Correlation Between MG Symptoms PRO and Existing MG-Specific Outcome Scores in the Phase 3 MycarinG Study: Post Hoc Analysis
Robert M. Pascuzzi1, Carlo Antozzi2, Ali A. Habib3, Henry J. Kaminski4, Sabrina Sacconi5, Kimiaki Utsugisawa6, John Vissing7, Antoine Regnault8, Jos Bloemers9, Fiona Grimson10, Thaïs Tarancón11, Vera Bril12
1Neurology Department, Indiana University School of Medicine, Indiana University Health, Indianapolis, IN, USA, 2Neuroimmunology and Muscle Pathology Unit, Multiple Sclerosis Center, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico, Istituto Nazionale Neurologico Carlo Besta, Milan, Italy, 3MDA ALS & Neuromuscular Center, Department of Neurology, University of California, Irvine, Orange, CA, USA, 4Department of Neurology & Rehabilitation Medicine, George Washington University, Washington, DC, USA, 5Université Côte d'Azur, Peripheral Nervous System & Muscle Department, Pasteur 2 Hospital, Centre Hospitalier Universitaire de Nice, Nice, France, 6Department of Neurology, Hanamaki General Hospital, Hanamaki, Japan, 7Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark, 8Modus Outcomes, A Division of THREAD, Lyon, France, 9UCB, Brussels, Belgium, 10UCB, Slough, UK, 11UCB, Madrid, Spain, 12University Health Network, Toronto, ON, Canada
Objective:
To evaluate the correlation between Myasthenia Gravis (MG) Symptoms Patient-Reported Outcome (MG Symptoms PRO) scale scores and MG Activities of Daily Living (MG-ADL) and Quantitative MG (QMG) subdomain scores using data from the Phase 3 MycarinG study (NCT03971422) of rozanolixizumab in patients with generalized MG.
Background:
MG Symptoms PRO is a novel tool comprising five independent scales to measure MG symptoms: Muscle Weakness Fatigability, Physical Fatigue, Bulbar Muscle Weakness, Ocular Muscle Weakness and Respiratory Muscle Weakness.
Design/Methods:
In MycarinG, patients were randomly assigned 1:1:1 to once-weekly subcutaneous rozanolixizumab 7 mg/kg, 10 mg/kg or placebo for 6 weeks. Outcome assessments included changes in MG-ADL (primary endpoint at Day 43), QMG and three MG Symptoms PRO scales. This post hoc analysis used MycarinG baseline scores (prior to treatment) to evaluate the correlation between MG Symptoms PRO scales and subdomains of MG-ADL and QMG scores (ocular, bulbar, respiratory and limb weakness/gross motor), using the Pearson coefficient between each pair of scores (strong: ≥0.7; moderate: 0.5–<0.7; weak: 0.3–<0.5).
Results:
Overall, 200 patients were enrolled in MycarinG. Correlation coefficients between MG Symptoms PRO scales and MG-ADL subdomain scores were strong between Ocular Muscle Weakness/ocular subdomain (0.78) and Bulbar Muscle Weakness/bulbar subdomain (0.72), and moderate between Respiratory Muscle Weakness/respiratory subdomain (0.58), Physical Fatigue/limb weakness subdomain (0.60) and Muscle Weakness Fatigability/bulbar subdomain (0.52). Correlation coefficients between MG Symptoms PRO scales and QMG subdomain scores were generally weak, with one moderate correlation between Bulbar Muscle Weakness/bulbar subdomain (0.50).
Conclusions:
As expected, the five MG Symptoms PRO scales, which incorporate additional concepts such as physical fatigue, had stronger correlations with comparable concepts in MG-ADL and weaker correlations with QMG likely resulting from comparing patient- and clinician-reported data with different recall times. MG Symptoms PRO can complement existing MG-specific outcome measures to provide a granular assessment of the broad-ranging symptoms of MG.
Disclaimer: Abstracts were not reviewed by Neurology® and do not reflect the views of Neurology® editors or staff.