Cotara® is an experimental new treatment that links a radioactive isotope (iodine 131) to a targeted monoclonal antibody. This monoclonal antibody is designed to bind tumor cells and deliver radiation directly to the center of the tumor mass while minimizing effects on normal tissues. Cotara® thus literally destroys the tumor "from the inside out". This may be an effective treatment for glioblastoma multiforme, a malignant type of brain cancer.

To confirm the safety and tolerability of the Maximum Tolerated Dose (MTD) of 131I-chTNT-1/B MAb given as a single interstitial infusion in patients with glioblastoma multiforme at first relapse.

To estimate overall survival, progression free survival and proportion of patients alive at six months after treatment.

Inclusion Criteria:

• Histologically confirmed GBM
• Clinical Target Volume between 5 and 60 cc (inclusive)
• 18 to 75 years old (inclusive)
• Karnofsky Performance Status ≥ 70 percent
• If on steroids dose (± 4mg/day) must be stable for at least two weeks prior to screening/baseline visit. If not on steroids for two weeks prior to screening/baseline visit are allowed
• Adequate hematology
• Adequate renal function
• Adequate liver function

Exclusion Criteria:

• Infratentorial tumor(s), tumor(s) that communicate with the ventricles or intraventricular disease
• Bilateral non-contiguous gadolinium enhancing tumor
• Diffuse disease (i.e., any satellite lesions less than 1.5 cm from anticipated location of any catheter tip or less than two satellite lesions)
• Known or suspected allergy to study medication or iodine
• Surgical procedure within four weeks of baseline
• More than one prior chemotherapy regime or chemotherapy within four weeks (nitrosourea-based within six weeks) of baseline
• Radiation therapy within four weeks of baseline
• Investigational agent within last 30 days
• Previous treatment with any chimeric monoclonal antibody
• HIV positive
• Evidence of active hepatitis