Results of Two Open-Label, Multicenter Phase II Studies of Docetaxel, Platinum Salts, and Trastuzumab in HER2-Positive Advanced Breast Cancer

Tailoring Neoadjuvant Therapy in Human Epidermal Growth Factor Receptor 2-Positive Early Breast Cancer: Recent Advances and Strategies

Neoadjuvant HER2 Therapy: Beyond one-size-fits-all.

Phase I study of LZM005 in patients with HER2-positive metastatic breast cancer

The prognosis of human epidermal growth factor receptor 2 (HER2) positive metastatic breast cancer (MBC) remained unsatisfactory currently, more anti-HER2 agents are needed. Here we report a phase I study that evaluated the safety, activity, and biomarkers of LZM005, a HER2 antibody, used as a monotherapy or in combination with trastuzumab plus docetaxel in patients with HER2-positive MBC. From October 2017 to December 2019, 34 patients received LZM005 (14 monotherapy, 20 combination therapy). No DLT was observed. The common adverse events (AEs) in phase Ia included diarrhea (21.4%), infusion reaction (21.4%), and hypertriglyceridemia (21.4%), while those in phase Ib were leukopenia (85.0%), neutropenia (75.0%), anemia (60.0%), diarrhea (60.0%), and rash/pruritus (50.0%). All AEs were manageable. In phase Ia, partial response (PR) was achieved in one case (1/14, overall response rate [ORR]: 7.1%); the disease control rate was 42.90% (6/14). In phase Ib, 11 patients (55.0%) achieved PR, and eight (40.0%) had stable disease. The ORR was 100% (6/6) in trastuzumab-naive and 35.7% (5/14) in trastuzumab-pretreated patients. Biomarker analysis showed that chromatin remodeling genes KMT2B and BRWD1 were associated with better progression-free survival. LZM005 is well tolerated and shows potent activity in patients with HER2-positive MBC.

Anti-HER2 monoclonal antibodies intensify the susceptibility of human gastric cancer cells to etoposide by promoting apoptosis, but not autophagy

BACKGROUND

Gastric cancer (GC) is a multifactorial disease with high mortality. Anti-HER2 therapy is a promising strategy in GC treatment and trastuzumab was approved by FDA (Food and Drug Administration) as the first and the second line of treatment of the disease.

PURPOSE

The aim of the study was to examine the effectiveness of a combination of etoposide with trastuzumab or pertuzumab in AGS gastric cancer cells and breast cancer cells such as MCF-7, MDA-MB-231 and HCC1954.

METHODS AND FINDINGS

The cytotoxic effects of the tested compounds against gastric and breast cancer cells were checked by MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) assay. The anti-proliferative potential was analyzed by the incorporation of [3H]-thymidine into DNA. Fluorescent microscopy and flow cytometry was used to demonstrate the effect of the compounds on apoptosis. The mitochondrial membrane potential, and the activity of caspase-8 and caspase-9 were assessed. Autophagosomes and autolysosomes formation was checked by flow cytometry. The concentrations of Beclin-1, LC3A and LC3B were performed using ELISA. The expression of LC3A/B was also determined. The results from our study proved that the combination of etoposide with anti-HER2 antibodies was not cytotoxic against breast cancer cells, whereas the combination of etoposide with anti-HER2 antibodies decreased viability and DNA biosynthesis in gastric cancer cells. The interaction of etoposide with pertuzumab or trastuzumab induced programmed cell death via extrinsic and intrinsic apoptotic pathways in AGS gastric cancer cells, but did not affect autophagy, where a decrease of Beclin-1, LC3A and LC3B was observed in comparison with the untreated control.

CONCLUSIONS

The study demonstrated that etoposide (12.5 μM) with pertuzumab represent a promising strategy in gastric cancer treatment, but further in vivo examinations are also required.

Targeting mTOR and Glycolysis in HER2-Positive Breast Cancer

Up to one third of all breast cancers are classified as the aggressive HER2-positive subtype, which is associated with a higher risk of recurrence compared to HER2-negative breast cancers. The HER2 hyperactivity associated with this subtype drives tumor growth by up-regulation of mechanistic target of rapamycin (mTOR) pathway activity and a metabolic shift to glycolysis. Although inhibitors targeting the HER2 receptor have been successful in treating HER2-positive breast cancer, anti-HER2 therapy is associated with a high risk of recurrence and drug resistance due to stimulation of the PI3K-Akt-mTOR signaling pathway and glycolysis. Combination therapies against HER2 with inhibition of mTOR improve clinical outcomes compared to HER2 inhibition alone. Here, we review the role of the HER2 receptor, mTOR pathway, and glycolysis in HER2-positive breast cancer, along with signaling mechanisms and the efficacy of treatment strategies of HER2-positive breast cancer.

Nanosomal Docetaxel Lipid Suspension-Based Chemotherapy in Breast Cancer: Results from a Multicenter Retrospective Study

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of nanosomal docetaxel lipid suspension (NDLS, DoceAqualip)-based chemotherapy in breast cancer.

METHODS

Medical charts of patients with breast cancer, who were treated and followed up with NDLS (75-100 mg/m2; 3-week cycle)-based chemotherapy from August 2014 to September 2018, were analyzed in this multicenter, retrospective study. The study endpoints were overall response rate (ORR: complete response [CR]+partial response [PR]) and disease control rate (DCR: CR+PR+stable disease [SD]) in neoadjuvant and metastatic settings. Overall survival (OS) and safety were evaluated for all settings.

RESULTS

Of 91 patients (neoadjuvant: 12, adjuvant: 61, metastatic: 18), efficacy evaluation in 29 patients (neoadjuvant: 12/12, metastatic: 17/18) demonstrated an ORR and DCR of 100%, respectively, in the neoadjuvant setting, and an ORR of 64.7% and DCR of 70.6%, respectively, in the metastatic setting. At a median follow-up of 21.6 months (range: 2.1 to 49.9 months), median OS was not reached in neoadjuvant and adjuvant settings, and it was 30.4 months in metastatic settings. At least one adverse event (AE) was reported in 59.3% of patients. Anemia, thrombocytopenia, lymphopenia, and neutropenia were the most common hematological AEs reported while hyperglycemia and alteration in liver function tests were the most common non-hematological AEs. NDLS-based treatment was well tolerated without any new safety concerns.

CONCLUSION

Nanosomal docetaxel lipid suspension-based chemotherapy was efficacious and well tolerated in the treatment of breast cancer. Further, NDLS is being evaluated prospectively in patients with triple-negative breast cancer (ClinicalTrials.gov: NCT03671044).

Hydrodynamic and Electrophoretic Properties of Trastuzumab/HER2 Extracellular Domain Complexes as Revealed by Experimental Techniques and Computational Simulations

The combination of hydrodynamic and electrophoretic experiments and computer simulations is a powerful approach to study the interaction between proteins. In this work, we present hydrodynamic and electrophoretic experiments in an aqueous solution along with molecular dynamics and hydrodynamic modeling to monitor and compute biophysical properties of the interactions between the extracellular domain of the HER2 protein (eHER2) and the monoclonal antibody trastuzumab (TZM). The importance of this system relies on the fact that the overexpression of HER2 protein is related with the poor prognosis breast cancers (HER2++ positives), while the TZM is a monoclonal antibody for the treatment of this cancer. We have found and characterized two different complexes between the TZM and eHER2 proteins (1:1 and 1:2 TZM:eHER2 complexes). The conformational features of these complexes regulate their hydrodynamic and electrostatic properties. Thus, the results indicate a high degree of molecular flexibility in the systems that ultimately leads to higher values of the intrinsic viscosity, as well as lower values of diffusion coefficient than those expected for simple globular proteins. A highly asymmetric charge distribution is detected for the monovalent complex (1:1 complex), which has strong implications in correlations between the experimental electrophoretic mobility and the modeled net charge. In order to understand the dynamics of these systems and the role of the specific domains involved, it is essential to find biophysical correlations between dynamics, macroscopic transport and electrostatic properties. The results should be of general interest for researchers working in this area.

