FDA Approves First Treatment for Rare Tumors of the Adrenal Gland

The US Food and Drug (FDA) administration has approved Progenics Pharmaceuticals' iobenguane I 131 (Azedra) injection for intravenous use for the treatment of adults and adolescents age 12 and older with rare tumors of the adrenal gland (pheochromocytoma or paraganglioma) that cannot be surgically removed (unresectable), have spread beyond the original tumor site, and require systemic anticancer therapy.

Iobenguane I 131 id the first treatment FDA-approved for use in rare adrenal tumors.

“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, in a recent statement. “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.”

A single-arm, open-label, clinical trial in 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 serves as the basis for iobenguane I 131’s approval. The secondary endpoint, an overall tumor response measured by traditional imaging criteria, supported the primary endpoint, which the study met. Seventeen (25%) of the 68 evaluable patients experienced a 50% or greater reduction of all antihypertensive medication for at least 6 months. Additionally, in 15 (22%) of the patients studied, an overall tumor response was achieved.

Low levels of white blood cells (lymphopenia), abnormally low count of a type of white blood cells (neutropenia), low blood platelet count (thrombocytopenia), fatigue, anemia, increased international normalized ratio (a laboratory test which measures blood clotting), nausea, dizziness, hypertension, and vomiting include the most common severe side effects reported by patients administered iobenguane I 131 in clinical trials.

A risk of lower levels of blood cells (myelosuppression), underactive thyroid, elevations in blood pressure, renal failure or kidney injury, and inflammation of lung tissue (pneumonitis) include additional warnings and precautions.

A warning about radiation exposure to patients and family members, which should be minimized while the patient is administered iobenguane I 131is included with the drug as it is a radioactive therapeutic agent. It should also be noted that pediatric patients are at a greater risk of radiation exposure, and developing fetuses can be harmed with iobenguane I 131 treatment. Infertility may also occur in males and females due to radiation exposure associated with iobenguane I 131.

Previously, iobenguane I 131 was granted a fast track designation, a breakthrough therapy designation, a priority review designation, and an orphan drug designation by the FDA.