WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 100010

CAS#: 183552-38-7 (free base)

Description: Abarelix is a synthetic decapeptide and antagonist of naturally occurring gonadotropin-releasing hormone (GnRH). Abarelix directly and competitively binds to and blocks the gonadotropin releasing hormone receptor in the anterior pituitary gland, thereby inhibiting the secretion and release of luteinizing hormone (LH) and follicle stimulating hormone (FSH). In males, the inhibition of LH secretion prevents the release of testosterone. As a result, this may relieve symptoms associated with prostate hypertrophy or prostate cancer, since testosterone is required to sustain prostate growth.

Chemical Structure

CAS# 183552-38-7 (free base)

Theoretical Analysis

MedKoo Cat#: 100010
Name: Abarelix
CAS#: 183552-38-7 (free base)
Chemical Formula: C72H95ClN14O14
Exact Mass: 1414.68407
Molecular Weight: 1416.06
Elemental Analysis: C, 61.07; H, 6.76; Cl, 2.50; N, 13.85; O, 15.82

Price and Availability

Size Price Availability Quantity
5.0mg USD 350.0 2 Weeks
10.0mg USD 550.0 2 Weeks
25.0mg USD 1250.0 2 Weeks
50.0mg USD 2250.0 2 Weeks
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Related CAS #: 785804-17-3 (acetate)   183552-38-7 (free base)    

Synonym: PPI149; PPI-149; PPI 149; R3827; R-3827; R 3827. Abarelix; Abarelix acetate. Brand name: Plenaxis.

IUPAC/Chemical Name: (2R)-2-[[(2S)-2-[[(2S)-2-[[(2R)-2-[[(2R)-2-[[(2R)-2-acetamido-3-naphthalen-2-ylpropanoyl]amino]-3-(4-chlorophenyl)propanoyl]amino]-3-pyridin-3-ylpropanoyl]amino]-3-hydroxypropanoyl]-methylamino]-3-(4-hydroxyphenyl)propanoyl]amino]-N-[(2S)-1-[[(2S)-1-[(2S)-2-[[(2R)-1-amino-1-oxopropan-2-yl]carbamoyl]pyrrolidin-1-yl]-1-oxo-6-(propan-2-ylamino)hexan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]butanediamide


InChi Code: InChI=1S/C72H95ClN14O14/c1-41(2)32-54(64(93)80-53(17-10-11-30-77-42(3)4)72(101)87-31-13-18-60(87)69(98)78-43(5)63(75)92)81-68(97)58(38-62(74)91)84-70(99)61(37-46-22-27-52(90)28-23-46)86(7)71(100)59(40-88)85-67(96)57(36-48-14-12-29-76-39-48)83-66(95)56(34-45-20-25-51(73)26-21-45)82-65(94)55(79-44(6)89)35-47-19-24-49-15-8-9-16-50(49)33-47/h8-9,12,14-16,19-29,33,39,41-43,53-61,77,88,90H,10-11,13,17-18,30-32,34-38,40H2,1-7H3,(H2,74,91)(H2,75,92)(H,78,98)(H,79,89)(H,80,93)(H,81,97)(H,82,94)(H,83,95)(H,84,99)(H,85,96)/t43-,53+,54+,55-,56-,57-,58-,59+,60+,61+/m1/s1

SMILES Code: O=C(N[C@@H](CC(C)C)C(N[C@@H](CCCCNC(C)C)C(N1[C@H](C(N[C@H](C)C(N)=O)=O)CCC1)=O)=O)[C@H](NC([C@@H](N(C([C@@H](NC([C@H](NC([C@H](NC([C@H](NC(C)=O)CC2=CC=C3C=CC=CC3=C2)=O)CC4=CC=C(Cl)C=C4)=O)CC5=CC=CN=C5)=O)CO)=O)C)CC6=CC=C(O)C=C6)=O)CC(N)=O

Appearance: Solid powder

Purity: >98% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: Soluble in DMSO, not in water

Shelf Life: >2 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Preparing Stock Solutions

The following data is based on the product molecular weight 1416.06 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Tombal B. New treatment paradigm for prostate cancer: abarelix initiation therapy for immediate testosterone suppression followed by a luteinizing hormone-releasing hormone agonist. BJU Int. 2012 Mar;109(6):E16; author reply E16-7. doi: 10.1111/j.1464-410X.2012.10983.x. PubMed PMID: 22360806.

2: Garnick MB, Mottet N. New treatment paradigm for prostate cancer: abarelix initiation therapy for immediate testosterone suppression followed by a luteinizing hormone-releasing hormone agonist. BJU Int. 2012 Aug;110(4):499-504. doi: 10.1111/j.1464-410X.2011.10708.x. Epub 2011 Nov 16. PubMed PMID: 22093775.

3: Koechling W, Hjortkjaer R, Tankó LB. Degarelix, a novel GnRH antagonist, causes minimal histamine release compared with cetrorelix, abarelix and ganirelix in an ex vivo model of human skin samples. Br J Clin Pharmacol. 2010 Oct;70(4):580-7. doi: 10.1111/j.1365-2125.2010.03730.x. PubMed PMID: 20840449; PubMed Central PMCID: PMC2950992.

4: Retraction statement: Reconstitution of Plenaxis® (Abarelix) 100 mg for injection is more effective with a vortex-like mixer than when performed manually. J Pharm Pract. 2010 Feb;23(1):78. doi: 10.1177/0897190009360369. PubMed PMID: 21507797.

5: Kirby RS, Fitzpatrick JM, Clarke N. Abarelix and other gonadotrophin-releasing hormone antagonists in prostate cancer. BJU Int. 2009 Dec;104(11):1580-4. doi: 10.1111/j.1464-410X.2009.08924.x. Review. PubMed PMID: 20053189.

6: Debruyne F, Bhat G, Garnick MB. Abarelix for injectable suspension: first-in-class gonadotropin-releasing hormone antagonist for prostate cancer. Future Oncol. 2006 Dec;2(6):677-96. Review. PubMed PMID: 17155895.

7: Beer TM, Ryan C, Bhat G, Garnick M; Abarelix Study Group. Dose-escalated abarelix in androgen-independent prostate cancer: a phase I study. Anticancer Drugs. 2006 Oct;17(9):1075-9. PubMed PMID: 17001181.

8: Hogle WP. Abarelix (plenaxis). Clin J Oncol Nurs. 2004 Dec;8(6):663-5. PubMed PMID: 15637961.

9: Mongiat-Artus P, Teillac P. Abarelix: the first gonadotrophin-releasing hormone antagonist for the treatment of prostate cancer. Expert Opin Pharmacother. 2004 Oct;5(10):2171-9. Review. PubMed PMID: 15461552.

10: Wong SL, Lau DT, Baughman SA, Fotheringham N, Menchaca D, Garnick MB. Pharmacokinetics and pharmacodynamics of a novel depot formulation of abarelix, a gonadotropin-releasing hormone (GnRH) antagonist, in healthy men ages 50 to 75. J Clin Pharmacol. 2004 May;44(5):495-502. PubMed PMID: 15102870.

Additional Information

Abarelix (trade name Plenaxis) is an injectable gonadotropin-releasing hormone antagonist (GnRH antagonist). It is primarily used in oncology to reduce the amount of testosterone made in patients with advanced symptomatic prostate cancer for which no other treatment options are available. It was originally marketed by Praecis Pharmaceuticals as Plenaxis, and is now marketed by Speciality European Pharma in Germany after receiving a marketing authorisation in 2005. (source: http://en.wikipedia.org/wiki/Abarelix).