OncologyFDA Approved

Abarelix (Plenaxis)

Intramuscular injection

Overview

Abarelix is a synthetic decapeptide that functions as a gonadotropin-releasing hormone (GnRH) receptor antagonist. It competitively blocks pituitary GnRH receptors, producing immediate suppression of luteinizing hormone, follicle-stimulating hormone, and testosterone without the initial surge associated with GnRH agonists.

Mechanism of Action

The peptide was developed for treatment of advanced symptomatic prostate cancer in patients who refused surgical castration and were not candidates for GnRH agonist therapy. Its structure incorporates multiple unnatural amino acids to optimize receptor antagonism and pharmacokinetic properties..

Research Summary & Key Findings

Abarelix received FDA approval in 2003 but was voluntarily withdrawn from the U.S. market in 2005 due to limited commercial demand and the availability of alternative androgen deprivation therapies. Clinical trials demonstrated rapid testosterone suppression in the majority of patients, but the drug carried a risk of immediate-onset systemic allergic reactions in approximately 1% of patients, necessitating a risk management program. It remains approved in some international markets under restricted prescribing conditions.

Clinical Status

FDA Approved

Abarelix (Plenaxis) has received FDA approval and is available for clinical use under appropriate medical supervision. Consult a qualified healthcare provider for prescribing information.

Administration Routes

Intramuscular injection

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Disclaimer: This information is provided for educational and research purposes only. It is not intended as medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any peptide therapy. The Peptide Association does not endorse or recommend any specific treatment protocol.