Molinari, Angelo Claudio. 2026. “CO-37 | STEW-EFA STUDY: MULTICENTER EVALUATION OF ONE-STAGE AND CHROMOGENIC ASSAYS FOR EFANESOCTOCOG ALFA MEASUREMENT ON STAGO AND WERFEN PLATFORMS: A.C. Molinari1, M. Marchetti2, A. Catalano3, L. Contino4, R. De Cristofaro5, A.B. Federici6, T. Martini7, I. Quaglia8, R. Rossi9, R. Santoro10, A. Tripodi11, A. Valpreda12 | 1Regional Reference Centre for Hemorrhagic Diseases, Department of Hemato-Oncology, IRCCS Istituto Giannina Gaslini, Genova, Italy; 2Department of Immunohematology and Transfusion Medicine, ASST Papa Giovanni XXIII, Bergamo, Italy; 3Società Per La Promozione dell’educazione Medica (S.P.E.Me), Italy; 4Hemostasis and Thrombosis Unit, AOU SS Antonio E Biagio E C Arrigo, Alessandria, Italy; 5Dipartimento Di Medicina E Chirurgia Traslazionale, Facoltà Di Medicina E Chirurgia "Agostino Gemelli," Università Cattolica S. Cuore, Roma, Italy - Servizio Malattie Emorragiche E Trombotiche, Fondazione Policlinico Universitario "A. Gemelli‘ Istituto Di Ricerca E Cura a Carattere Scientifico, Roma, Italy; 6School of Medicine and Surgery, University of Milan-Bicocca, Milano, Italy; 7Hemophilia Centre, Immune-Hematology and Transfusion Medicine, University Hospital “Città Della Salute E Della Scienza’, Torino, Italy; 8Center for Thrombosis and Hemorrhagic Diseases, IRCCS Humanitas Research Hospital Rozzano, Milan, Italy; 9Laboratory of Clinical Chemistry and Hematology, University Hospital of Parma, Italy; 10Hemophilia, Hemostasis, and Thrombosis Unit, Azienda Ospedaliero Universitaria Dulbecco, Catanzaro, Italy; 11IRCCS Ca’ Granda Maggiore Hospital Foundation and Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milano, Italy; 12Central Laboratory Baldi and Riberi, AOU Città Della Salute E Della Scienza, Turin, Italy, Reference Laboratory of the Regional Center for Hemostasis and Thrombosis”. Bleeding, Thrombosis and Vascular Biology 5 (s2). https://doi.org/10.4081/btvb.2026.647.