# Xgeva and Zometa

Xgeva and Zometa are the two standard bone-targeted agents most often discussed in metastatic cancer.

Both reduce skeletal-related events.

They differ in mechanism, side-effect profile, and administration.

### How they compare

| Parameter               | Xgeva (Denosumab)                                                                | Zometa (Zoledronic Acid)                                                                      |
| ----------------------- | -------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------- |
| Mechanism               | RANKL inhibitor and monoclonal antibody                                          | Bisphosphonate that inhibits osteoclasts                                                      |
| Skeletal-related events | Delays time to first skeletal-related event and was superior in some comparisons | Effective, but less so than Xgeva in those comparisons                                        |
| Overall survival        | Non-inferior to Zometa                                                           | Comparable to Xgeva                                                                           |
| Renal toxicity          | Lower risk and no dose adjustment required in this comparison                    | Higher risk and requires monitoring                                                           |
| Hypocalcaemia           | Higher incidence                                                                 | Lower incidence                                                                               |
| ONJ risk                | Similar risk to Zometa                                                           | Similar risk to Xgeva                                                                         |
| Administration          | Subcutaneous injection every 4 weeks                                             | IV infusion every 3 to 4 weeks, with some discussion of longer intervals in selected settings |

### Practical reading of the trade-off

Xgeva is usually the more potent RANKL-directed option for delaying skeletal-related events.

Zometa remains a major standard option, especially where cost, renal monitoring, rebound planning, or transition strategy matter.

The choice is often less about one being universally better and more about side-effect trade-offs, monitoring burden, and treatment context.

### Key References

A randomised phase III trial of denosumab versus zoledronic acid in patients with bone metastases from castration-resistant prostate cancer\
<https://ascopubs.org/doi/10.1200/jco.2010.28.18_suppl.lba4507>

Denosumab versus zoledronic acid in patients with bone metastases from solid tumours other than breast and prostate cancers or multiple myeloma\
<http://ascopubs.org/doi/10.1200/jco.2011.29.15_suppl.9115>

Effect of denosumab versus zoledronic acid in patients with castrate-resistant prostate cancer and bone metastases\
<http://ascopubs.org/doi/10.1200/jco.2011.29.15_suppl.4533>

Effects of denosumab versus zoledronic acid on pain in patients with metastatic breast cancer\
<http://ascopubs.org/doi/10.1200/jco.2010.28.15_suppl.1024>

### Bone Metastases in Breast Cancer pages

* [Bone Metastases in Breast Cancer](/myhealingcommunity-docs/breast-cancer/metastatic-disease-support/bone-metastases-in-breast-cancer.md)
* [Xgeva and Zometa](/myhealingcommunity-docs/breast-cancer/metastatic-disease-support/bone-metastases-in-breast-cancer/xgeva-and-zometa.md)
* [Integrative and Off-Label Strategies](/myhealingcommunity-docs/breast-cancer/metastatic-disease-support/bone-metastases-in-breast-cancer/integrative-and-off-label-strategies.md)
* [FOXM1 in Bone Metastasis](/myhealingcommunity-docs/breast-cancer/metastatic-disease-support/bone-metastases-in-breast-cancer/foxm1-in-bone-metastasis.md)
* [Bone Support and Protocol Notes](/myhealingcommunity-docs/breast-cancer/metastatic-disease-support/bone-metastases-in-breast-cancer/bone-support-and-protocol-notes.md)
* [Group Member Tips and Supporting Evidence](/myhealingcommunity-docs/breast-cancer/metastatic-disease-support/bone-metastases-in-breast-cancer/group-member-tips-and-supporting-evidence.md)

### Also relevant

* [SABR for BC Bone Mets 2025 Study Summary](/myhealingcommunity-docs/breast-cancer/metastatic-disease-support/bone-metastases-in-breast-cancer/sabr-for-bc-bone-mets-2025-study-summary.md)


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