Combination treatment with the investigational, selective KIT inhibitor PLX9486 plus sunitinib (Sutent) was safe and active in patients with relapsed or refractory gastrointestinal stromal tumors (GIST), a small phase I/II study found. Among 18 patients treated with the combination, one achieved a complete response, two had partial responses, and another had an unconfirmed partial response, according to Jonathan Trent, M.D., Ph.D., of the University of Miami Sylvester Comprehensive Cancer Center.