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.
Phase:
Phase 2
Details
Lead Sponsor:
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)