A multicenter, dose-finding, phase 1b study of imatinib in combination with alpelisib as third-line treatment in patients with advanced gastrointestinal stromal tumor oleh Maria A. Pantaleo, Michael C. Heinrich, Antoine Italiano, Claudia Valverde, Patrick Schöffski, Giovanni Grignani, Anna K. L. Reyners, Sebastian Bauer, Peter Reichardt, Daniel Stark, Ghimja Berhanu, Ulrike Brandt, Tommaso Stefanelli, Hans Gelderblom