{"entity":{"id":"i131-mibg","kind":"drug","name":"131I-MIBG (iobenguane I-131) therapy","aka":["Iobenguane I-131 (therapeutic)","131I-MIBG","Ultratrace iobenguane","iobenguane-i-131"],"tldr":"High-dose radioactive MIBG delivers radiation from inside neuroblastoma cells that take up noradrenaline; used for relapsed disease and tested in upfront therapy. A branded high-specific-activity form, Azedra, was approved for phaeochromocytoma and paraganglioma in 2018 and discontinued in 2024.","summary":"Response rate ~30-40% in relapsed/refractory MIBG-avid neuroblastoma (NANT, COG studies), with myelosuppression requiring stem-cell support at ≥12 mCi/kg. COG ANBL1531 randomised 131I-MIBG added to induction (primary results pending 2026).\n\nHigh-specific-activity iobenguane I-131 (Azedra, Progenics then Lantheus) was approved by the FDA in July 2018 for adults and children aged 12 and over with iobenguane scan-positive, unresectable, locally advanced or metastatic phaeochromocytoma or paraganglioma requiring systemic therapy, on a single-arm phase 2 study in which a quarter of patients halved their antihypertensive medication for at least six months and most had tumour control; it was the first approved therapy for these tumours. Lantheus discontinued manufacture in 2024, so patients rely on compounded low-specific-activity 131I-MIBG or lutetium-177 dotatate. Myelosuppression, secondary MDS and leukaemia, hypothyroidism and renal toxicity are the main risks; the diagnostic-dose iobenguane (AdreView) is an imaging agent covered under MIBG theranostics.","status":"established","asOf":"2026-09-07","wikipedia":"https://en.wikipedia.org/wiki/Iobenguane","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Iobenguane"},{"label":"US label (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/search.cfm?labeltype=all&query=iobenguane"},{"label":"NCI drug page","url":"https://www.cancer.gov/about-cancer/treatment/drugs/iobenguanei131"}],"tags":["nci-list"],"related":["lutathera"],"cancers":["neuroblastoma","neuroblastoma-high-risk","metastatic-ppgl","neuroendocrine"],"sections":[],"technologies":["mibg-theranostics","radioligand-therapy"],"targets":[],"drugs":[],"companies":["lantheus"],"institutions":[],"pathways":[],"terms":["radioiodine-term"],"trials":["anbl1531"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Azedra (the approved high-specific-activity product) and compounded 131I-MIBG are one INN, iobenguane I-131, so both are recorded here; the duplicate record iobenguane-i-131 redirects to this page."],"brand":"Azedra","modality":"Radioligand therapy (beta, norepinephrine transporter)","mechanism":"Norepinephrine transporter uptake of radio-iodinated benzylguanidine; 131I beta emission (2 mm range).","approvals":[{"region":"US","year":2018,"indication":"Iobenguane scan-positive unresectable, locally advanced or metastatic phaeochromocytoma or paraganglioma in patients 12 and older (Azedra, high-specific-activity form; discontinued 2024)"}],"mechanismSteps":[],"dosing":{"route":"IV","schedule":"12-18 mCi/kg single or tandem doses with autologous stem-cell support; thyroid blockade with potassium iodide","monitoring":"Radiation isolation, counts, thyroid function, secondary malignancy"},"toxicity":[],"access":[],"regulatoryEvents":[]},"route":"/drugs/i131-mibg/","neighbours":{"drug":[{"id":"lutathera","kind":"drug","name":"Lutetium-177 dotatate","route":"/drugs/lutathera/"}],"cancer":[{"id":"neuroblastoma-high-risk","kind":"cancer","name":"High-risk neuroblastoma","route":"/cancers/neuroblastoma-high-risk/"},{"id":"metastatic-ppgl","kind":"cancer","name":"Metastatic pheochromocytoma and paraganglioma","route":"/cancers/metastatic-ppgl/"},{"id":"neuroblastoma","kind":"cancer","name":"Neuroblastoma (paediatric)","route":"/cancers/neuroblastoma/"},{"id":"neuroendocrine","kind":"cancer","name":"Neuroendocrine tumours","route":"/cancers/neuroendocrine/"},{"id":"pheochromocytoma-paraganglioma","kind":"cancer","name":"Pheochromocytoma and paraganglioma (PPGL)","route":"/cancers/pheochromocytoma-paraganglioma/"}],"technology":[{"id":"mibg-theranostics","kind":"technology","name":"MIBG imaging and 131I-MIBG therapy","route":"/technologies/mibg-theranostics/"},{"id":"radioligand-therapy","kind":"technology","name":"Radioligand therapy (beta emitters)","route":"/technologies/radioligand-therapy/"}],"company":[{"id":"lantheus","kind":"company","name":"Lantheus","route":"/companies/lantheus/"}],"term":[{"id":"curie-siopen-score","kind":"term","name":"MIBG Curie and SIOPEN scores","route":"/terms/curie-siopen-score/"},{"id":"radioiodine-term","kind":"term","name":"Radioiodine therapy (I-131)","route":"/terms/radioiodine-term/"}],"trial":[{"id":"anbl1531","kind":"trial","name":"COG ANBL1531","route":"/trials/anbl1531/"}],"person":[{"id":"katherine-matthay","kind":"person","name":"Katherine K. Matthay","route":"/people/katherine-matthay/"}],"paper":[{"id":"paper-pryma-high-specific-activity-i131-mibg-ppgl-jnm-2019","kind":"paper","name":"Efficacy and safety of high-specific-activity 131I-MIBG therapy in advanced pheochromocytoma or paraganglioma","route":"/key-papers/paper-pryma-high-specific-activity-i131-mibg-ppgl-jnm-2019/"}],"roadmap":[{"id":"paediatric-oncology-roadmap","kind":"roadmap","name":"Paediatric oncology roadmap: cooperative-group cures → engineered immunity → drugs developed for children first","route":"/roadmaps/paediatric-oncology-roadmap/"}]}}