Current trends in the use of human serum albumin for drug delivery in cancer

INTRODUCTION

Human serum albumin is the most abundant transport protein in plasma, which has recently been extensively utilized to form nanoparticles for drug delivery in cancer. The primary reason for selecting albumin protein as drug delivery cargo is its excellent biocompatibility, biodegradability, and non-immunogenicity. Moreover, the albumin structure containing three homologous domains constituted of a single polypeptide (585 amino acid) incorporates various hydrophobic drugs by non-covalent interactions. Albumin shows active tumor targeting via their interaction with gp60 and SPARC proteins abundant in the tumor-associated endothelial cells and the tumor microenvironment.

AREAS COVERED

The review discusses the importance of albumin as a drug-carrier system, general procedures to prepare albumin NPs, and the current trends in using albumin-based nanomedicines to deliver various chemotherapeutic agents. The various applications of albumin in the nanomedicines, such as NPs surface modifier and fabrication of hybrid/active-tumor targeted NPs, are delineated based on current trends.

EXPERT OPINION

Nanomedicines have the potential to revolutionize cancer treatment. However, clinical translation is limited majorly due to the lack of suitable nanomaterials offering systemic stability, optimum drug encapsulation, tumor-targeted delivery, sustained drug release, and biocompatibility. The potential of albumin could be explored in nanomedicines fabrication for superior treatment outcomes in cancer.

Nab-paclitaxel/bevacizumab/carboplatin chemotherapy in first-line triple negative metastatic breast cancer

BACKGROUND

Triple negative metastatic breast cancer can be difficult to treat with primarily cytotoxic options. Nab-paclitaxel has demonstrated improved PFS and tolerability compared with standard cremophor-solubilized paclitaxel; based on this, we examined the efficacy and safety of combining weekly nab-paclitaxel with carboplatin and bevacizumab in TNMBC.

PATIENTS AND METHODS

In this phase II, multicenter trial, patients with first-line TNMBC received nab-paclitaxel (100 mg/m(2)) and carboplatin (area under the curve = 2) on days 1, 8, 15, and bevacizumab (10 mg/kg) on days 1 and 15 of a 28-day cycle. The primary end point was safety and tolerability and secondary end points included PFS, ORR, and CBR. PFS was calculated using the Kaplan-Meier method.

RESULTS

Between July 16, 2007, and October 3, 2011, 34 patients were enrolled at 4 centers. Median age was 50.0 (range, 30-76) years and 77% (n = 26) of patients received previous adjuvant therapy. Median PFS was 9.2 months (95% confidence interval [CI], 7.8-25.1 months). The CBR was 94% (95% CI, 80%-99%), and ORR was 85% (95% CI, 69%-95%) for the combination. The regimen was well tolerated with the most common grade 3/4 adverse events being neutropenia (n = 18; 53%) and thrombocytopenia (n = 6; 18%), with other serous events including 1 grade 3 and 1 grade 4 thrombotic event and 1 febrile neutropenia.

CONCLUSION

The combination of nab-paclitaxel, bevacizumab, and carboplatin as first-line treatment for TNMBC was efficacious and well tolerated. The PFS, CBR, and ORR, and tolerability of the regimen, compares favorably with other standard first-line therapies.

Weekly nab-Paclitaxel in Metastatic Breast Cancer - Summary and Results of an Expert Panel Discussion

Taxanes are regarded as the most effective single agents in the treatment of metastatic breast cancer (MBC). For conventional taxanes, crucial toxicities and impairments in clinical efficacy are related to solvents necessary because of the agents' hydrophobicity. The mandatory premedication with corticosteroids causes additional side effects. Nab-paclitaxel is a solvent-free colloidal suspension of paclitaxel and human serum albumin that exploits the physiological transport properties of albumin. It is registered as monotherapy with a recommended dose of 260 mg/m(2) every 3 weeks for the treatment of patients with MBC, who have failed a first-line treatment of metastatic disease and for whom a standard anthracycline treatment is not indicated. Clinical evidence is available for the registered 3-weekly administration and for alternative weekly schedules in first and further lines of therapy of patients with MBC. During an advisory board meeting, a group of 8 German breast cancer experts reviewed the clinical data of nab-paclitaxel in MBC and discussed how nab-paclitaxel could be used in clinical practice on the basis of the current data.

Management of breast cancer with nanoparticle albumin-bound (nab)-paclitaxel combination regimens: a clinical review

BACKGROUND

Monotherapy with nanoparticle albumin-bound (nab)-paclitaxel has demonstrated improved efficacy and safety compared with solvent-based paclitaxel and docetaxel.

DESIGN

A comprehensive review of all reported studies of nab-paclitaxel combinations with other agents in all breast cancer settings was undertaken.

RESULTS

Most studies reviewed are small, phase II and non-comparative. Combinations studied included nab-paclitaxel plus trastuzumab and/or bevacizumab (with or without additional cytotoxic agents), gemcitabine, capecitabine, carboplatin, or lapatinib. The majority of metastatic and neoadjuvant studies demonstrated satisfactory efficacy and safety for nab-paclitaxel combinations, although conclusions regarding comparison with solvent-based taxane (SBT) regimens are not possible. The two adjuvant studies confirmed the safety of nab-paclitaxel combinations in this setting.

CONCLUSIONS

Although results of this review indicate that nab-paclitaxel may be an appropriate substitute for SBTs in combination regimens, additional research is required to confirm the place and cost effectiveness of these combinations before nab-paclitaxel could be recommended routinely in all settings.

Antiangiogenic therapy for breast cancer

Angiogenesis is an important component of cancer growth, invasion and metastasis. Therefore, inhibition of angiogenesis is an attractive strategy for treatment of cancer. We describe existing clinical trials of antiangiogenic agents and the challenges facing the clinical development and optimal use of these agents for the treatment of breast cancer. Currently, the most promising approach has been the use of bevacizumab, a humanized monoclonal antibody directed against the most potent pro-angiogenic factor, vascular endothelial growth factor (VEGF). Small molecular inhibitors of VEGF tyrosine kinase activity, such as sorafenib, appear promising. While, the role of sunitinib and inhibitors of mammalian target of rapamycin (mTOR) in breast cancer has to be defined. Several unanswered questions remain, such as choice of drug(s), optimal duration of therapy and patient selection criteria.

Bevacizumab in the treatment of patients with advanced breast cancer: where have we landed?

Vast preclinical and clinical evidence has made angiogenesis one of the hallmarks of cancer. In many human tumours, vascular endothelial growth factor (VEGF) has been identified as the crucial mediator of this process. Initial studies suggested that angiogenesis, and VEGF in particular, could be inhibited without the risk of major side effects. After the pivotal data in first-line studies in patients with colorectal cancer, numerous clinical trials have been undertaken in patients with breast cancer. This review attempts to update these investigations and define the role of anti-VEGF antibody treatment in advanced breast cancer.

The expanding role of bevacizumab in the treatment of human epidermal growth factor receptor 2-negative breast cancer

A growing body of evidence consistently demonstrates the activity of bevacizumab, a monoclonal antibody that targets all isoforms of vascular endothelial growth factor (VEGF)-A, in combination with chemotherapy in the treatment of patients with human epidermal growth factor receptor 2 (HER2)-negative, metastatic breast cancer. Clinical benefit has been limited to prolonged progression-free survival. As yet, combination regimens have failed to demonstrate a survival advantage. Emerging research suggests that single-nucleotide polymorphism in VEGF may predict response to combined therapy.