DEVELOPMENT OF THE SPORADIC INCLUSION BODY MYOSITIS PHYSICAL FUNCTIONING ASSESSMENT

Introduction: Sporadic inclusion body myositis (sIBM) is a progressive idiopathic inflammatory myopathy characterized by atrophy and weakness of proximal and distal muscle groups that results in a loss of independence and the need for assistive devices and supportive care. To assess treatment benefit of new therapies, a patient-reported outcome measure of physical function was developed. Methods: The tool was rigorously developed in accordance with the United States Food and Drug Administration (FDA) patient-reported outcomes (PRO) guidance. A single-visit, observational study was conducted. Standard qualitative analytical methods were employed to analyze interview data and generate questionnaire items. Results: Twenty concept elicitation and 19 cognitive debriefing interviews were conducted, and 6 expert physicians were consulted. The tool consists of 11 items scored on a 0-10 numerical rating scale. Subjects completed the questionnaire utilizing either paper or electronic administration. Conclusion: We have developed a PRO tool in alignment with FDA PRO guidance for use in the functional assessment of treatment benefit in sIBM.