“PO-19 | Unraveling the spectrum of migraine resistant to treatments: searching for novel biological PHEnotypes and theRApeutic approaches (SPHERA project): M. Giraudo,1,2 R. De Icco,1,2 G. Vaghi,1,2 V. Grillo,1,2 F. Bighiani,1,2 M. Corrado,2 A. Antoniazzi,1,2 F. Cammarota,1,2 B. Agostini,1,2 A. Solfrizzi,1,2 M. Allena,2 E. Guaschino,2 N. Ghiotto,2 R. Greco,2 C. Demartini,2 A. Zanaboni,1,2 M. Francavilla,1,2 S. Facchetti,1,2 G. Sances,2 C. Tassorelli1,2 | 1Department of Brain and Behavioral Sciences, University of Pavia; 2Headache Science and Neurorehabilitation Unit, IRCCS Mondino Foundation, Pavia, Italy” (2025) Confinia Cephalalgica, 35(S1). doi:10.4081/cc.2025.15840.