The comparison of anthracycline-based and non-anthracycline-based regimens in adjuvant chemotherapy of HER2-positive non-metastatic breast cancers

Aim of the study

This study aimed to assess the efficacy of anthracycline-based (AB) and non-anthracycline-based (nAB) adjuvant therapies in the human epidermal growth factor receptor 2 (HER2)-positive non-metastatic BC (nMBC) patients.

Material and methods

This retrospective study included women with HER2-positive BCs (stage I–III) treated with trastuzumab from 2008 to 2017. The patients were divided into two groups, including 196 patients in group AB and 67 in group nAB.

Results

Cox’s proportional hazard regression analysis showed no unfavourable predictors for five-year overall survival (OS) and disease-free survival (DFS) except for stage and hormone therapy. The OS rate was 67.9% in group AB and 80.6% in group nAB (p = 0.630). The DFS rate was 61.6% in group AB compared with 67.1% in group nAB (p = 0.447).

Conclusions

The results showed no difference between the efficacies of AB and nAB regimens in HER2-positive nMBCs in adjuvant setting. Therefore, selecting the nAB regimen can reduce the serious damage caused by the AB regimen.

Reliability of algorithmic somatic copy number alteration detection from targeted capture data

Motivation

Whole exome and gene panel sequencing are increasingly used for oncological diagnostics. To investigate the accuracy of SCNA detection algorithms on simulated and clinical tumor samples, the precision and sensitivity of four SCNA callers were measured using 50 simulated whole exome and 50 simulated targeted gene panel datasets, and using 119 TCGA tumor samples for which SNP array data were available.

Results

On synthetic exome and panel data, VarScan2 mostly called false positives, whereas Control-FREEC was precise (>90% correct calls) at the cost of low sensitivity (<40% detected). ONCOCNV was slightly less precise on gene panel data, with similarly low sensitivity. This could be explained by low sensitivity for amplifications and high precision for deletions. Surprisingly, these results were not strongly affected by moderate tumor impurities; only contaminations with more than 60% non-cancerous cells resulted in strongly declining precision and sensitivity. On the 119 clinical samples, both Control-FREEC and CNVkit called 71.8% and 94%, respectively, of the SCNAs found by the SNP arrays, but with a considerable amount of false positives (precision 29% and 4.9%).

Discussion

Whole exome and targeted gene panel methods by design limit the precision of SCNA callers, making them prone to false positives. SCNA calls cannot easily be integrated in clinical pipelines that use data from targeted capture-based sequencing. If used at all, they need to be cross-validated using orthogonal methods.

Availability and implementation

Scripts are provided as supplementary information.

Supplementary information

Supplementary data are available at Bioinformatics online.

Trastuzumab combined with doublet or single-agent chemotherapy as first-line therapy for HER2-positive metastatic breast cancer

PURPOSE

To investigate the efficacy and safety of doublet versus single-agent chemotherapy (CT) plus trastuzumab (H) as first-line therapy for human epidermal growth factor 2 receptor (HER2)-positive metastatic breast cancer (MBC).

METHODS

We searched for randomized clinical trials (RCTs) that evaluated the treatment effects of single-agent or doublet CT+H as first-line therapies for HER2-positive MBC. The main outcomes measured for this study included the overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). A meta-analysis and trial sequential analysis (TSA) were performed, and the study quality was evaluated using the GRADE framework. The PROSPERO registry number of our analysis is CRD42016043766.

RESULTS

The results from four RCTs including 1044 participants were pooled. Moderate-quality evidence indicated that compared with single-agent CT+H, doublet CT+H correlated better with prolonged PFS (hazard ratio [HR] 0.69, 95% confidence interval [CI] 0.63-0.75, P < 0.0001) and OS (HR = 0.90, 95% CI 0.88-0.92, P < 0.0001). However, moderate-quality evidence revealed no significant difference between the two regimens regarding the ORR (relative risk [RR] = 1.07, 95% CI 0.98-1.17, P = 0.157), which was confirmed by TSA, indicating that the cumulative Z-curve entered the futility area. Moderate-quality evidence indicated that treatment-related grade 3 or 4 toxicities of thrombocytopenia (RR = 4.08, P = 0.000), nausea/vomiting (RR = 4.26, P = 0.002), diarrhea (RR = 2.81, P = 0.002), and stomatitis (RR = 5.02, P = 0.003) were observed more frequently with doublet CT+H than with single-agent CT+H.

CONCLUSIONS

Compared with single-agent CT, the combination of doublet CT with trastuzumab as first-line therapy for HER2-positive MBC is associated with longer PFS and OS, but more treatment-related grade 3 or 4 toxicities. Therefore, doublet CT appears to be an appropriate regimen for HER2-positive MBC with a good performance status.

PTEN expression as a predictor for the response to trastuzumab-based therapy in Her-2 overexpressing metastatic breast cancer

Background

Even though trastuzumab is an effective therapy in early stage Her-2+ breast cancer, 40–50% of advanced Her-2+ breast cancer patients develop trastuzumab resistance. A potential resistance mechanism is aberrant downstream signal transmission due to loss of phosphatase and tensin homologue (PTEN). This study investigated the relationship between the expression of PTEN and trastuzumab response in Her-2 overexpressing metastatic breast cancer patients.

Methods

Between 2000 and 2007, 164 patients with Her-2+ metastatic breast cancer received trastuzumab-based therapy in our institution. We analyzed PTEN status by immunohistochemistry of 115 available tumor tissues and analyzed associations with other histopathological parameters, response rate, progression free survival (PFS) and overall survival (OS) with a median follow-up of 60 months.

Results

Eighty patients were PTEN positive (69.6%) and 35 patients PTEN negative (30.4%). We found a significant association of the expression of PTEN and p53 (p = 0.041), while there was no association with grading, hormone receptor status, IGFR or MIB. We found significantly more cases with progressive disease under trastuzumab-based therapy in patients with PTEN positive breast cancers (p = 0.018), while there was no significant correlation with PFS or OS.

Conclusion

In Her-2-positive metastatic breast cancers, PTEN positivity was significantly associated with progressive disease, but not with PFS or OS.

Synergistic action of cisplatin and echistatin in MDA-MB-231 breast cancer cells

The aim of our study was to determine whether the use of cisplatin in the presence echistatin in MDA-MB-231 breast cancer cells leads to a reduction of toxic effects associated with the use of cisplatin. The expression of β₁-integrin and insulin-like growth factor 1 receptor (IGF-IR), signaling pathway protein expression: protein kinase B (AKT), mitogen-activated protein kinases (ERK1/ERK2), nuclear factor kappa B (NFκB), and caspase-3 and -9 activity was measured after 24 h of incubation with tested compounds to explain detailed molecular mechanism of induction of apoptosis. The viability of MDA-MB-231 breast cancer cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Annexin V-FITC/propidium iodide staining assay was performed to detect the induction of apoptosis. Inhibition DNA biosynthesis was determined by [³H]thymidine incorporation into DNA. The expression of of β₁-integrin, IGF-IR, AKT, ERK1/ERK2, NFκB, caspase-3 and -9 was evaluated using Western blot. The results suggest that treatment of MDA-MB-231 breast cancer cells for 24 h cisplatin plus echistatin severely inhibits cell growth and activates apoptosis by upregulation of caspase-3 and -9 expressions. The effect was stronger than treatment cisplatin and echistatin alone. In this study, we have found that cisplatin plus echistatin treatment decreases collagen biosynthesis in MDA-MB-231 breast cancer cells stronger than the individual compounds. The inhibition was found to be dependent on the β₁-integrin and IGF receptor activation. A significant reduction of ERK1/ERK2, AKT expression in cancer cells after cisplatin plus echistatin treatment was also found. The cancer cells treated by echistatin, cisplatin, and in particular the combination of both compounds drastically increased expression of NFκB transcription factor. Our results suggest that combined therapy cisplatin plus echistatin is a possible way to improve selectiveness of cisplatin. This mechanism probably is due to downregulation of expression of β₁-integrin and IGF-IR receptors, and the signaling pathway proteins induced by these receptors. Our results suggest that therapy cisplatin plus echistatin is a possible way to improve selectiveness of cisplatin.

