Analytical validation of a multi-protein, serum-based assay for disease activity assessments in multiple sclerosis
Authors: Qureshi Ferhan , Hu Wayne , Loh Louisa , Patel Hemali , DeGuzman Maria , Becich Michael , da Costa Fatima Rubio , Gehman Victor , Zhang Fujun , Foley John , Chitnis Tanuja 
Published: May 2022

AbstractPurposeTo characterize and analytically validate the MSDA Test, a multi-protein, serum-based biomarker assay developed using Olink®PEA methodology.Experimental designTwo lots of the MSDA Test panel were manufactured and subjected to a comprehensive analytical characterization and validation protocol to detect biomarkers present in the serum of patients with MS. Biomarker concentrations were incorporated into a final algorithm used for calculating four Disease Pathway scores (Immunomodulation, Neuroinflammation, Myelin Biology, and Neuroaxonal Integrity) and an overall Disease Activity score.ResultsAnalytical characterization demonstrated that the multi-protein panel satisfied the criteria necessary for a fit-for-purpose validation considering the assay’s intended clinical use. This panel met acceptability criteria for 18 biomarkers included in the final algorithm out of 21 biomarkers evaluated. VCAN was omitted based on factors outside of analytical validation; COL4A1 and GH were excluded based on imprecision and diurnal variability, respectively. Performance of the four Disease Pathway and overall Disease Activity scores met the established acceptability criteria.Conclusions and clinical relevanceAnalytical validation of this multi-protein, serum-based assay is the first step in establishing its potential utility as a quantitative, minimally invasive, and scalable biomarker panel to enhance the standard of care for patients with MS.What is known and what is new in your work?What’s knownMultiple sclerosis (MS) has a complex disease course with variable clinical outcomes; early diagnosis and treatment are critical to management of MS.One key focus in MS research is the identification of biomarkers in biological fluids, such as cerebrospinal fluid or blood, to track pathogenesis, disease activity, and disease progression, which may lead to individualized disease management and improved quality of care.There currently are no validated clinical tests that leverage multiple blood biomarkers to track disease activity or progression in patients with MS.What’s newThe MS Disease Activity (MSDA) Test is a multi-protein, serum-based biomarker assay designed to quantitatively measure disease activity using the protein levels of biomarkers present in the serum of patients with MS.In this study, we evaluated 21 biomarkers, 18 of which were selected for inclusion in the MSDA Test, and extensively characterized the MSDA Test (individual biomarkers and algorithmic scores) by establishing the accuracy, precision, sensitivity, and robustness of the assay.This study serves as a critical first step in the validation of this multi-protein, serum-based assay, which will be a quantitative, minimally invasive, and scalable tool to improve MS disease management.Clinical relevanceMultiple sclerosis (MS) is a chronic, neurodegenerative, immune-mediated disease of the CNS. MS has a complex disease course with variable clinical outcomes. Although many treatments are effective in early stages of the relapsing/remitting form of the disease, early diagnosis and treatment are critical to managing disease activity and slowing disease progression. One of the major areas of focus in MS research is the identification of biomarkers in biological fluids, such as cerebrospinal fluid or blood, to track pathogenesis, disease activity, and disease progression, which can lead to individualized disease management and improved quality of care. Currently, there are no validated clinical tests that leverage multiple blood biomarkers to track disease activity or progression in patients with MS. Herein, we describe the analytical characterization and validation of a multi-protein, serum-based assay panel developed using Olink®PEA methodology. We demonstrate the extensive characterization of this multi-protein, serum-based assay and establish its accuracy, precision, sensitivity, and robustness. This report will be followed by a complementary clinical validation study investigating the correlation between the proteomic assay results and relevant clinical and radiographic endpoints for patients with MS.