On July 30, 2018, the U.S. Food and Drug Administration (FDA) approved iobenguane I 131 injection (Azedra) for intravenous use in the treatment of adults and adolescents aged 12 and older with unresectable pheochromocytoma or paraganglioma that have spread beyond the original tumor site and require systemic anticancer therapy. This is the first FDA-approved drug for this use.
Richard Pazdur, MD
“Many patients with these ultra-rare cancers can be treated with surgery or local therapies, but there are no effective systemic treatments for patients who experience tumor-related symptoms such as high blood pressure,” said Richard Pazdur, MD, Director of the FDA’s Oncology Center of Excellence and Acting Director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Patients will now have an approved therapy that has been shown to decrease the need for blood pressure medication and reduce tumor size in some patients.”
Clinical Trial Data
The efficacy of iobenguane I 131 injection was shown in a single-arm, open-label, clinical trial of 68 patients that measured the number of patients who experienced a 50% or greater reduction of all antihypertensive medications lasting for at least 6 months. This endpoint was supported by the secondary endpoint, overall tumor response measured by traditional imaging criteria. The study met the primary endpoint, with 17 of the 68 evaluable patients experiencing a 50% or greater reduction in antihypertensive medication for at least 6 months. Overall tumor response was achieved in 15 of the patients studied.
The most common severe side effects reported by patients receiving iobenguane I 131 injection in clinical trials included lymphopenia, neutropenia, thrombocytopenia, fatigue, anemia, increased international normalized ratio, nausea, dizziness, hypertension, and vomiting.
Iobenguane I 131 injection is a radioactive therapeutic agent and includes a warning about radiation exposure to patients and family members. Radiation exposure to others should be minimized while the patient is receiving iobenguane I 131. The risk of radiation exposure is greater in pediatric patients.
Other warnings and precautions include a risk of myelosuppression, underactive thyroid, elevations in blood pressure, renal failure or kidney injury, and pneumonitis. Myelodysplastic syndrome and acute leukemias were observed in patients who received iobenguane I 131.
For more information, visit FDA.gov. ■