Symptomatic Treated (surgery, radiation therapy) but not clinically and radiographically stable one month after local therapy, or Asymptomatic and untreated but > 1 cm in the longest dimension Patients with small (≤ 1 cm in the longest dimension), asymptomatic brain metastases that do not need immediate local therapy can be enrolled with the approval of the GSK medical monitor. Subjects on a stable dose of corticosteroids for more than one month, or those who have been off corticosteroids for at least two weeks can be enrolled. Subjects must also be off of enzyme-inducing anticonvulsants for more than four weeks; Note: Any brain metastases is exclusionary for Part A (must be excluded by prior imaging);