- Subject has symptomatic central nervous system (CNS) metastases or subject has evidence of unstable CNS metastases even if asymptomatic (e.g., progression on scans). Subjects with previously treated CNS metastases are eligible, if subject is clinically stable and have no evidence of CNS progression by imaging for at least 4 weeks prior to start of study treatment and are not requiring immunosuppressive doses of systemic steroids (> 30 mg per day of hydrocortisone or > 10 mg per day of prednisone or equivalent) for longer than 2 weeks.