Efficacy and safety of nab-paclitaxel 125 mg/m2 and nab-paclitaxel 150 mg/m2 compared to paclitaxel in early high-risk breast cancer. Results from the neoadjuvant randomized GeparSepto study (GBG 69)

PURPOSE

The GeparSepto study demonstrated that the use of nab-paclitaxel instead of paclitaxel prior to anthracycline-based chemotherapy could lead to a significantly increased pCR rate, especially in the triple negative subpopulation. We report efficacy and safety for patients treated with two different doses of nab-paclitaxel in comparison to weekly solvent-formulated paclitaxel.

METHODS

Patients were treated for 12 weeks with either intravenous nab-paclitaxel 150 mg/m² (nP150) weekly, after study amendment 125 mg/m² (nP125) weekly or solvent-based paclitaxel 80 mg/m² (P80) weekly followed by epirubicin 90 mg/m² and cyclophosphamide 600 mg/m² on day 1 for four 3-week cycles.

RESULTS

229 patients received nP150, 377 nP125. Baseline characteristics were fairly balanced between these two sequential cohorts as well as compared to 601 patients receiving P80 except for hormone receptor status, HER2 status, and Ki67. Taxane treatment was discontinued in 26.8% (nP150), 16.6% (nP125), and 13.3% of (P80) patients, respectively. Median relative total dose intensity (mRTDI) based on 125 mg/m² for nP was 103% with nP150, 95% with nP125, 99% with P80 before and 98% with P80 after the amendment. PSN grade 3-4 was observed in 14.5% of patients with nP150, 8.1% of patients with nP125 (p = 0.018), and 2.7% of patients with P80. Overall pCR before the amendment was 33.6% after nP150 and 23.5% after P80 (OR 1.65 [95% CI 1.10-2.50]; p = 0.022); pCR after the amendment was 41.4% after nP125, and 32.4% after P80 (1.48 [95% CI 1.10-1.99]; p = 0.013).

CONCLUSIONS

Nab-paclitaxel 125 mg/m² was associated with a better safety profile and compliance without compromising the efficacy compared to nab-paclitaxel 150 mg/m².

Neoadjuvant nab-paclitaxel in the treatment of breast cancer

Neoadjuvant chemotherapy has the advantage of converting unresectable breast tumors to resectable tumors and allowing more conservative surgery in some mastectomy candidates. Chemotherapy agents, including taxanes, which are recommended in the adjuvant setting, are also considered in the neoadjuvant setting. Here, we review studies of nab-paclitaxel as a neoadjuvant treatment for patients with breast cancer. PubMed and conference or congress proceedings were searched for clinical studies of nab-paclitaxel in the neoadjuvant treatment of breast cancer. We also searched ClinicalTrials.gov for ongoing trials of nab-paclitaxel as a neoadjuvant agent in breast cancer. Twenty studies of nab-paclitaxel in the neoadjuvant setting were identified. In addition to reviewing key efficacy and safety data, we discuss how each trial assessed response, focusing on pathologic complete response and residual cancer burden scoring. Safety profiles are also reviewed. nab-Paclitaxel demonstrated antitumor activity and an acceptable safety profile in the neoadjuvant treatment of breast cancer. Ongoing and future trials will further evaluate preoperative nab-paclitaxel in breast cancer, including in combination with many novel immunological targeted therapies.

