# Abarelix

Source: https://onco.cc/drugs/abarelix/  
OnCo record `abarelix` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Abarelix was the first GnRH antagonist for prostate cancer, approved in the United States in 2003 for men who could not take agonists, but allergic reactions restricted it and it was withdrawn from the US market in 2005; it remained available in Germany.

## Summary

Abarelix lowers testosterone to castrate levels within about a week without the flare seen with leuprolide or goserelin, which made it useful for men with impending spinal cord compression or severe bone pain. The FDA approved it in 2003 under a restricted programme because of immediate-onset systemic allergic reactions, and the manufacturer withdrew it from the US market in 2005. It was later approved in Germany. Degarelix, approved in 2008, took over the GnRH antagonist role in most countries.

## Fields

- Kind: Treatment
- Status: withdrawn
- Last checked: 2026-09-08
- Tags: gap-fill; chembl-universe
- Brand: Plenaxis
- Modality: GnRH antagonist peptide, intramuscular depot
- Mechanism: Blocks the pituitary GnRH receptor directly, so luteinising hormone and testosterone fall within days without the initial testosterone surge that GnRH agonists cause.
- Approvals: US 2003: Advanced symptomatic prostate cancer in men who cannot take GnRH agonists (restricted programme)

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Abarelix
- Wikipedia: https://en.wikipedia.org/wiki/Abarelix
- ChEMBL CHEMBL1201180: https://www.ebi.ac.uk/chembl/explore/compound/CHEMBL1201180

## Connected records

- cancers: [Prostate cancer](https://onco.cc/cancers/prostate/)
- technologies: [Endocrine therapy (SERMs, AIs, SERDs)](https://onco.cc/technologies/endocrine-therapy/)
- targets: [GnRH receptor (GNRHR)](https://onco.cc/targets/gnrhr/)
- drugs: [Degarelix](https://onco.cc/drugs/degarelix/), [Leuprolide (leuprorelin) and GnRH agonists](https://onco.cc/drugs/leuprolide/)

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JSON: https://onco.cc/api/v1/entities/abarelix.json