Developing novel immunoassays specific for thyroid stimulating and TSHblocking autoantibodies

AbstractGraves’ disease (GD) is the most common cause of hyperthyroidism, accounting for 60 to 80 percent of more than 250 million cases of hyperthyroidism globally. Quantification of TSHR stimulating autoantibodies (TSAbs) can provide important guidance for the diagnosis and management of the disease, including predicting relapse or remission after initial anti-thyroid drug treatment or disease progression. However, TSHR blocking autoantibodies (TBAbs) can be also found in GD patients, complicating disease diagnosis and producing a spectrum of clinical presentations. For accurate diagnosis, assays to measure TSHR autoantibodies should be able to discriminate between TSAbs and TBAbs. Currently, TSAbs and TBAbs are measured either by cell-based bioassays or by binding assays. The cell-based bioassays can detect the total sum of functional TSAbs and TBAbs, but are time-consuming, laborious, and relatively expensive. Commercial binding assays are much simpler and faster. However, recent studies have clearly demonstrated that no commercially available binding assay can differentiate between TSAbs and TBAbs. Given the highly problematic lack of specificity of current binding assays, as well as the cost and time related drawbacks of the cell-based bioassays, there is a demonstrable need and commercial opportunity for simple, cost effective, and sensitive assays that can differentiate between TSAbs and TBAbs in patient blood samples. Developing and commercializing such assays are the goals of this project. In Phase I, we successfully used our novel epitope screening approach to identify unique peptide ligands that could differentiate between TSAbs and TBAbs. The goal of Phase II is to use these unique peptide ligands to develop, optimize and validate the novel diagnostic assays for GD, followed by testing their clinical utility. To accomplish this, we will use autoantibodies isolated from GD patient samples to identify additional peptide ligands (Aim 1) to assure high specificity and sensitivity of the assays. In Aim 2, we will use the best peptide ligands identified in Aim 1, together with those identified in Phase I, to develop specific assays with improved analytical performance. For a final validation of performance and clinical utility of the newly developed assays, we will compare the outcomes with two FDA-cleared assays on ~ 1,100 de-identified patient samples (Aim 3). Success of the Phase II project will allow Mediomics to establish our unique assays as simpler and more cost-effective alternatives to the cell-based bioassays, with a demonstrated ability to discriminate between TSAbs and TBAbs in patient samples. It will also allow Mediomics to develop rapid and cost-effective immunoassays for monitoring a range of other diseases, including infectious diseases. In Phase III, we will seek additional funding and collaborate with our corporate partners to enter clinical trials for FDA 510(k) clearance and to commercialize the assays as in vitro diagnostic immunoassays to monitor the TSAbs and TBAbs in human serum or plasma samples during the management of GD patients.Graves’ disease (GD) is an autoimmune disorder which accounts for 60 to 80 percent of ~250 million cases of hyperthyroidism globally. There is a demonstratable clinical need for the development of simple, cost-effective, and sensitive assays that can differentiate between two functionally distinct autoantibodies in patient blood samples. The goal of this project is to develop and commercialize such assays.