Development of a Full Qualification Package (FQP) for the PROMISnq Short Form v2.0 - Physical Function - Multiple Sclerosis 15a (DDT COA #000123) - ABSTRACT Over 1 million people in the United States are living with multiple sclerosis (MS), a disease that has significant impacts on physical functioning and, consequently, health-related quality of life. However, a psychometrically sound, publicly available measure of physical function optimized for persons with MS developed from the patient perspective has not been recognized by FDA as fit- for-purpose for use in drug development. We propose the preparation and submission of a Full Qualification Package (FQP) to support the qualification of the PROMIS / Quality of Life in Neurological Disorders™ (Neuro-QoL™) Physical Function Measure for Multiple Sclerosis (PROMISnq PFMS—15a) as a patient-reported outcome (PRO) measure of physical function in people diagnosed with all forms of MS. A measure of physical function was accepted into the Center for Drug Evaluation and Research’s (CDER’s) Clinical Outcome Assessment (COA) Qualification Program under DDT #000123 on June 21, 2017. The PRO Consortium’s MS Working Group selected the PROMISnq PFMS—15a as the physical function measure for qualification as it has been optimized for use in persons with MS and has qualitative evidence supporting its content validity. Next, a Qualification Plan (QP) was submitted to FDA on November 29, 2021. The QP addressed the Working Group’s research plan for obtaining quantitative evidence to support qualification of the measure. After FDA acceptance of the QP, the next steps will be to analyze cross-sectional and longitudinal datasets from the United Kingdom MS Register Study and the University of Washington MS Psychometric Evaluation Study to generate quantitative evidence and to prepare and submit an FQP. Our approach includes 3 aims. For Aim 1, we will analyze available cross-sectional and longitudinal datasets that include the PROMISnq PFMS—15a in accordance with the accepted QP and statistical analysis plan to document its validity, reliability, and responsiveness as an outcome measure in people with all forms of MS. For Aim 2, we will prepare an FQP for the PROMISnq PFMS—15a using the CDER COA FQP content outline and integrate all evidence supporting the measure, including results of the completed qualitative and quantitative research. Aim 3 will involve the submission of the FQP with all necessary appendices and attachments, including a user manual and the associated analysis datasets and programming code. The goal of this project will be a publicly available and accessible PRO measure for assessing physical function in MS clinical trials for people with all forms of MS. As such, qualifying the PROMISnq PFMS—15a will fill a critical gap in the measurement of physical function in MS treatment trials.