- Untreated or unstable central nervous system (CNS) metastases. Subjects with treated and stably controlled CNS metastases are eligible for cohorts A and B of the phase 2 part of the study if definitive therapy has been administered (surgery and/or radiation therapy), there is no planned treatment for brain metastases, and the subject is clinically stable and is off corticosteroids or on a stable dose of corticosteroids for at least 2 weeks prior to enrollment