Biosimilars are similar, but non-identical, versions of existing biological drugs for which patents have expired. Despite the rigorous approval process for biosimilars, concerns have been expressed about the efficacy and safety of these products in clinical practice. Biosimilars of filgrastim, based on the originator product Neupogen®, have been available since 2008 and are now in widespread clinical use in Europe and elsewhere. Three biosimilar G-CSFs have been approved based on a combination of physicochemical and biological protein characterisation, pharmacokinetic and pharmacodynamic assessment in healthy volunteers and efficacy and safety data in patients with cancer. To assess whether biosimilars are effective in the real-world clinical practice setting, a pooled analysis of five post-approval studies of biosimilar G-CSF (Zarzio®) that included 1,302 adult patients who received at least one cycle of chemotherapy with G-CSF support for the prevention of neutropenia was conducted. A total of 36 % of patients had a febrile neutropenia risk of >20 %, while 39.6 % had a risk of 10–20 % based on chemotherapy regimen. The occurrence of severe or febrile neutropenia was within the range of that observed in previous studies of originator G-CSF. In addition, the safety profile of Zarzio® was consistent with that reported for originator G-CSF and the known safety profile of G-CSF. Initial concerns about the use of biosimilars, at least with regard to biosimilar G-CSFs, appear to be unfounded. Adoption of cost-effective biosimilars should help reduce healthcare costs and improve patient access to biological treatments.

Background: To evaluate the modifications of circulating angiogenic factors, metalloproteinases and acute-phase cytokines after the first single zoledronic acid (ZA) intravenous infusion. Experimental Design:Eighteen consecutive breast cancer patients with bone metastases were evaluated for circulating levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), metalloproteinase 1 (MMP-1), metalloproteinase 2 (MMP-2), interleukins 1β, 6 and 8 (IL-1β, IL-6, IL-8), interferon γ, tumor necrosis factor α (TNF-α) and transforming growth factor β₁ just before and 2 and 7 days after ZA infusion. Results: The MMP-2 basal value showed a statisticallysignificant decrease 48 h after ZA (p = 0.01), being at 7 days higher than the day 2 value (p = 0.03). The VEGF basal value showed a statisticallysignificant decrease 48 h after ZA infusion (p = 0.03), increasing above the basal level at 7 days (p = 0.07). The bFGF basal level almost significantly decreased 2 days after infusion (p = 0.06), being at 7 days higher than the basal value (p = 0.09). Comparing the day 2 values with basal ones, the linear regression model showed a significantpositive correlation between IL-8 and bFGF (p = 0.02), IL-8 and TNF-α (p < 0.0001), bFGF and TNF-α (p = 0.01), MMP-1 and TNF-α (p = 0.02). Conclusions: ZA could exert an antiangiogenic activity and inhibition of tumor cell bone invasiveness by a transient reduction of VEGF, bFGF and MMP-2 circulating levels after infusion.

Background: Eribulin was recently approved in patients progressing after being treated with anthracyclines and taxanes and after two or more chemotherapy lines for advanced disease.Objectives: This multicenter observational retrospective study was performed in order to evaluate activity and tolerability of eribulin in real-world patient population.Methods: 133 advanced breast cancer patients pretreated with ≥ 2 chemotherapy lines for metastatic disease were retrospectively enrolled in the observational trial in 11 italian cancer centres.Results: A median of 5 cycles of eribulin (range, 1-15) were administered. Twenty-eight partial responses were observed, for an overall response rate of 21.1% (95%CI,14.1-28.0). A stable disease was recorded in 57 patients (42.8%), and a clinical benefit (response or stable disease lasting ≥ six months) was observed in 51 patients (38.3%, 95%CI, 30.1-46.6). The subgroup analysis showed that a significant improvement in term of partial response and clinical benefit was achieved when eribulin was administered in HER-2 negative tumors (p=0.01 and p=0.004, respectively) and when it is given as third-line (p=0.09 and p=0.02, respectively). Toxicity was manageable; fatigue is the most common side effect observed, usually of low-grade, and clearly cumulative-dose related.Conclusions: In this retrospective, observational analysis eribulin confirmed its efficacy and manageable tolerability even in real-world population and in heavily pretreated patients.

Hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer is the most common breast cancer subtype, and endocrine therapy (ET) remains its therapeutic backbone. Although anti-estrogen therapies are usually effective initially, approximately 50% of HR+ patients develop resistance to ET within their lifetime, ultimately leading to disease recurrence and limited clinical benefit. The recent addition of cyclin-dependent kinase 4 (CDK4) and CDK6 inhibitors (palbociclib, ribociclib, abemaciclib) to ET have remarkably improved the outcome of patients with HR+ advanced breast cancer (ABC) compared with anti-estrogens alone, by targeting the cell-cycle machinery and overcoming some aspects of endocrine resistance. However, which patients are the better candidates for these drugs, which are the main characteristics for a better selection of patients or if there are predictive biomarkers of response, is still unknown. In this review we reported the mechanism of action of CDK4/6 inhibitors as well as their potential mechanism of resistance, their implications in clinical practice and the forthcoming strategies to enhance their efficacy in improving survival and quality of life of patients affected with HR+, HER2−, ABC.

Our study confirms the effectiveness of eribulin mesylate in the treatment of patients with metastatic breast cancer and two or more lines of chemotherapy, in particular in the good disease control at the different metastatic sites.