Long-term follow-up results of the multicenter phase II trial of regorafenib in patients with metastatic and/or unresectable GI stromal tumor after failure of standard tyrosine kinase inhibitor therapy

E. Ben-Ami, C. M. Barysauskas, M. von Mehren, M. C. Heinrich, C. L. Corless, J. E. Butrynski, J. A. Morgan, A. J. Wagner, E. Choy, J. T. Yap, A. D. Van den Abbeele, S. M. Solomon, J. A. Fletcher, G. D. Demetri, Suzanne George