- Presence of symptomatic central nervous system (CNS) metastases or CNS metastases that require local CNS-directed therapy (e.g. radiotherapy or surgery) or increasing doses of corticosteroids within the prior 2 weeks. Patients with treated brain metastases should be neurologically stable (for 4 weeks post-treatment and prior to study enrollment) and off of steroids for at least 2 weeks before administration of any study treatment.