Longitudinal multicentric study to validate SV95C in ambulant DMD aged 2-15 years old

Topic:

Clinical Trials

Poster Number: M169

Author(s):

Laurent Servais, MD, PhD, University of Oxford, Guillaume Parinello, MSc, SYSNAV, Vernon, France, Margaux Poleur, MD, CRMN, University department of neurology, Citadelle Hospital of Liege, Belgium, Eva Vrscaj, MD, University Children's Hospital, Ljubljana, Slovenia, Marketa Kumhera, MD, Motol University Hospital, Prague, Czech Republic, Celine Cluzeau, PhD, SYSNAV, Vernon, France, Karolina Aragon-Gawinska, MD, Department of Neurology, Medical University of Warsaw, Warsaw, Poland, Cristina Anghelescu, MD, Department of Paediatric Neurology, Alexandru Obregia Clinical Hospital, Bucharest, Romania, Mihaela Axente, MD, University of Medicine and Pharmacy Carol Davila, Bucharest, Romania, Aurore Daron, MD, University department of neurology, CHR Citadelle, Liege, Belgium, Lena Szabo, MD, PhD, Pediatric Center, Semmelweis University, Budapest, Hungary, Andrada Mirea, MD, PhD, National Clinical Hospital for Children Neurorehabilitation, Bucharest, Romania, Sherry Kodsy, MD, Maadi Military Hospitals, Cairo, Egypt, Areej Saleh, MD, Maadi Military Hospitals, Cairo, Egypt, Damjan Osredkar, MD, PhD, University Children's Hospital, Ljubljana, Slovenia, Jana Haberlova, MD, PhD, Motol University Hospital, Prague, Czech Republic, Anna Potulska-Chromik, MD, PhD, Department of Neurology, Medical University of Warsaw, Warsaw, Poland, Nina Butoianu, MD, Department of Paediatric Neurology, Alexandru Obregia Clinical Hospital, Bucharest, Romania, Paul Strijbos, PhD, F. Hoffmann-La Roche Ltd., Basel, Switzerland, Damien Eggenspieler, MSc, Sysnav

Duchenne muscular dystrophy (DMD) is characterized by severe and progressive muscle weakness. Assessing investigational drug efficacy in a reasonable timeframe is challenging due to a lack of objective, reliable, and sensitive outcome measures. This is especially true for patients <5 years old who can be poorly compliant with standardized assessments. The wearable, fit-for-purpose, magneto-inertial sensor, ActiMyo®/Syde®, was developed to assess motor function in an uncontrolled setting. One variable computed from such data, the 95th centile of stride velocity (SV95C), corresponding to the patient 5% fastest strides, was recently qualified as primary endpoint for ambulant DMD by the European Medicines Agency. The multicentre ActiLiège-Next study aims to gather 3-year longitudinal functional data from ambulant DMD patients and healthy controls aged 2-15 years old, using ActiMyo®/Syde®. Patients wear the sensor continuously during the first 3-12 months and for one month every 3 months afterwards. Control subjects wear the device for one month every 6-12 months. 74 ambulant DMD patients aged 2 to 14 years old (mean±SD: 7.38±2.76yo) and 53 controls of a similar age were enrolled. Preliminary analysis in subjects ≥5 years old showed excellent SV95C reliability, with an age-independent intra-class correlation of 0.97. The Pearson correlation with North Star Ambulatory Assessment, 6-Minute Walk Test and 4-stair climbing test was 0.71, 0.59, and -0.73 respectively (n=65-67). SV95C relative change from baseline at 6 and 12 months was 0% (n=36) and -7% (n=28) respectively, with a marked decline in patients ≥8 years old (-2.5% and -11% respectively, n=18 and 15). In addition to an update on external factors affecting SV95C measurement, the 1-year follow-up data of the subjects above 5 years old will be presented, including an analysis of factors influencing SV95C responsiveness. We will share for the first time the baseline compliance, SV95C reliability and known-group validity in the 2-5-year-old population.