Trastuzumab cardiotoxicity: from clinical trials to experimental studies

Epidermal growth factor receptor-2 (HER-2) is overexpressed in 20 to 25% of human breast cancers, which is associated with aggressive tumour growth and poor prognosis. Trastuzumab (Herceptin®) is a humanized monoclonal antibody directed against HER-2, the first highly selective form of therapy targeting HER-2 overexpressing tumours. Although initial trials indicated high efficacy and a favourable safety profile of the drug, the first large, randomized trial prompted a retrospective analysis of cardiac dysfunction in earlier trials utilizing trastuzumab. There has been ongoing debate on the cardiac safety of trastuzumab ever since, initiating numerous clinical and preclinical investigations to better understand the background of trastuzumab cardiotoxicity and evaluate its effects on patient morbidity. Here, we have given a comprehensive overview of our current knowledge on the cardiotoxicity of trastuzumab, primarily focusing on data from clinical trials and highlighting the main molecular mechanisms proposed.

LINKED ARTICLES

This article is part of a themed section on New Insights into Cardiotoxicity Caused by Chemotherapeutic Agents. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.21/issuetoc.

Use of a multiplexed immunoassay (PRO Onc assay) to detect HER2 abnormalities in circulating tumor cells of women with HER2-negative metastatic breast cancer: lack of response to HER2-targeted therapy

PURPOSE

Determination of HER2 status by testing circulating tumor cells (CTCs), compared to sampling tumor biopsies, may improve patient management by allowing ongoing assessment of HER2 status during the disease course. The PRO Onc assay (Prometheus Laboratories; San Diego, CA) is a multiplexed immunoassay that measures the expression and activation of HER2 in CTCs. In this study, we screened patients with metastatic HER2-negative breast cancer with the PRO Onc assay; patients with HER2 overexpression or activation received a trial of HER2-targeted therapy.

METHODS

In Part 1 of the trial, patients with HER2-negative breast cancer were screened with the PRO Onc assay to confirm the presence of a cohort that tested HER2-positive. After this finding was confirmed, patients in Part 2 of the study with HER2 abnormalities received a trial of treatment with trastuzumab/pertuzumab.

RESULTS

In Part 1, 31 of 57 specimens contained CTCs; of these, 12 (38 %) showed HER2 abnormalities by PRO Onc assay. In Part 2, 129 of 226 patients (57 %) had CTCs; 24 of these patients (19 %) had HER2 abnormalities detected. Fourteen patients were treated with HER2-targeted therapy. Twelve of 14 patients progressed within 6 weeks, one patient had a brief (12 weeks) partial response, and one patient was stable for 12 weeks.

CONCLUSIONS

HER2 overexpression or activation was detected by the PRO Onc assay in 22 % of HER2-negative patients with CTCs. However, HER2-targeted therapy was not effective in such patients. FISH and IHC staining remain the standards for HER2 determination.

Cardiotoxicity in targeted therapy for breast cancer: A study of the FDA adverse event reporting system (FAERS)

Purpose Cancer chemotherapy-induced cardiotoxicity is concerning. Certain anthracyclines and targeted therapies are known to have potential for cardiotoxicity, but existing trial evidence is inadequate to understand real-world patterns of cardiotoxicity with newer targeted therapies and their common combinations with older agents. This study evaluated chemotherapy-related cardiotoxicity reports for targeted therapies and their combinations in breast cancer patients. Methods The US Food and Drug Administration Adverse Event Reporting System (FAERS) database from January 2004 through September 2012 was used to summarize characteristics of reported cardiotoxicity events and their health outcomes. Disproportionality analyses with reporting odds ratios (ROR) and 95% confidence intervals (95% CI) were conducted to detect event signals using a case/non-case method for each targeted therapy and combination. Results A total of 59,739 cases of cardiotoxicity reports were identified; 937 cases identified targeted therapy as the suspect drug. Trastuzumab had the highest number of reports followed by bevacizumab and lapatinib. Proportions of reports of death and disability outcomes for each targeted therapy were approximately 20-25% of the total reports of serious events. Trastuzumab had the highest ROR as a single agent (ROR = 5.74; 95% CI = 5.29-6.23) or combination use of cyclophosphamide (ROR = 16.83; 95% CI = 13.32-21.26) or doxorubicin (ROR = 17.84; 95% CI = 13.77-23.11). Relatively low cardiotoxicity reporting rates were found with lapatinib, regardless of use with combination therapy. Conclusions Analysis of FAERS data identified signals for adverse cardiotoxicity events with targeted therapies and their combinations. Practitioners should consider factors that may increase the likelihood of cardiotoxicity when assessing treatment. Findings support continued surveillance, risk factor identification, and comparative studies.

Phase 1B/2 study of the HSP90 inhibitor AUY922 plus trastuzumab in metastatic HER2-positive breast cancer patients who have progressed on trastuzumab-based regimen

This open-label, multicenter, phase 1B/2 trial assessed AUY922 plus trastuzumab in patients with locally advanced or metastatic HER2-positive breast cancer previously treated with chemotherapy and anti-HER2 therapy. This study was composed of a dose-escalation part with AUY922 administered weekly at escalating doses with trastuzumab 2 mg/kg/week (phase 1B), followed by a phase 2 part using the same regimen at recommended phase 2 dose (RP2D). The primary objectives were to determine the maximum tolerated dose (MTD) and/or RP2D (phase 1B), and to evaluate preliminary antitumor activity (phase 2) of AUY922 plus trastuzumab at MTD/RP2D. Forty-five patients were treated with AUY922 plus trastuzumab (4 in phase 1B with AUY922 at 55 mg/m2 and 41 in phase 1B/2 with AUY922 at 70 mg/m2 [7 in phase 1B and 34 in phase 2]). One patient in phase 1B (70 mg/m2) experienced a dose-limiting toxicity (grade 3 diarrhea); the RP2D was weekly AUY922 70 mg/m2 plus trastuzumab. Of the 41 patients in the 70 mg/m2 cohort, the overall response rate (complete or partial responses) was 22.0% and 48.8% patients had stable disease. Study treatment-related adverse events occurred in 97.8% of patients; of these, 31.1% were grade 3 or 4. Forty-one patients (91.1%) reported ocular events (82.3% had grade 1 or 2 events). Two patients (4.4%) had ocular events leading to the permanent discontinuation of study treatment. AUY922 at 70 mg/m2 plus trastuzumab standard therapy is well tolerated and active in patients with HER2-positive metastatic breast cancer who progressed on trastuzumab-based therapy.