The value of platinum agents as neoadjuvant chemotherapy in triple-negative breast cancers: a systematic review and meta-analysis

Platinum agents such as cisplatin and carboplatin are DNA-damaging agents with activity in breast cancer (BC), particularly in the triple negative (TN) subgroup. The utility of platinum agents, in addition to standard neoadjuvant chemotherapy (NAC), is controversial. To assess the activity of platinum agents in patients with TNBC treated with NAC, we performed a systematic review and meta-analysis of all published studies. A search of PubMed, EMBASE, the Web of Science, SCOPUS, and the Cochrane Central Register of Controlled Trials was performed to identify studies that investigated platinum-based NAC in patients with TNBC. Random effect models were adopted to estimate the summary risk ratio (RR), and the publication bias was evaluated using a funnel plot and Egger's regression asymmetry test. The primary endpoints were the pooled rate of the pathologic complete response (pCR) and the RR to obtain a pCR in patients treated versus not treated with NAC containing platinum agents. 28 studies were included (six randomized controlled trials and 22 retrospective or prospective studies) for a total of 1,598 TNBC patients. Overall, the pooled rate of pCR in patients treated with platinum-based NAC was 45 %. In randomized trials, NAC containing cisplatin or carboplatin significantly increased the rate of pCR compared with nonplatinum agents (RR = 1.45, 95 % CI 1.25-1.68; P < 0.0001). Compared with non-TN, TNBCs were associated with a threefold increase in the pCR rate when treated with platinum-based NAC (RR 3.32, 95 % CI 2.39-4.61; P < 0.0001). In conclusion, pCR rates increase significantly with the addition of cisplatin or carboplatin in TNBC compared with NAC containing no platinum drugs. TN status is a predictor of benefit from platinum-based NAC.

Targeted therapies in colorectal cancer-an integrative view by PPPM

In developed countries, colorectal cancer (CRC) is the third most common malignancy, but it is the second most frequent cause of cancer-related death. Clinicians are still faced with numerous challenges in the treatment of this disease, and future approaches which target the molecular features of the disorder will be critical for success in this disease setting. Genetic analyses of many solid tumours have shown that up to 100 protein-encoding genes are mutated. Within CRC, numerous genetic alterations have been identified in a number of pathways. Therefore, understanding the molecular pathology of CRC may present information on potential routes for treatment and may also provide valuable prognostic information. This will be particularly pertinent for molecularly targeted treatments, such as anti-vascular endothelial growth factor therapies and anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy. KRAS and BRAF mutations have been shown to predict response to anti-EGFR therapy. As EGFR can also signal via the phosphatidylinositol 3-kinase (PI3K) kinase pathway, there is considerable interest in the potential roles of members of this pathway (such as PI3K and PTEN) in predicting treatment response. Therefore, a combined approach of new techniques that allow identification of these biomarkers alongside interdisciplinary approaches to the treatment of advanced CRC will aid in the treatment decision-making process and may also serve to guide future therapeutic approaches.

Patients with metastatic breast cancer using bevacizumab as a treatment: is there still a role for it?

OPINION STATEMENT

Over the last few decades, the angiogenesis mechanism has increasingly been studied and implicated in cancer pathophysiology. At present, it is known that angiogenesis plays a relevant role in tumor growth, and more importantly many new molecules exists can potentially interfere with this process. Bevacizumab, a humanized monoclonal antibody targeting the vascular endothelial growth factor A (VEGF-A) now commonly used in the treatment of colorectal, renal cell, and brain cancer, is the first anti-angiogenesis drug delivered in combination with chemotherapy that has consistently shown clinical efficacy in the treatment of breast cancer. Since the ECOG 2100 trial has shown that bevacizumab added to paclitaxel as a first-line treatment for advanced breast cancer nearly doubled the time to progression and tumor response rate, its approval was granted almost worldwide. However, other phase III trials revealed a smaller absolute improvement in progression-free survival (PFS) and response rates, and no trials yet have demonstrated survival enhancement which led to a great controversy and debate over the use of bevacizumab. The discrepancy between PFS and overall survival also raises the question of whether or not bevacizumab has been applied sub-optimally in some of the studies, if a predictive biomarker(s) exists to select the group of patients whom would receive the greatest benefit and what is the appropriate clinical end-point for approval and funding of new targeted agents. In this article we will review the bevacizumab mechanism of action and the clinical trials that assessed its benefit in the treatment of metastatic breast cancer (MBC).

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.