MEK162 in Combination With Imatinib Mesylate in Patients With Untreated Advanced Gastrointestinal Stromal Tumor (GIST)

Patients should take the study drug with a glass of water. MEK162 can be taken with or without food.

Following informed consent, the first 20 mandatory patients, except for patients who have already been treated with imatinib prior to consent, and subsequent voluntary patients enrolled on the phase II portion of the trial will undergo research biopsies. Patients should hold both imatinib and MEK162 doses on the day they undergo a biopsy.