Nanoparticle-Based Combination Therapy Enhances Fulvestrant Efficacy and Overcomes Tumor Resistance in ER-Positive Breast Cancer.

Abstract

Nanoparticles (NP) spanning diverse materials and properties have the potential to encapsulate and to protect a wide range of therapeutic cargos to increase bioavailability, to prevent undesired degradation, and to mitigate toxicity. Fulvestrant, a selective estrogen receptor degrader, is commonly used for treating patients with estrogen receptor (ER)-positive breast cancer, but its broad and continual application is limited by poor solubility, invasive muscle administration, and drug resistance. Here, we developed an active targeting motif-modified, intravenously injectable, hydrophilic NP that encapsulates fulvestrant to facilitate its delivery via the bloodstream to tumors, improving bioavailability and systemic tolerability. In addition, the NP was coloaded with abemaciclib, an inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), to prevent the development of drug resistance associated with long-term fulvestrant treatment. Targeting peptide modifications on the NP surface assisted in the site-specific release of the drugs to ensure specific toxicity in the tumor tissues and to spare normal tissue. The NP formulation (PPFA-cRGD) exhibited efficient tumor cell killing in both in vitro organoid models and in vivo orthotopic ER-positive breast cancer models without apparent adverse effects, as verified in mouse and Bama miniature pig models. This NP-based therapeutic provides an opportunity for continual and extensive clinical application of fulvestrant, thus indicating its promise as a treatment option for patients with ER-positive breast cancer.

SIGNIFICANCE:

A smart nanomedicine encapsulating fulvestrant to improve its half-life, bioavailability, and tumor-targeting and coloaded with CDK4/6 inhibitor abemaciclib to block resistance is a safe and effective therapy for ER-positive breast cancer.

• Authors: Bozhao Li, Feilong Qi, Fei Zhu, Zefang Lu, Meiqi Wang, Tianjiao Chu, Suying Wu, Jingyan Wei, Zhenchuan Song, Saraswati Sukumar, Cheng Zhang, Jiangfei Xu, Suping Li, Guangjun Nie
• Journal: Cancer research (Cancer Res) Vol. 83 Issue 17 Pg. 2924-2937 (09 01 2023) ISSN: 1538-7445 [Electronic] United States
• PMID: 37326467 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: ©2023 American Association for Cancer Research.

Chemical References

• Fulvestrant
• abemaciclib
• Receptors, Estrogen
• Aminopyridines

Topics

• Animals
• Mice
• Swine
• Fulvestrant (pharmacology, therapeutic use)
• Receptors, Estrogen (metabolism)
• Aminopyridines (pharmacology)
• Neoplasms (drug therapy)
• Drug Resistance, Neoplasm
• Cell Line, Tumor