. The investigators have collected data from the active phase of the study and will continue collecting data as the original study participants stay on the drug in the extended access program. Results of the MRI analysis from the phase II Eteplirsen study will be submitted for publication as soon as the data is compiled.
"Developing accurate, reliable ways to detect when new drugs are working has become increasingly important, as more drugs enter clinical testing for Duchenne," said PPMD's Founding President and CEO Patricia Furlong . "This study is part of our ongoing effort to provide tools that will give each new experimental drug the very best chance for success."
This grant was made possible as a result of PPMD's recent holiday campaign which focused on raising funds for projects aimed at identifying biomarkers and genetic modifiers, which will help to unlock better and faster ways of advancing clinical trials.