Symptomatic Treated (surgery, radiation therapy), but not clinically and radiographically stable for a period of at least one month prior to study entry, or Asymptomatic and untreated but > 1 cm in the longest dimension Exception: Subjects with small (≤ 1 cm in the longest dimension), asymptomatic brain metastases that do not need immediate local therapy can be enrolled. Subjects on a stable dose of corticosteroids for more than one month, or those who have been off corticosteroids for at least 2 weeks can be enrolled. Subjects must also be off of enzyme-inducing anticonvulsants for more than 4 weeks;