Flaws in Assessment Scales for Neuromuscular Conditions: Laurent Servais, MD, PhD

WATCH TIME: 7 minutes

"There is no magic solution as long as you stay with the concept of point assessment that is conducted by a human being in a hospital. Let alone the fact that at the end of the day, we would like to decrease the burden of trials, have less site visits, and survive."

Since the turn of the century, there have been several significant advances in the care for patients with neuromuscular disorders, mainly driven by palliative therapies like night-time assisted ventilation, anti-heart failure medications, and corticosteroids. For some conditions like Duchenne muscular dystrophy (DMD) and spinal muscular atrophy, there have been several approved disease-specific medications, including gene therapy, that have opened the door to a new realm of treatment possibilities. Despite these strides, assessing investigational drug efficacy in a reasonable timeframe has been a challenge because of a lack of objective, reliable, and sensitive outcome measures.

The wearable, fit-for-purpose, magneto-inertial sensor, ActiMyo, was developed to assess motor function in an uncontrolled setting. In the ActiLiege-Next study, patients with DMD wore the sensor continuously during the first 3-12 months and for 1 month every 3 months afterwards. In a preliminary analysis of children aged at least 5 years old, use of the sensor showed excellent reliability in testing 95th centile of stride velocity (SV95C), corresponding to the patient 5% fastest strides, with an age-independent intra-class correlation of 0.97. Presented at the 2024 Muscular Dystrophy Association (MDA) Clinical & Scientific Conference, held March 3-6, in Orlando, Florida, 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 above 8 years of age (–2.5% and –11%, respectively, n = 18 and n = 15).

Overall, these data highlight the potential benefits of SV95C as a more accurate measure of neuromuscular function in children with DMD. While many of the currently used scales and assessments are serviceable, there are several potential limiting factors to them, says Laurent Servais, MD, PhD. Servais, lead investigator of the ActiLiege-Next Study and professor of pediatric neuromuscular diseases at the University of Oxford, sat down in a recent interview to discuss the flaws in the traditional measures of neuromuscular function. He cited issues with patient motivation, in-person trips to hospitals, and those with intellectual disabilities and increased needs. Additionally, he spoke on SV95C as a qualified end point for ambulant DMD studies in the EU and when it could be expanded into other countries like the US.

REFERENCE
1. Servais L, Parinello G, Poleur M, et al. Longitudinal multicentric study to validate SV95C in ambulant DMD aged 2-15 years old. Presented at: MDA Clinical and Scientific Conference; March 3-6, 2024; Orlando, FL. M169