Neoadjuvant Sequential Docetaxel Followed by High-Dose Epirubicin in Combination With Cyclophosphamide Administered Concurrently With Trastuzumab. The DECT Trial

To report the results of the DECT trial, a phase II study of locally advanced or operable HER2-positive breast cancer (BC) treated with taxanes and concurrent anthracyclines and trastuzumab. Eligible patients (stage IIA-IIIB HER2-positive BC, 18-75 years, normal organ functions, ECOG ≤1, and left ventricular ejection fraction (LVEF) ≥55%) received four cycles of neoadjuvant docetaxel, 100 mg/m(2) intravenously, plus trastuzumab 6 mg/kg (loading dose 8 mg/kg) every 3 weeks, followed by four 3-weekly cycles of epirubicin 120 mg/m(2) and cyclophosphamide, 600 mg/m(2) , plus trastuzumab. Primary objective was pathologic complete response (pCR) rate, defined as ypT0/is ypN0 at definitive surgery. We enrolled 45 consecutive patients. All but six patients (13.3%) completed chemotherapy and all underwent surgery. pCR was observed in 28 patients (62.2%) overall and in 6 (66.7%) from the inflammatory subgroup. The classification and regression tree analysis showed a 100% pCR rate in patients with BMI ≥25 and with hormone negative disease. The median follow up was 46 months (8-78). Four-year recurrence-free survival was 74.7% (95%CI, 58.2-91.2). Seven patients (15.6%) recurred and one died. Treatment was well tolerated, with limiting toxicity being neutropenia. No clinical cardiotoxicity was observed. Six patients (13.4%) showed a transient LVEF decrease (<10%). In one patient we observed a ≥10% asymptomatic LVEF decrease persisting after surgery. Notwithstanding their limited applicability due to the current guidelines, our findings support the efficacy of the regimen of interest in the neoadjuvant setting along with a fairly acceptable toxicity profile, including cardiotoxicity. Results on BMI may invite further assessment in future studies. J. Cell. Physiol. 231: 2541-2547, 2016. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

Oral vinorelbine in combination with trastuzumab as a first-line therapy of metastatic or locally advanced HER2-positive breast cancer

PURPOSE

Vinorelbine-trastuzumab combination proved to be an effective first-line treatment for patients with locally advanced or metastatic breast cancer (MBC). Oral chemotherapy represents a step forward in MBC management. To improve patients' comfort using the oral form of vinorelbine, we conducted a multicenter phase II study to investigate the efficacy and safety of the oral vinorelbine-trastuzumab combination in women with MBC with human epidermal growth factor receptor 2 (HER2) overexpression.

METHODS

Main eligibility criteria: HER2-positive disease, no adjuvant chemotherapy within the last 6 months and no prior chemotherapy for MBC. Patients were treated with oral vinorelbine 80 mg/m(2) D1, D8, D15 (following first 3 administrations at 60 mg/m(2) during the first cycle) for a total of 8 cycles (1 cycle = 3 weeks), in combination with trastuzumab 6 mg/kg on D1 (loading dose: 8 mg/kg) every 3 weeks or 4 mg/kg (loading dose: 6 mg/kg) weekly. Response was evaluated every 2 cycles using RECIST 1.0.

PRIMARY ENDPOINT

objective response rate (ORR); secondary endpoints: duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

In the full population (n = 26), median age was 50.7 years and median WHO PS 0. Median disease-free interval was 50.7 months [95 % CI (43.6-57.9)]. In the evaluable patients population, ORR was 56 % [95 % CI (34.9-75.6)], including 3 complete responses (12 %) and 11 partial (44 %); 8 (32 %) patients had stable disease resulting in a clinical benefit (or disease control) rate of 88 % [95 % CI (68.8-97.5)]. Median DOR was 7.1 months [95 % CI (3.9-10.2)], median PFS 6.7 months (95 % CI 3.5-10), and median OS 27.9 months (95 % CI 17.4-38.3). Treatment was generally well tolerated with main observed grade 3/4 hematological toxicities being neutropenia (46 %) and anemia (4 %). Grade 3-4 nausea-vomiting were observed in 11.5 % of patients.

CONCLUSIONS

Our results confirm the efficacy of oral vinorelbine-trastuzumab combination as a first-line treatment in HER2-positive locally advanced or MBC patients with an acceptable safety profile. Oral vinorelbine-trastuzumab optimizes the convenience of this chemotherapy regimen, especially for patients receiving trastuzumab every 3 weeks.

Anti-HER2 Therapy Beyond Second-Line for HER2-Positive Metastatic Breast Cancer: A Short Review and Recommendations for Several Clinical Scenarios from a Spanish Expert Panel

BACKGROUND

The aim of this project was to provide an expert opinion regarding anti-human epidermal growth factor receptor 2 (HER2) therapy beyond second-line treatment of metastatic breast cancer (mBC).

METHODS

A group of experts discussed specific issues concerning anti-HER2 therapy in late-line settings in mBC.

RESULTS

Trastuzumab emtansine (T-DM1) or dual HER2 blockade appeared to be good options for HER2-positive mBC after ≥ 2 HER2-targeted therapies. Once an objective response has been achieved with anti-HER2-containing therapy, the anti-HER2 agent can be continued until progression of the disease, unacceptable toxicity or patient decision. mBC treated with ≥ 3 consecutive lines of anti-HER therapy, ≥ 1 being a dual HER2 blockade and with early progression of disease during a fourth or later-line treatment, are clinically resistant to anti-HER therapy. For progression of metastasis in the brain after anti-HER2 therapy, lapatinib and chemotherapy appear to be a good alternative after best local treatment.

CONCLUSIONS

Further clinical trials are needed to provide valuable knowledge about the best treatment options in the later settings of mBC.

Assessing the role of platinum agents in aggressive breast cancers

As anticipated by their structure and mechanism of action, platinum analogs exhibit clinically significant antitumor activity in the more aggressive forms of breast cancer, both alone and in combination with other cytotoxic agents and targeted therapies. In early-stage human epidermal growth factor receptor-2 (HER2)-positive breast cancer, the administration of carboplatin together with a taxane (usually docetaxel) and trastuzumab (and pertuzumab in the neoadjuvant setting) is a standard of care regimen. In BRCA1 mutation carriers, neoadjuvant treatment with single-agent cisplatin results in a high pathologic complete response (pCR) rate. In both BRCA-mutated and sporadic triple-negative breast cancer, the addition of carboplatin to neoadjuvant chemotherapy significantly increases pCR rates. Despite these encouraging results, many questions remain about the role of platinum analogs in these patient populations, including their optimal doses and schedules, and utility in patients with advanced stage disease. A number of these questions are addressed by ongoing trials.

Final overall survival analysis of a phase II trial evaluating vinorelbine and lapatinib in women with ErbB2 overexpressing metastatic breast cancer

Lapatinib plus capecitabine (lap+cap) is approved as treatment for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC), who have progressed on prior trastuzumab in the metastatic setting. We previously reported progression-free survival (PFS), overall survival (OS) and safety results from this open-label, multicentre, phase II study (VITAL; NCT01013740) conducted in women with HER2 positive MBC, to evaluate the efficacy and safety of lap plus vinorelbine (lap+vin), an important chemotherapy option for MBC, compared with lap+cap. In total, 112 patients were randomised 2:1 to treatment with lap+vin (N = 75) or lap+cap (N = 37). Results showed that the median PFS (primary endpoint) and OS (secondary endpoint) post-randomisation were comparable between treatment arms, with no new safety signals detected. Here, we assessed the final OS in this study at 40 months post-randomisation. At the time of final analyses, 24 (32%) patients were ongoing in the lap+vin arm, compared with 14 (38%) patients in the lap+cap arm (92% in both arms had discontinued treatment). Median OS in the lap+vin arm was 23.3 months (95% confidence intervals [CI]: 18.5, 31.1), compared with 20.3 months (95% CI: 16.4, 31.8) in the lap+cap arm. The median follow-up in the lap+vin arm was 18.86 months (95% CI: 10.68, 26.02), compared with 19.38 (95% CI: 25.56) months in the lap+cap arm. Similar rates of death (56-57%) were observed in both arms. The final OS was consistent with the previously reported data and suggest that lap+vin offers an effective treatment option for women with HER2-positive MBC.

