Inclusion Criteria:

1. Histologically confirmed diagnosis of GIST which is unresectable and/or metastatic
and either:

- have not received any prior anti-neoplastic therapy other than adjuvant
imatinib. Note: newly diagnosed patients may have received up to 14 days of
treatment with imatinib for disease management while awaiting entry to the study
or

- recurrent GIST after stopping adjuvant treatment with imatinib and no subsequent
treatment with any other therapies.

2. At least one measurable site of disease on CT/MRI scan

3. Performance status ≤ 2 (capable of self-care but unable to carry out any work)

4. Normal organ, electrolyte and marrow function

Exclusion Criteria:

1. Any prior anti-neoplastic therapy with the exception of patients who have received
adjuvant imatinib or patients with newly diagnosed metastatic/ unresectable GIST
whose disease requires therapy while awaiting entry to the study.

2. Disease progression during adjuvant therapy with imatinib

3. History of active malignancy (other than GIST) within 10 years prior to study entry
with the exception of previous or concomitant basal cell skin cancer, previous
cervical carcinoma in situ.

4. Impaired cardiac function

Other protocol-defined inclusion/exclusion criteria may apply