XERECEPT® (hCRF) for Patients Requiring Dexamethasone to Treat Edema Associated With Brain Tumors

Inclusion Criteria: * Histologically confirmed diagnosis of a primary malignant brain tumor or, if metastatic, documentation and histology (if available) of primary source of cancer. * Patient must have 1 or more qualifying steroid-associated side effect(s) at Baseline. * Patient has required administration of dexamethasone to control symptoms of peritumoral edema for at least 30 days. * Stable dexamethasone dose of 4-24 mg/day for at least 14 days prior to Baseline. * Need for administration of dexamethasone to treat peritumoral brain edema (referenced above) has been documented by MRI or comparable diagnostic technology within 21 days of Baseline. * Karnofsky score of \> 50 at Screening and Baseline. * Capable of self-administration of subcutaneous injections twice daily for 12 weeks, or availability of assistance from caregiver. * Ability to provide written informed consent or, if unable to provide, have a legal guardian or representative provide written informed consent. * For women of childbearing potential: a negative serum pregnancy test at Screening. * Must be 18 years of age or older Exclusion Criteria: * Ongoing or anticipated need for surgery, radiosurgery or radiation therapy or the introduction of new chemotherapeutic regime within the first 5 weeks of study enrollment. Treatment with pre-study chemotherapy may continue. * Concurrent enrollment in any other investigational drug or device study, or plan to enroll in such a study during the first 5 weeks of treatment. * Systemic steroid use for any indication other than peritumoral brain edema. * Use or intended use of dexamethasone as an anti-emetic during Screening or Study * Non-compliance with dexamethasone or anticonvulsant therapy. * Clinical signs and symptoms of cerebral herniation. * Serious concomitant cardiovascular, pulmonary, renal, gastrointestinal or endocrine metabolic disease which could put the patient at unusual risk for study participation. * Confounding previous or concurrent neurological disorders that would interfere with adequate clinical evaluation. * Clinically significant head injury or chronic seizure disorder, if the condition results in functional impairment or is likely to interfere with evaluations. (Maintenance anticonvulsant therapy is allowed.) * Central nervous system infection. * Pregnancy, breastfeeding and/or refusal to practice birth control while in study, for women of childbearing potential. * Any conditions that are considered contraindications for patients to receive niacin, e.g. liver disease (with LFTs \> 3 times the upper limit of the norm),active peptic ulcer, arterial hemorrhage, asthma and known hypersensitivity to niacin.