Right ventricle failure associated wıth trastuzumab

Trastuzumab (TZ), a monoclonal antibody against human epidermal growth factor receptor type 2 (HER2), is an important biological agent used for the treatment of positive breast cancer. This paper presents a 46-year-old female patient who developed right heart failure and right ventricular dysfunction while on TZ due to breast cancer, and returned to normal following the discontinuation of the drug. As far as we know, this is the first case report related to a patient presenting with right ventricular dysfunction and induced cardiotoxicity while on TZ.

HER2-directed therapy: current treatment options for HER2-positive breast cancer

Over the past decade, the management of HER2-positive breast cancer has evolved dramatically. In addition to advances in screening, genetic testing, imaging, surgical and radiation techniques, innovations in medical therapy including widespread use of HER2-directed therapy in early and advanced breast cancer have revolutionized breast cancer care and changed the natural history of HER2-positive breast cancer. A substantial number of HER2-targeted agents are being developed including monoclonal antibodies, small molecule inhibitors, and antibody drug conjugates. Trastuzumab is the prototype HER2-directed therapy that was introduced in the late 1990s for the management of metastatic breast cancer and later showed efficacy in early stage disease. Despite the practice changing impact of trastuzumab and improvement in outcomes of women with HER2-positive breast cancer resistance to trrastuzumab is a major clinical issue, occurring in both early stage and advanced disease, and new treatment strategies are clearly required. Combining HER2-targeted agents and dual HER2 blockade has been successful in early and advanced breast cancer. Furthermore, selected delivery of potent chemotherapeutic agent coupled with HER2 inhibition promises new treatment options. This review is focused on current HER2-directed treatments for women with HER2-positive breast cancer including monoclonal antibodies, small molecule inhibitors, and antibody drug conjugates.

Trastuzumab increases the sensitivity of HER2-amplified human gastric cancer cells to oxaliplatin and cisplatin by affecting the expression of telomere-associated proteins

HER2 amplification occurs in ~20% of gastric cancer (GC) cases; however, in gastric and gastroesophageal junction cancer with HER2 gene amplification, trastuzumab in combination with cisplatin (DDP)-based chemotherapy has been reported to improve the oncological outcome. The aim of the present study was to evaluate the combined antitumor efficacy of trastuzumab and various platinum agents in GC cells and to elucidate mechanisms that may be involved in the interaction between trastuzumab and the platinum agents. The in vitro chemosensitivity of the GC cells to platinum agents was evaluated using the CellTiter 96^® AQueous One Solution Cell Proliferation Assay kit. Treatment with 1.0μg/ml trastuzumab for 48 h significantly increased the sensitivity of NCI-N87 cells with HER2 amplification to oxaliplatin (Oxa) and DDP. This chemosensitivity was most prominent in the NCI-N87 cells, in which the half maximal inhibitory concentration of Oxa and DDP was decreased to ~3.29 and 6.91 times, respectively. The apoptotic effect of the platinum agents was evaluated by double-staining the GC cells with Annexin V-fluorescein isothiocyanate and propodium iodide. Consistent with the chemosensitivity analysis, apoptotic analysis indicated that trastuzumab significantly increased Oxa- and DDP-induced apoptosis in the NCI-N87 cells. Furthermore, the mRNA expression levels of various telomere-associated genes was determined by performing quantitative reverse transcription-polymerase chain reactions in a number of GC cell lines, and revealed that trastuzumab (alone and in combination with DDP) may downregulate the mRNA expression levels of the TPP1, TRF1, TRF2, TRF2IP and POT1 genes. However, western blot analysis demonstrated that trastuzumab (alone and in combination with DDP) may significantly downregulate the protein expression levels of telomeric repeat binding factor 2, protection of telomere 1 and TPP1 (formerly known as TINT1, PTOP and PIP). The results of the present study indicate a potential role of low-dose trastuzumab administration for increasing Oxa and DDP sensitivity in HER2-amplified GC cells, possibly via the downregulation of telomere-associated gene expression.

The downregulation of miR-200c/141 promotes ZEB1/2 expression and gastric cancer progression

Gastric cancer is the fourth most common malignancy in the world. Although microRNA-200 (miR-200) family members are thought to play roles in tumorigenesis, their functions in carcinogenesis are tumor specific, and the underlying mechanism of action still remains elusive. Few studies to date have addressed the dysregulation and function of miR-200 family members in gastric cancer progression. Here, we report that the miR-200 family members, miR-200c and miR-141, were significantly downregulated in gastric cancer specimens and gastric cancer cell lines. Importantly, on clinical samples, the expression of miR-200c and miR-141 was inversely correlated with TNM stage, tumor invasion depth (T), tumor embolus and disease-free survival. Wound-healing assay results showed that co-transfected miR-200c/141 could inhibit the migration and invasion capability of the gastric cell line SGC-7901. We also found that miR-200c and miR-141 directly targeted zinc finger E-box-binding homeobox 1/2 (ZEB1/2) and upregulated E-cadherin expression. In specimens from gastric cancer patients, reduced expression of miR-200c/141 was associated with increased expression of ZEB1 and/or ZEB2. In addition, the downregulation of miR-200c and miR-141 was found to be due to a highly methylated CpG island located upstream of their genomic sequence and/or upregulated TGF-β signaling. Treatment with the chemotherapeutic agent decitabine, a known DNA methyltransferase inhibitor, increased miR-200c/141 expression and ameliorated decreased expression of miR-200c/141 induced by TGF-β in SGC-7901 cells. Our study revealed that miR-200c/141 was downregulated by CpG island methylation and TGF-β signaling, which decreased ZEB1/2 expression and increased E-cadherin expression to inhibit migration and invasion of gastric cancer cells and provides powerful evidence for the application of decitabine in gastric cancer treatment.

Computational methods for detecting copy number variations in cancer genome using next generation sequencing: principles and challenges

Accurate detection of somatic copy number variations (CNVs) is an essential part of cancer genome analysis, and plays an important role in oncotarget identifications. Next generation sequencing (NGS) holds the promise to revolutionize somatic CNV detection. In this review, we provide an overview of current analytic tools used for CNV detection in NGS-based cancer studies. We summarize the NGS data types used for CNV detection, decipher the principles for data preprocessing, segmentation, and interpretation, and discuss the challenges in somatic CNV detection. This review aims to provide a guide to the analytic tools used in NGS-based cancer CNV studies, and to discuss the important factors that researchers need to consider when analyzing NGS data for somatic CNV detections.

High incidence of febrile neutropenia following adjuvant breast chemotherapy with docetaxel, carboplatin and trastuzumab

SUMMARY 

Aim: To determine the incidence of febrile neutropenia (FN) following adjuvant chemotherapy with docetaxel, carboplatin and trastuzumab (TCH) for early-stage breast cancer and the grade of neutropenia after cycle one. Methods: A retrospective multicenter audit of patients with early-stage breast cancer treated with TCH, was conducted at four Australian hospitals between October 2009 and September 2013. Results: Of 79 patients analyzed, data from 78 women were evaluated for FN incidence and data from 64 women were evaluated for grade of neutropenia. After cycle one of TCH, 26 patients developed FN (33.3%). Following all cycles, 32 patients developed FN (41.0%). There was no statistical difference in the incidence of FN between hospitals or between age groups (above or below 65 years). After cycle one, ten patients developed grade 3 neutropenia (15.6%) and 37 patients developed grade 4 neutropenia (57.8%). Conclusion: This study demonstrates a high incidence of FN post-TCH chemotherapy thus supporting the use of granulocyte colony-stimulating factor as primary prophylaxis.

