131MIBG to Treat Malignant Pheochromocytoma
Condition: Pheochromocytoma
MeSH terms: Pheochromocytoma
Study type: Interventional
Phase: Phase 2

Summary: 
      This study will evaluate the effectiveness of 131MIBG in treating malignant pheochromocytoma
      and whether sensitization medications improve the response to treatment. Pheochromocytoma is
      a rare type of tumor that usually occurs in the adrenal glands. The tumor cells release
      chemicals like adrenaline that can cause large increases in blood pressure and pulse rate,
      with serious health consequences. Tumor in the adrenal glands usually can be removed
      surgically, but if the pheochromocytoma is malignant-i.e., has spread to many sites in the
      body-or is located in places where surgery is difficult or impossible, no satisfactory
      treatment is available. 131MIBG is a combination of an adrenaline-like chemical and a
      radioactive form of iodine. The 131MIBG attaches to the tumor cells and the high
      concentration of radioactive iodine kills them. Previous studies using 131MIBG to treat
      pheochromocytoma had a 36% response rate in terms of complete or partial improvement. This
      study will examine whether adding other sensitization medications to the 131MIBG treatment
      regimen will enhance its effectiveness in reducing the size and number of tumors.

      Patients 18 years of age and older with malignant or inoperable pheochromocytoma may be
      eligible for this 18-month study. Candidates will be screened with various tests and
      procedures, which may include a medical history, physical examination, blood and urine tests,
      lung function studies, electrocardiogram, echocardiogram, computed tomography (CT), magnetic
      resonance imaging (MRI), positron emission tomography (PET), and bone scans and other scans
      using radioactive MIBG and octreotide.

      Participants will be randomly assigned to one of two treatment groups: 1) 131MIBG plus
      sensitization medications, or 2) 131MIBG alone. All patients will be hospitalized 3 to 5 days
      for each 131MIBG treatment. The drug will be infused through a vein (intravenously, or I.V.)
      over 10 to 30 minutes. Patients will receive up to 3 treatments, separated by at least 3
      months. All patients will also take potassium to protect the thyroid gland from radioactive
      iodine generated by the 131MIBG. The potassium is taken twice a day for 30 days, beginning
      the day before the 131MIBG treatment. Patients in the sensitization group will receive the
      following additional drugs for sensitization: methylprednisolone, intravenously a few minutes
      before 131MIBG treatment; Roaccutan, by mouth (capsules) twice a day for 6 weeks before
      treatment; Demser, by mouth 3 times a week for 1 week before treatment, and Carbidopa, by
      mouth every 6 hours for 4 days before treatment.

      After each treatment, patients will have a clinical evaluation and periodic blood tests to
      check for adverse side effects of radiotherapy. Follow-up visits at NIH will be scheduled at
      12 and 18 months after the first 131MIBG treatment for clinical, laboratory and imaging
      tests. Patients who had tumors in the lungs before treatment will have lung function tests 1,
      3, and 6 months after each treatment. CT, MRI 131MIBG, and PET scanning will be done 1 week
      before each treatment.

      Patients who have tumors that have grown by more than 25% and none that have shrunk by more
      than 50% or who have developed one or more new tumors while on 131MIBG treatment will be
      taken off the study.
    

Detailed description: 
      Pheochromocytomas are tumors of chromaffin cells that synthesize catecholamines. This project
      tests the efficacy of radiotoxic treatment of malignant pheochromocytoma using
      (131)I-metaiodobenzylguanidine [(131)I-MIBG], and in particular, tests whether pre-treatment
      with enhancer pharmaceuticals increases the efficacy of experimental (131)I-MIBG treatment in
      reducing the size and number of tumors and the tumor burden.
    

Intervention name(s): [131]I-MIBG; 6-[18F]Fluorodopamine; [123]I-MIBG
Intervention type(s): Drug; Drug; Drug
Intervention MeSH terms: 3-Iodobenzylguanidine
Primary purpose: Treatment
Keywords: Cancer; Metastasis; Fluorodopamine; PET; Methylprednisolone; Catecholamines; Metanephrines; Alpha-Methyl-Para-Tyrosine; Retinoic Acid; Carbidopa