Mechanism of Action

IXEMPRA® (ixabepilone) is a non-taxane microtubule-targeting agent1

In preclinical studies, IXEMPRA, a semisynthetic analog of epothilone B, had low susceptibility to multiple mechanisms of resistance1-4,*

  • IXEMPRA binds directly to beta-tubulin subunits and suppresses their dynamic instability, blocking the mitotic phase of the cell division cycle and inducing cell death1
  • IXEMPRA has antitumor activity in vivo against multiple human tumor xenografts, including drug-resistant types that1:
    • Harbor tubulin mutations
    • Overexpress efflux transporters such as P-gp and MRP1
    • Overexpress beta-III tubulin isoforms
  • IXEMPRA is also active in xenografts resistant to multiple agents, including taxanes, anthracyclines, and vinca alkaloids1
  • IXEMPRA works synergistically with capecitabine and possesses anti-angiogenic activity1
* The clinical significance of this has not been determined.

IXEMPRA mechanism of action1,2

References: 1. IXEMPRA (ixabepilone) Prescribing Information; January 2016. 2. Vahdat L. Ixabepilone: a novel antineoplastic agent with low susceptibility to multiple tumor resistance mechanisms. Oncologist. 2008;13(3):214-221. 3. Shen H, Lee FY, Gan J. Ixabepilone, a novel microtubule-targeting agent for breast cancer, is a substrate for P-glycoprotein (P-gp/MDR1/ABCB1) but not breast cancer resistance protein (BCRP/ABCG2). J Pharmacol Exp Ther. 2011;337(2):423-432. 4. Dumontet C, Jordan MA, Lee FFY. Ixabepilone: targeting βIII-tubulin expression in taxane-resistant malignancies. Mol Cancer Ther. 2009;8(1):17-25.

Indications and Important Safety Informationexpand

Important Safety Information

IXEMPRA is contraindicated in patients:


Toxicity in patients with hepatic impairment

Peripheral neuropathy


Hypersensitivity reactions

Cardiac adverse reactions


Alcohol Content


Adverse reactions


Combination with capecitabine

Cremophor is a registered trademark of BASF AG.
AST = aspartate aminotransferase; ALT = alanine aminotransferase; ULN = upper limit of normal; CTC = common terminology criteria.


IXEMPRA® (ixabepilone) is indicated for treatment in combination with capecitabine for patients with metastatic or locally advanced breast cancer resistant to treatment with an anthracycline and a taxane, or whose cancer is taxane resistant and for whom further anthracycline therapy is contraindicated.

IXEMPRA is indicated for treatment as a single agent for patients with metastatic or locally advanced breast cancer after failure of an anthracyclines, taxanes, and capecitabine.

Please see US Full Prescribing Information, including boxed WARNING regarding hepatic impairment.


Medical information

For product information or to report an adverse reaction, please call 1-844-586-8953 or e mail

This site is intended for US healthcare professionals.

The R-Pharm US Access and Support logo is a trademark and IXEMPRA® is a registered trademark of R-Pharm US Operating LLC, a wholly-owned subsidiary of R-Pharm US LLC.

© 2024, R-PHARM US. All rights reserved. IXE-00096-02   08/16