The FDA approved Azedra (iobenguane I 131, Progenics Pharmaceuticals) 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. This is the first FDA-approved drug for this use.
The efficacy of Azedra was shown in a single-arm, open-label, clinical trial in 68 patients that measured the number of patients who experienced a 50 percent or greater reduction of all antihypertensive medications lasting for at least six 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 (25 percent) of the 68 evaluable patients experiencing a 50 percent or greater reduction of all antihypertensive medication for at least six months. Overall tumor response was achieved in 15 (22 percent) of the patients studied.
The most common severe side effects reported by patients in clinical trials included lymphopenia, neutropenia, thrombocytopenia, fatigue, anemia, increased international normalized ratio, nausea, dizziness, hypertension, and vomiting.
As it is a radioactive therapeutic agent, Azedra includes a warning to patients about radiation exposure, which should be minimized while the patient is receiving the drug. 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 Azedra, and the magnitude of this risk will continue to be studied. Azedra can cause harm to a developing fetus; women should be advised of the potential risk to the fetus and to use effective contraception after receiving the drug. Radiation exposure associated with Azedra may cause infertility in males and females.
Source: FDA.gov, July 30, 2018