Inhibitors of the activin receptor signaling pathways (IASPs) in sports drug testing

Code: 23A13MT

Members of the transforming growth factor beta (TGF-β) superfamily such as myostatin (MSTN), activin A, and GDF-11, are dimeric cytokines signaling through activin receptors. They play important regulative roles in different biological processes as for example the formation of muscle and red blood cells. Therefore, inhibitors of the activin receptor signaling pathways (IASPs) can be considered as potential performance-enhancing agents in sports, which are included in sections S2 (“Peptide hormones, growth factors, related substances and mimetics”) and S4 (“Hormone and metabolic modulators”) of the WADA Prohibited List. They comprise targeted (e.g. anti-MSTN antibodies) as well as multi-targeting approaches (e.g. receptor competitors and anti-ActRII antibodies), and for several drug candidates, doping control detection methods based on electrophoretic techniques and Western blotting or LC-HRMS/MS have been proactively developed within the last years. This is of utmost importance, as, even without clinical approval, reference material for such emerging drugs is often available for research purposes and/or distributed on the black market. Therefore, the aim of this research project is to develop a combined mass spectrometric detection assay for the novel anti-activin A antibody Garetosmab and other IASPs such as Sotatercept, Domagrozumab, and Luspatercept. A combined extraction of the target analytes from plasma/serum can be achieved by using NHS magnetic sepharose beads coupled to different TGF-β cytokines such as activin A, MSTN, and GDF-11. Subsequent LC-HRMS/MS analysis will not only allow for an unambiguous identification of the target analytes based on the amino acid level, but also retrospective sample evaluation for the presence of novel IASPs binding to one of the TGF-β cytokines employed for affinity purification.