- The participant has active brain metastases or epidural disease; participants with stable brain metastases previously treated with whole brain radiation or radiosurgery or participants with epidural disease previously treated with radiation or surgery who are asymptomatic and do not require steroid treatment for at least 4 weeks before starting study treatment are eligible; neurosurgical resection of brain metastases or brain biopsy is permitted if completed at least 3 months before starting study treatment; baseline brain imaging with contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) scans for participants with known brain metastases is required to confirm eligibility