Metastatic human epidermal growth factor 2 (HER2/neu) amplified breast cancer with acute fulminant hepatitis responding to trastuzumab, pertuzumab and carboplatin

A 30-year-old woman presented to an outside hospital with pain in the right upper abdomen. Imaging revealed over 100 liver lesions, the largest measuring 74 mm×71 mm, and multiple lytic bone lesions. An outpatient liver biopsy showed a poorly differentiated adenocarcinoma favouring a breast primary. The tumour was oestrogen and progesterone receptor negative, but human epidermal growth factor 2 (HER2/neu) amplified. In her second clinic visit she had decompensated liver failure manifested by new-onset ascites and jaundice. Initially, the chemotherapy plan was for docetaxel, pertuzumab and trastuzumab, but given her severe liver dysfunction we used a combination of carboplatin, pertuzumab and trastuzumab as an inpatient. She was hospitalised for 14 days and eventually discharged with a marked improvement of her symptoms and liver tests. She subsequently completed five outpatient chemotherapy cycles. We showed that carboplatin is a possible alternative to docetaxel when severe liver dysfunction precludes docetaxel's use in combination with pertuzumab and trastuzumab.

The first two lines of chemotherapy for anthracycline-naive metastatic breast cancer: a comparative study of the efficacy of anthracyclines and non-anthracyclines

For anthracycline-naive metastatic breast cancer (AN-MBC), early anthracycline treatment is a common practice. However, with the availability of newer chemotherapies, comparative studies on the efficacy of anthracyclines and non-anthracyclines as early treatments for AN-MBC are lacking. We collected retrospective clinicopathological data from 253 AN-MBC patients treated at National Taiwan University Hospital between 2001 and 2006. Patients were categorised into anthracycline or non-anthracycline groups according to their regimens in the first two lines of chemotherapy. The overall survival (OS, 33.3 vs. 34.2 months, p = 0.179), time to treatment failure of the first two lines of chemotherapy drugs (13.3 vs. 12.7 months, p = 0.104) and best composite response rate (59.5% vs. 61.1%, p = 0.81) were not significantly different between the two groups. Multivariate analysis showed that early anthracycline treatment was not a significant prognostic factor of OS (p = 0.052). Thus, the results of this study show that anthracyclines may not be necessary as an early treatment option for AN-MBC.

Targeted therapy in HER2-positive breast cancer

Treatment options for breast cancer vary based on tumor surface markers and clinical factors, including cytotoxic chemotherapy, hormonal therapy, biological therapy or a combination thereof. An important molecular determinant of therapy is the human epidermal growth factor receptor 2 (HER2) positivity of the tumor, which has been identified in 20-25% of breast cancers and is a prognostic marker of poor outcome. The advent of HER2-targeted therapies has significantly improved the survival of patients with HER2-positive breast cancer. This review focuses on current HER2-targeted therapeutic options for patients with HER2-positive breast cancer, including monoclonal antibodies and tyrosine kinase inhibitors (TKIs).

Drug resistance and the role of combination chemotherapy in improving patient outcomes

Resistance to cancer chemotherapy is a common phenomenon especially in metastatic breast cancer (MBC), a setting in which patients typically have had exposure to multiple lines of prior therapy. The subsequent development of drug resistance can result in rapid disease progression during or shortly after completion of treatment. Moreover, cross-class multidrug resistance limits patient treatment choices, particularly in a setting where treatments options are few. One attempt to minimize the impact of drug resistance has been the concurrent use of two or more chemotherapy agents with unrelated mechanisms of action and differing modes of drug resistance, with the intent of blocking the development of multiple intracellular escape pathways essential for tumor survival. Within the past decade, an array of mechanistically diverse agents has augmented the list of combination regimens that may be both synergistic and efficacious in pretreated MBC. The aim of this paper is to review mechanisms of resistance to common chemotherapy agents and to consider current combination treatment options for heavily pretreated and/or drug-resistant patients with MBC.

Polymalic acid nanobioconjugate for simultaneous immunostimulation and inhibition of tumor growth in HER2/neu-positive breast cancer

Breast cancer remains the second leading cause of cancer death among women in the United States. Breast cancer prognosis is particularly poor in case of tumors overexpressing the oncoprotein HER2/neu. A new nanobioconjugate of the Polycefin(TM) family of anti-cancer drugs based on biodegradable and non-toxic polymalic acid (PMLA) was engineered for a multi-pronged attack on HER2/neu-positive breast cancer cells. An antibody-cytokine fusion protein consisting of the immunostimulatory cytokine interleukin-2 (IL-2) genetically fused to an antibody specific for human HER2/neu [anti-HER2/neu IgG3-(IL-2)] was covalently attached to the PMLA backbone to target HER2/neu expressing tumors and ensure the delivery of IL-2 to the tumor microenvironment. Antisense oligonucleotides (AON) were conjugated to the nanodrug to inhibit the expression of vascular tumor protein laminin-411 in order to block tumor angiogenesis. It is shown that the nanobioconjugate was capable of specifically binding human HER2/neu and retained the biological activity of IL-2. We also showed the uptake of the nanobioconjugate into HER2/neu-positive breast cancer cells and enhanced tumor targeting in vivo. The nanobioconjugate exhibited marked anti-tumor activity manifested by significantly longer animal survival and significantly increased anti-HER2/neu immune response in immunocompetent mice bearing D2F2/E2 murine mammary tumors that express human HER2/neu. The combination of laminin-411 AON and antibody-cytokine fusion protein on a single polymeric platform results in a new nanobioconjugate that can act against cancer cells through inhibition of tumor growth and angiogenesis and the orchestration of an immune response against the tumor. The present Polycefin(TM) variant may be a promising agent for treating HER2/neu expressing tumors and demonstrates the versatility of the Polycefin(TM) nanobioconjugate platform.

Adjuvant trastuzumab for 6 months is effective in patients with HER2-positive stage II or III breast cancer

OBJECTIVE

The optimal duration of adjuvant trastuzumab treatment in patients with HER2-positive breast cancer is not known. The aim of this study was to evaluate the efficacy of 6 months of adjuvant trastuzumab treatment in patients with stage II or III HER2-positive breast cancer.

METHODS

The records of patients with HER2-positive stage II or III breast cancer who were admitted to the Breast Center of Taipei Medical University Hospital and Yuan's General Hospital between 2000 and 2008 were reviewed. All patients received adjuvant trastuzumab at an initial dose of 4 mg/kg followed by a maintenance dose of 2 mg/kg/week for 22 weeks in combination with chemotherapy.

RESULTS

A total of 51 patients were included with a mean age of 46.9 years. Approximately 55% of the patients had stage III disease. The mean follow-up time from initiation of treatment was 45.2 months (range, 0.9 to 85 months). During follow-up, 46 patients (90.2%) did not experience tumor recurrence. The mean estimated disease free survival was 80.2 months. The estimated 1- , 2-, 5-, and 7-year survival rates were 97.9%, 93.1%, 93.1%, and 93.1%, respectively. The most common adverse effects were gastrointestinal symptoms (21.6%), chills (17.6%), dizziness (9.8%), and bone pain (7.8%). No cardiac or hematologic adverse events occurred.

