- Subject has known symptomatic brain metastases or leptomeningeal involvement as assessed by CT scan or MRI. Subjects with stable asymptomatic brain metastases or leptomeningeal disease are eligible if they have not required new treatments for this disease in a 28 day period before the first dose of study drug, and anticonvulsants and steroids have not been administered for a period of 2 weeks prior to the first dose of study drug.