131MIBG to Treat Malignant Pheochromocytoma

Pheochromocytoma Clinical Trial

Official title: (131)I-Metaiodobenzylguanidine Treatment of Malignant Pheochromocytoma

Status Completed

Clinical Trial 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.

Clinical Trial 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. ;

Related Conditions & MeSH terms

• Pheochromocytoma

• NCT number: NCT00028106
• Study type: Interventional
• Source: National Institutes of Health Clinical Center (CC)
• Status: Completed
• Phase: Phase 2
• Start date: December 5, 2001
• Completion date: January 8, 2007