CONCLUSION

Adjuvant therapy with trastuzumab for 6 months resulted in a clinical benefit in patients with HER2-positive breast cancer.

Weekly paclitaxel/carboplatin/trastuzumab therapy improves pathologic complete remission in aggressive HER2-positive breast cancers, especially in luminal-B subtype, compared with a once-every-3-weeks schedule

BACKGROUND

The efficacy and tolerability of two different schedules of paclitaxel, carboplatin, and trastuzumab (PCarH) for HER2-positive, locally aggressive (stage IIB-IIIC) breast cancers were evaluated in this phase II trial.

METHODS

Patients were randomly assigned to receive either weekly (12 doses over 16 weeks) or once-every-3-weeks (4 doses over 12 weeks) treatment. The primary endpoint was pathologic complete remission (pCR) in the breast and axilla. To detect an assumed 35% pCR absolute difference between the two schedules, a minimum of 26 assessable patients in each group was required (two-sided α = 0.05, β = 0.2).

RESULTS

A total of 56 patients were enrolled (weekly group, n = 29; every-3-weeks group, n = 27). In the intent-to-treat analysis, pCR in the breast/axilla were found in 31 patients (55%; 95% confidence interval [CI]: 41%-69%). Compared with the every-3-weeks schedule, the weekly administration achieved higher pCR (41% vs. 69%; p = .03). After adjustment for clinical and pathological factors, the weekly administration was more effective than the every-3-weeks schedule, with hazard ratio of 0.3 (95% CI: 0.1-0.9; p = .03). Interestingly, weekly administration resulted in high pCR rates in both luminal-B (HER2-positive) and ERBB2+ tumors (67% vs. 71%; p = .78), whereas luminal-B (HER2-positive) tumors benefited less from the every-3-weeks schedule compared with the ERBB2+ tumors (21% vs. 62%, p = .03). These results remain after multivariate adjustment, showing weekly administration was more effective in the luminal-B (HER2-positive) subgroup (p = .02) but not in the ERBB2+ subgroup (p = .50).

CONCLUSION

A more frequent administration might improve the possibility of eradicating invasive cancer in the breast and axilla, especially in the luminal-B (HER2-positive) subtype. Further studies to validate our findings are warranted.

Pertuzumab : evolving therapeutic strategies in the management of HER2-overexpressing breast cancer

INTRODUCTION

HER2 overexpression or amplification is present in approximately one-fifth of breast cancers and historically was associated with aggressive disease and poorer prognosis. The introduction of the humanized monoclonal antibody trastuzumab dramatically improved disease-free survival (DFS) and overall survival (OS) in this subgroup. As the majority of patients with metastatic disease ultimately develop resistance to trastuzumab, a need exists for more effective targeted therapies. Pertuzumab is an anti-HER2/neu-targeted therapy in the late stages of clinical development. The combination of pertuzumab, trastuzumab and docetaxel has been found to have an OS benefit in patients with HER2 positive metastatic breast cancer (MBC) when used in the first-line setting. This reflects a new standard of care, and pertuzumab was recently approved for this indication by the Food and Drug Administration (FDA). The efficacy of pertuzumab and trastuzumab in conjunction with chemotherapy is currently being evaluated in the adjuvant setting.

AREAS COVERED

This article provides an overview of preclinical investigations in addition to reviewing pertinent Phase I, Phase II and Phase III clinical trials.

EXPERT OPINION

Pertuzumab, in combination with the humanized monoclonal antibody trastuzumab, and docetaxel is a standard of care for patients with previously untreated metastatic breast cancer based on the CLEOPATRA study showing a survival benefit. There is no increase in cardiac toxicity with the combined HER2-targeted therapy. Future issues will address appropriate sequencing and combination with other anti-HER2-targeted therapies and/or chemotherapy.

Liposomal Doxorubicin in the treatment of breast cancer patients: a review

Drug delivery systems can provide enhanced efficacy and/or reduced toxicity for anticancer agents. Liposome drug delivery systems are able to modify the pharmacokinetics and biodistribution of cytostatic agents, increasing the concentration of the drug released to neoplastic tissue and reducing the exposure of normal tissue. Anthracyclines are a key drug in the treatment of both metastatic and early breast cancer, but one of their major limitations is cardiotoxicity. One of the strategies designed to minimize this side effect is liposome encapsulation. Liposomal anthracyclines have achieved highly efficient drug encapsulation and they have proven to be effective and with reduced cardiotoxicity, as a single agent or in combination with other drugs for the treatment of either anthracyclines-treated or naïve metastatic breast cancer patients. Of particular interest is the use of the combination of liposomal anthracyclines and trastuzumab in patients with HER2-overexpressing breast cancer. In this paper, we discuss the different studies on liposomal doxorubicin in metastatic and early breast cancer therapy.

Recent advances in novel targeted therapies for HER2-positive breast cancer

The monoclonal antibody trastuzumab has improved the outcomes of patients with breast cancer that overexpresses the human epidermal growth factor receptor 2 (HER2). However, despite this advancement, many tumors develop resistance and novel approaches are needed. Recently, a greater understanding of cellular biology has translated into the development of novel anti-HER2 agents with varying mechanisms of action. The small molecule tyrosine kinase inhibitor lapatinib has demonstrated activity in HER2-positive metastatic breast cancer (MBC) and in the preoperative setting. Pertuzumab is a monoclonal antibody with a distinct binding site from trastuzumab, which inhibits receptor dimerization. In recent studies, the addition of pertuzumab to combination therapy has led to improvements in progression-free survival in patients with HER2-positive MBC and higher response rates in the preoperative setting. An alternative approach is the use of novel antibody-drug conjugates such as trastuzumab-emtansine, which recently demonstrated activity in MBC. Neratinib, a pan-HER tyrosine kinase inhibitor, which irreversibly inhibits HER1 and HER2, also has proven activity in MBC. A range of compounds is being developed to attempt to overcome trastuzumab resistance by targeting heat shock protein 90, a molecular chaperone required for the stabilization of cellular proteins. Furthermore, agents are being developed to inhibit the mammalian target of rapamycin, a downstream component of the PTEN/PI3K pathway, which has been implicated in trastuzumab resistance. Finally, there are emerging data indicating that combinations of anti-HER2 agents may circumvent resistance mechanisms and improve patient outcomes. In this review, recent data on these emerging agents and novel combinations for HER2-positive breast cancer are discussed.

Truncated p110 ERBB2 induces mammary epithelial cell migration, invasion and orthotopic xenograft formation, and is associated with loss of phosphorylated STAT5

Truncated-ERBB2 isoforms (t-ERBB2s), resulting from receptor proteolysis or alternative translation of the ERBB2 mRNA, exist in a subset of human breast tumors. t-ERBB2s lack the receptor extracellular domain targeted by therapeutic anti-ERBB2 antibodies and antibody–drug conjugates, including trastuzumab, trastuzumab-DM1 and pertuzumab. In clinical studies, expression of t-ERBB2 in breast tumors correlates with metastasis as well as trastuzumab resistance. By using a novel immuno-microarray method, we detect a significant t-ERBB2 fraction in 18 of 31 (58%) of immunohistochemistry (IHC)3+ ERBB2+ human tumor specimens, and further show that t-ERBB2 isoforms are phosphorylated in a subset of IHC3+ samples (10 of 31, 32%). We investigated t-ERBB2 biological activity via engineered expression of full-length and truncated ERBB2 isoforms in human mammary epithelial cells (HMECs), including HMEC and MCF10A cells. Expression of p110 t-ERBB2, but not p95m (m=membrane, also 648CTF) or intracellular ERBB2s, significantly enhanced cell migration and invasion in multiple cell types. In addition, only expression of the p110 isoform led to human breast epithelial cell (HMLE) xenograft formation in vivo. Expression of t-ERBB2s did not result in hyperactivation of the phosphoinositide kinase-3/AKT or mitogen-activated protein kinase signaling pathways in these cells; rather, phosphoproteomic array profiling revealed attenuation of phosphorylated signal transducer and activator of transcription 5 (STAT5) in p110-t-ERBB2-expressing cells compared to controls. Short hairpin-mediated silencing of STAT5 phenocopied p110-t-ERBB2-driven cell migration and invasion, while expression of constitutively active STAT5 reversed these effects. Thus, we provide novel evidence that (1) expression of p110 t-ERBB2 is sufficient for full transformation of HMEC, yielding in vivo xenograft formation, and (2) truncated p110 t-ERBB2 expression is associated with decreased phosphorylation of STAT5.

