On July 30, 2018, the FDA approved iobenguane I-131 (Azedra®, Progenics Pharmaceuticals), a radioactive therapeutic agent, for the treatment of adult and paediatric patients ≥12 years with iobenguane scan positive, locally advanced or metastatic pheochromocytoma or paraganglioma (PPGL) not amenable to surgery and indicated for systemic therapy.

Study IB12B

The FDA based her opinion on the open-label, single-arm, multicentre Study IB12B (NCT00874614) in patients ≥12 years. Participants with an iobenguane scan-positive, unresectable, locally advanced or metastatic PPGL were eligible for participation. A reduction of ≥50% of all antihypertensive medication for ≥6 months was observed in 17 (25%; 95% CI, 16-37%) of the 68 evaluable patients. A tumour response by RECIST 1.0 was recorded in 15 (22%; 95% CI, 14-33%) patients. A duration of response ≥6 months was noted in 53% of the responders.

Safety

Common grade 3-4 adverse reactions occurring in ≥10% of patients in the Study IB12B included lymphopenia, neutropenia, thrombocytopenia, fatigue, anaemia, increased international normalised ratio (INR), nausea, dizziness, hypertension, and vomiting. Myelodysplastic syndrome or acute leukaemia was observed in 6.8% of patients who received a therapeutic dose of iobenguane I-131 (pooled safety population).

Azedra® full prescribing information