Study of AMN107 With Imatinib in Gastrointestinal Stromal Tumors (GIST)

Inclusion Criteria: * Patients with gastrointestinal stromal tumor (GIST). * Patients who have had disease progression during imatinib therapy with 800 mg. * Ability to understand and willingness to sign a written informed consent document. Exclusion Criteria: * Patients with prior or concomitant malignancies other than GIST with the exception of previous or concomitant basal cell skin cancer or previous cervical carcinoma in situ. * A history of impaired cardiac function or uncontrolled cardiovascular disease. * Severe and/or uncontrolled concurrent disease that could cause unacceptable safety risks such as impairment of gastrointestinal (GI) function or GI disease that may significantly alter the absorption of AMN107. * Currently taking certain medications that could affect an electrocardiogram result. * Women who are pregnant or breast feeding. * Patients unwilling or unable to comply with the protocol. NOTE: Additional inclusion and/ or exclusion criteria may apply.