# Efficacy and safety of high-specific-activity 131I-MIBG therapy in advanced pheochromocytoma or paraganglioma

Source: https://onco.cc/key-papers/paper-pryma-high-specific-activity-i131-mibg-ppgl-jnm-2019/  
OnCo record `paper-pryma-high-specific-activity-i131-mibg-ppgl-jnm-2019` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A purified radioactive form of MIBG, taken up by adrenaline-producing tumour cells, let a quarter of patients halve their blood pressure medication for at least six months and shrank tumours in about one in five, leading to the first approved radiopharmaceutical for these tumours.

## Summary

Open-label single-arm multicentre phase 2 study of high-specific-activity iobenguane I-131 in patients with MIBG-avid unresectable or metastatic pheochromocytoma or paraganglioma, given as up to two therapeutic doses; 68 patients received at least one dose.

About a quarter of patients achieved the primary endpoint of at least a 50 percent reduction in antihypertensive medication for six months or more, objective responses occurred in about 22 percent, and most patients had disease control; myelosuppression was the main toxicity. The FDA approved the product (Azedra) in 2018.

## Fields

- Kind: Key paper
- Last checked: 2026-09-18
- Journal: Journal of Nuclear Medicine
- Year: 2019
- DOI: 10.2967/jnumed.118.217463
- Authors: Pryma DA, Chin BB, Noto RB, et al.
- Findings: At least a 50 percent reduction in antihypertensive medication for six months or longer in about a quarter of patients.; Objective tumour response in about 22 percent; myelosuppression was the main adverse effect.
- What it means: Radionuclide therapy is a standard option for MIBG-avid metastatic pheochromocytoma and paraganglioma; somatostatin receptor targeted lutetium therapy is the alternative for SSTR-avid disease.
- Caveats: Single-arm study with a blood pressure medication endpoint rather than survival.; The commercial product was later withdrawn from the US market for business reasons, limiting access.

## Sources

- J Nucl Med 2019: https://doi.org/10.2967/jnumed.118.217463
- PubMed: https://pubmed.ncbi.nlm.nih.gov/30291194/

## Connected records

- cancers: [Metastatic pheochromocytoma and paraganglioma](https://onco.cc/cancers/metastatic-ppgl/)
- drugs: [131I-MIBG (iobenguane I-131) therapy](https://onco.cc/drugs/i131-mibg/)
- journals: [Journal of Nuclear Medicine](https://onco.cc/journals/journal-of-nuclear-medicine/)

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