ANTISENSE MODULATION AND CHARACTERISATION OF MYOGENIC CELLS FROM 14 BOYS WITH DUCHENNE MUSCULAR DYSTROPHY AS PRE-TRIAL STUDY AIMED AT PATIENTS’ RECRUITMENT FOR A EUROPEAN MULTICENTRIC CLINICAL TRIAL

Dystrophin gene mutations cause Duchenne muscular dystrophy. The auspiciously approach in this very severe genetic disorder is to restore the dystrophin synthesis both in skeletal and cardiac muscle at a sufficient level to avoid or reduce the dystrophic changes and to ameliorate the consequent phenotypes. Promising results have been gained by using antisense oligoribonucleotides with different backbones, which are able to induce exon skipping in the dystrophin hnRNA therefore bypassing out-of-frame deletions. The rationale of this approach is based on the fact that the majority of DMDs is due to large deletions causing the disruption of the frame. The AONs exon skipping generates internally deleted, but functional dystrophin proteins and would convert a severe DMD into a milder Becker muscular dystrophy phenotype. A successful first-in-man trial has recently been completed on DMD and a multicentric trial is approaching. These are the reasons why, in order to make a group of Italian DMD boys eligible for being recruited in this trial, pre-trial in vitro studies have to be performed. The aim of our project is to characterise myogenic cells obtained from 14 DMD boys followed in our Centre with mutations capable of being modulated by means of exon 46 and 51 skipping. We aim at performing on patient’s cells treated with AONs, RNA and protein studies aimed at validating the efficacy of the AONs modulation. We will also validate a novel biomarker represented by an array containing the dystrophin-originated transcripts which eventual changes may help in monitoring the treatment efficacy or eventual side effects. We will also proceed to get the ISS approval for the GMP molecules to be used in the multicentric trial. These studies will therefore fully characterise AONs-treated cells of the selected Italian DMD patients making them eligible and facilitating their inclusion in the first multicentric AONs trial for dystrophinopathies.