Weekly paclitaxel plus trastuzumab in metastatic breast cancer pretreated with anthracyclines--a phase II multipractice study

Background

The 3-weekly combination of trastuzumab and paclitaxel has been approved for the treatment of advanced breast cancer based on a large pivotal study. However, mono and combination chemotherapy trials suggest that weekly paclitaxel has a better therapeutic index, especially in the palliative setting. The present trial examined the efficacy and safety of weekly paclitaxel over a limited duration combined with continued trastuzumab in HER2+ patients.

Methods

Patients with histologically confirmed metastatic breast cancer overexpressing HER2 were eligible if pretreated with anthracycline in either the adjuvant or palliative setting. Treatment consisted of weekly trastuzumab (2 mg/kg/week for up to one year after a loading dose of 4 mg/kg in week 1) and paclitaxel (90 mg/m², administered in weeks 1–6 and 8–13).

Results

Twenty-seven German centers enrolled 121 patients. The median number of metastatic sites was two (range 1–5); 38% of patients had received chemotherapy for advanced disease. After a median 42 weeks of trastuzumab treatment, limited by disease progression in roughly half the patients, a best objective response rate (complete response + partial response) of 76% was achieved, including complete remissions in 29%. 74% of patients lived without tumor progression at six months. Median progression-free and overall survival were 9.4 (95% confidence interval [CI]: 8.1–11.3) and 22 months (95% CI: 17–46). After alopecia, Common Toxicity Criteria grade ≥2 toxicity was predominantly hematological (leukopenia [31%] and anemia [41%]); however, thrombocytopenia occurred in only 5%. Neurotoxicity was remarkably low. Two cardiac events (grades 2 and 3) were presumed treatment-related.

Conclusions

Weekly paclitaxel plus trastuzumab allows an increased dose density and offers an attractive and effective alternative to the conventional schedule. Limiting the duration of cytotoxic therapy to 3 months seems to be an option to reduce neurotoxicity without impairing long-term outcome.

Increased signalling of EGFR and IGF1R, and deregulation of PTEN/PI3K/Akt pathway are related with trastuzumab resistance in HER2 breast carcinomas

Background:

Trastuzumab resistance hampers its well-known efficacy to control HER2-positive breast cancer. The involvement of PI3K/Akt pathway in this mechanism is still not definitively confirmed.

Methods:

We selected 155 patients treated with trastuzumab after development of metastasis or as adjuvant/neoadjuvant therapy. We performed immunohistochemistry for HER2, ER/PR, epidermal growth factor 1-receptor (EGFR), α-insulin-like growth factor 1-receptor (IGF1R), phosphatase and tensin homologue (PTEN), p110α, pAkt, pBad, pmTOR, pMAPK, MUC1, Ki67, p53 and p27; mutational analysis of PIK3CA and PTEN, and PTEN promoter hypermethylation.

Results:

We found 46% ER/PR-positive tumours, overexpression of EGFR (15%), α-IGF1R (25%), p110α (19%), pAkt (28%), pBad (22%), pmTOR (23%), pMAPK (24%), MUC1 (80%), PTEN loss (20%), and PTEN promoter hypermethylation (20%). PIK3CA and PTEN mutations were detected in 17% and 26% tumours, respectively. Patients receiving adjuvant trastuzumab with α-IGF1R or pBad overexpressing tumours presented shorter progression-free survival (PFS) (all P⩽0.043). Also, p110α and mTOR overexpression, liver and brain relapses implied poor overall survival (OS) (all P⩽0.041). In patients with metastatic disease, decreased PFS correlated with p110α expression (P=0.024), whereas for OS were the presence of vascular invasion and EGFR expression (P⩽0.019; Cox analysis).

Conclusion:

Our results support that trastuzumab resistance mechanisms are related with deregulation of PTEN/PI3K/Akt/mTOR pathway, and/or EGFR and IGF1R overexpression in a subset of HER2-positive breast carcinomas.

Docetaxel, Carboplatin, and Trastuzumab (TCH) for HER2-Positive Breast Cancer

The complexity of cancer chemotherapy requires pharmacists be familiar with the complicated regimens and highly toxic agents used. This column reviews various issues related to preparation, dispensing, and administration of antineoplastic therapy, and the agents, both commercially available and investigational, used to treat malignant diseases.

A phase II study of neoadjuvant chemotherapy with docetaxel, cisplatin and trastuzumab for T2 breast cancers

PURPOSE

Preclinical data indicate that the combination of docetaxel, cisplatin and trastuzumab (TCH) may have the potential for clinically significant activity against breast cancers that overexpress the her2/neu gene (HER2). An open-label phase II trial was designed to investigate the response rate and toxicity profile of TCH in breast cancer patients with a primary tumor 2-5 cm in diameter (T2) in its original size.

METHODS

Thirty breast cancer patients with HER2-overexpressing tumors were enrolled. Patients received 6 cycles of docetaxel at 60 mg/m(2) and cisplatin at 50 mg/m(2) given on day 1 and then every 21 days. Trastuzumab was given on day 1, cycle 1 (4 mg/kg), and then continued weekly at 2 mg/kg for 1 year or until disease progression. Tumor measurements were obtained at baseline as well as after 3 and 6 cycles of chemotherapy.

RESULTS

We identified 29 breast cancer patients in Taiwan, of whom 13 (44.8%) had pathological complete responses. No cardiac toxicity was observed. Hematologic grade 4 or 3 toxicities were observed in 1 of 28 patients. Non-hematologic grade 4 or 3 toxicities with a reverse pattern were observed in 6 of 29 patients.

CONCLUSIONS

The results of our study indicate that TCH neoadjuvant chemotherapy is feasible and active in T2 HER2-overexpressing breast cancer patients in terms of pathological complete response rate, complete response, partial response and manageable toxicities.

Platinum-based compounds for the treatment of metastatic breast cancer

The role of platinum-based compounds (PBCs) in the treatment of metastatic breast cancer (MBC) has been extensively studied. As single agents, high response rates have been observed in first-line therapy, while results in pretreated patients were discouraging. Regimens containing cisplatin/carboplatin together with taxanes showed the highest efficacy and safety as both first-line and second-line therapy. When administered with vinorelbine, the combination was also active and well tolerated in anthracycline- and taxane-pretreated patients. Combining PBCs with etoposide or nucleoside analogues showed moderate activity, yet high toxicity in the case of etoposide. The overall results for the combination with anthracyclines were disappointing. Addition of trastuzumab to PBC combinations showed remarkable activity and good tolerability in patients with HER2/neu overexpression. The use of cisplatin or carboplatin alongside novel targeted therapeutics for patients with triple-negative MBC seems promising and is being further evaluated. The use of PBCs against MBC requires careful patient selection and combination with the right chemotherapeutic agent.