Targeted delivery for breast cancer therapy: the history of nanoparticle-albumin-bound paclitaxel

IMPORTANCE OF THE FIELD

Taxanes are agents for the treatment of breast cancer. Paclitaxel is hydrophobic, and available formulations require polyoxyethylated castor oil, Cremphor EL (CrEL) and an ethanol vehicle to allow parental administration. Nanoparticle albumin-bound paclitaxel (nab-P) is a CrEL-free formulation of paclitaxel. The human albumin-stabilized paclitaxel particles have a size of approximately 130 nm, which allows intravenous infusion without capillary blockage.

AREAS COVERED IN THIS REVIEW

Efficacy and safety of nab-P in breast cancer has been compared with paclitaxel and docetaxel in large Phase III and II trials. Additionally, the efficacy and safety of nab-P have been investigated in other single-arm clinical trials, in early and advanced disease.

WHAT THE READER WILL GAIN

Preclinical and clinical development of the drug across all clinical trials published so far, the approved clinical indications, the benefits of this taxane formulation and a look into the future with emphasis on the application in specific subtypes of breast cancer.

TAKE HOME MESSAGE

nab-P has been approved for the treatment of metastatic breast cancer in patients who have failed first-line treatment for metastatic disease and for whom standard, anthracycline-containing therapy is not indicated and represents one of most authoritative and sophisticated applications of nanotechnology in cancer treatment so far.

Microtubule active agents: beyond the taxane frontier

Microtubules are essential to cell transport, signaling, and mitosis. An increasing range of anticancer drugs interferes with the normal formation and function of microtubules. Vinca alkaloids act as microtubule destabilizers and the taxanes act as microtubule stabilizers. Taxanes are widely used cytotoxic agents that are active in a range of solid tumor malignancies and are routinely used in a variety of settings. Significant limitations with the taxanes exist, including acquired and intrinsic tumor resistance through the expression of multidrug resistance proteins such as P-glycoprotein, risk of hypersensitivity reactions, dose-limiting hematopoietic toxicity, and cumulative neurotoxicity. Hence, there is a need to develop novel agents that act on the microtubules. Epothilones are macrolide antibiotics that bind near the taxane-binding site on microtubules and have been extensively studied in recent and ongoing clinical trials. A variety of other agents that act on the microtubules at different sites with a variety of structures are at varying stages of development.