Albumin-Bound Formulations

Albumin-bound formulations
Abraxane was the first albumin-bound chemotherapeutic agent to get FDA approval. It contained PTX (a taxane) non-covalently bound to nano-albumin (nab), and was prepared by homogenization of PTX in association with human serum albumin. Multiple PTX molecules (hydrophobic in nature) were bound to each nab. Preclinical studies (in rats) showed equivalent efficacy and improved safety when compared with Taxol (PTX formulation in Cremophor solvent). Clinical trials of Abraxane comparing to Taxol, showed a tolerable dose 50% larger than Taxol and improved tumor response in patients. Abraxane got approval for breast cancer and; later in 2012 and 2013; it was approved for Non-Small Cell Lung Cancer (NSCLC) and pancreatic carcinoma, respectively [82].

Working on the success of Abraxane, nab-rapamycin was also prepared. Rapamycin (also known as sirolimus) works by inhibiting the signals from intracellular kinase (mTOR) which further inhibits cell proliferation. Rapamycin also had poor solubility similar to PTX hence, nab rapamycin was prepared to overcome this barrier and increase its efficacy. The nanoformulation proved to be efficacious in preclinical studies (breast tumor xenograft model) and the drug (ABI-009) is undergoing Phase I-III trials in humans for multiple carcinomas including advanced sarcoma, advanced malignant perivascular epithelioid cell tumor, non muscle invasive bladder cancer and recurrent or refractory solid tumors [82,