- Known brain metastases or cranial epidural disease unless adequately treated with radiotherapy, radiosurgery, or surgery and stable for at least 4 weeks of enrollment as documented by MRI or CT imaging. Treated brain metastases are defined as having no ongoing requirement for steroids (must be off steroids for at least 4 weeks) and no evidence of progression or hemorrhage after treatment for at least 4 weeks of enrollment as documented by MRI or CT imaging.